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Fundamentals of Pro/MECHANICA Structure/Thermal

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T741-320-01 11/10/01 Initial Printing of Fundamentals of Pro/MECHANICA Structure/Thermal

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Training Agenda


Day 1

Introduction to Pro/MECHANICA

Simplifying Models with Idealizations

Optimizing Models for Analysis

Day 2

Assigning Material Properties

Applying Constraints

Simulating Applied Loads

Day 3

Running and Evaluating Analyses

Analysis and Results: Examples

Day 4

Running Sensitivity and Optimization Studies

Running Analyses

Advanced Exercises

Day 5

Fatigue Advisor

Student Projects


Table of Contents


INTRODUCTION TO PRO/MECHANICA 1-1

OVERVIEW ...................................................................................................................... 1-2

Structure Simulation...........................................................................................................1-2

RUNNING ANALYSES.................................................................................................... 1-4

Analysis Design Scenario...................................................................................................1-4

Identifying the Design Requirements .................................................................................1-4

Creating the Bracket Design...............................................................................................1-5

Model Idealization..............................................................................................................1-6

Creating the Design Parameters .........................................................................................1-9

Running Sensitivity Studies .............................................................................................1-10

Running Optimization Studies..........................................................................................1-11

USER INTERFACE: INTEGRATED MODE I .............................................................. 1-12

Using the MECHANICA Menu .......................................................................................1-12

Using Toolbar Icons .........................................................................................................1-12

Accessing the Object Sensitive Menu from the MODEL TREE......................................1-13

Using the Icons in the Graphic Window...........................................................................1-14

EXERCISE 1: Create the Bracket Design ........................................................................1-15

EXERCISE 2: Assign the Material Properties .................................................................1-22

EXERCISE 3: Define Constraints ....................................................................................1-23

EXERCISE 4: Define Loads ............................................................................................1-24

EXERCISE 5: Idealize the Model ....................................................................................1-27

EXERCISE 6: Define and Run a Static Analysis .............................................................1-29

EXERCISE 7: Display and Interpret the Results..............................................................1-32

EXERCISE 8: Defining Design Parameters Using Relations ..........................................1-37

EXERCISE 9: Investigating Parameters with Global Sensitivity Studies ........................1-42

EXERCISE 10: Design Optimization...............................................................................1-46

MODULE SUMMARY ................................................................................................... 1-53

SIMPLIFYING MODELS WITH IDEALIZATIONS 2-1

IDEALIZATIONS ............................................................................................................. 2-2

Using Shell Idealizations....................................................................................................2-2

Using Solid Model Idealizations ........................................................................................2-4


Creating Rigid Connections ............................................................................................... 2-4

Creating Connections......................................................................................................... 2-5

LABORATORY PRACTICAL..........................................................................................2-6

EXERCISE 1: Using Mass, Spring, and Beam Idealizations............................................. 2-7

EXERCISE 2: Using Shell Idealizations ......................................................................... 2-12

EXERCISE 3: Using Solid Idealizations ......................................................................... 2-18

EXERCISE 4: Using Rigid Connections ......................................................................... 2-27

EXERCISE 5: Using End and Perimeter Welds .............................................................. 2-29

MODULE SUMMARY....................................................................................................2-36

OPTIMIZING MODELS FOR ANALYSIS 3-1

INTEGRATED MODE MODELING ................................................................................3-2

Solid Modeling................................................................................................................... 3-2

Modeling Shells ................................................................................................................. 3-2

Creating Regions................................................................................................................ 3-5

Structural Assemblies ........................................................................................................ 3-6

Modeling in 2-D................................................................................................................. 3-8

LABORATORY PRACTICAL........................................................................................3-10

EXERCISE 1: Suppressing Structurally Insignificant Features....................................... 3-11

EXERCISE 3: Shell Modeling Using Auto Detect .......................................................... 3-21

EXERCISE 4: Creating Regions...................................................................................... 3-23

EXERCISE 5: Creating Volume Regions........................................................................ 3-28

Exercise 6: Structural Assemblies.................................................................................... 3-30

EXERCISE 7: Modeling a 2-D Plane Stress Plate........................................................... 3-32

MODULE SUMMARY....................................................................................................3-34

ASSIGNING MATERIAL PROPERTIES 4-1

BASIC MECHANICS OF MATERIALS ..........................................................................4-2

Young's Modulus ............................................................................................................... 4-2

Poisson's Ratio ................................................................................................................... 4-3

Systems of Units .................................................................................................................4-4


EXERCISE 1: Assign Structural and Thermal Material Properties ................................... 4-5

EXERCISE 2: Adding New Materials to the Library ........................................................ 4-7

EXERCISE 3: Edit and Delete Materials........................................................................... 4-8

MODULE SUMMARY....................................................................................................4-10

APPLYING CONSTRAINTS 5-1

INTRODUCTION ..............................................................................................................5-2


LABORATORY PRACTICAL ......................................................................................... 5-8

EXERCISE 1: Using Fixed Edge Constraints ....................................................................5-8

EXERCISE 2: Using Point Constraints............................................................................5-10

EXERCISE 3: Using Surface Constraints ........................................................................5-14

EXERCISE 4: Constraining Shell Models .......................................................................5-15

EXERCISE 5: Using Coordinate System Constraints ......................................................5-17

EXERCISE 6: Using Cyclic Symmetry Constraints ........................................................5-19

MODULE SUMMARY ................................................................................................... 5-21

SIMULATING APPLIED LOADS 6-1

INTRODUCTION.............................................................................................................. 6-2


EXERCISE1: Applying General Loads..............................................................................6-4

EXERCISE 2: Applying Spatial Load Variations ..............................................................6-8

EXERCISE 3: Varying Load Direction and Magnitude...................................................6-13

EXERCISE 4: Using Pressure and Gravity Loads ...........................................................6-15

EXERCISE 5: Creating Load Distributions .....................................................................6-19

MODULE SUMMARY ................................................................................................... 6-22

RUNNING AND EVALUATING ANALYSES 7-1

INTRODUCTION.............................................................................................................. 7-2

Analysis Options ................................................................................................................7-2


EXERCISE 1: Running a Structural Analysis....................................................................7-4

EXERCISE 2: Defining Thermal Analyses......................................................................7-18

EXERCISE 3: Running Combined Analyses ...................................................................7-21

EXERCISE 4: Combining Loads in Results ....................................................................7-25

EXERCISE 5: Comparing MPA to SPA..........................................................................7-29

MODULE SUMMARY ................................................................................................... 7-32

ANALYSIS AND RESULTS: EXAMPLES 8-1

INTRODUCTION.............................................................................................................. 8-2

Analyzing Models ..............................................................................................................8-2


EXERCISE 1: Analyzing Roller Mill Bearing Mechanical Properties ..............................8-4

EXERCISE 2: Analyzing Frying Pan Thermal Properties ...............................................8-12

EXERCISE 3: Analyzing a Tuning Fork..........................................................................8-21

MODULE SUMMARY ................................................................................................... 8-25


RUNNING SENSITIVITY AND OPTIMIZATION STUDIES 9-1

INTRODUCTION ..............................................................................................................9-2

Running Global Sensitivity Studies ................................................................................... 9-2

Running Local Sensitivity Studies ..................................................................................... 9-2

Running Optimizations ...................................................................................................... 9-3


EXERCISE 1: Optimizing a Belt Clip ............................................................................... 9-5

EXERCISE 2: Running Sensitivity Studies ..................................................................... 9-15

EXERCISE 3: Optimizing the Clip.................................................................................. 9-21

MODULE SUMMARY....................................................................................................9-25

RUNNING ANALYSES 10-1

Model Description ............................................................................................................10-2

ADVANCED EXERCISES 11-1

INTEGRATED MODE CONTACT FUNCTIONALITY ...............................................11-2

Running Contact Analyses............................................................................................... 11-2

Defining Contact Regions ................................................................................................ 11-3

Defining Contact Analysis Measures............................................................................... 11-3

Setting Contact Analysis Options .................................................................................... 11-4

TRANSIENT THERMAL ANALYSIS ...........................................................................11-5

Fundamentals ................................................................................................................... 11-5


EXERCISE 1: Creating and Analyzing Spot Welded Sub-Assemblies ........................... 11-9

EXERCISE 2: Contact Problems ................................................................................... 11-14

EXERCISE 3: Running Transient Thermal Analyses.................................................... 11-21

EXERCISE 4: Analyzing Large Deformation ............................................................... 11-26

MODULE SUMMARY..................................................................................................11-36

FATIGUE ADVISOR 12-1

OVERVIEW .....................................................................................................................12-2


EXERCISE 1: Piston Fatigue........................................................................................... 12-4

MODULE SUMMARY..................................................................................................12-11

STUDENT PROJECTS 13-1

STUDENT PROJECTS ....................................................................................................13-2

Designing a Flagpole ....................................................................................................... 13-2

Designing a Driveshaft..................................................................................................... 13-3


Designing a Wing Spar.....................................................................................................13-3

Designing a Valve Housing..............................................................................................13-5

Designing a Heat Sink ......................................................................................................13-7

Analyzing a Buckling Ring ..............................................................................................13-8

Analyzing a Beverage Can ...............................................................................................13-9

STUDENT PROJECT HINTS....................................................................................... 13-12

USING PTC HELP A-1

DEFINING THE PTC HELP FEATURES....................................................................... A-2

USING THE Pro/ENGINEER ONLINE HELP................................................................ A-2

Defining the PTC Help Table of Contents ........................................................................A-8

TECHNICAL SUPPORT B-1

Locating the Technical Support Web Page ....................................................................... B-2

Opening Technical Support Calls via E-Mail.................................................................... B-2

Opening Technical Support Calls via Telephone .............................................................. B-3

Opening Technical Support Calls via the Web.................................................................. B-3

Sending Data Files to PTC Technical Support .................................................................. B-3

Routing Your Technical Support Calls.............................................................................. B-4

Technical Support Call Priorities ...................................................................................... B-5

Software Performance Report Priorities............................................................................ B-5

Registering for On-Line Support....................................................................................... B-5

Using the Online Services ................................................................................................. B-6

Finding Answers in the Knowledge Base.......................................................................... B-7

CONTACT INFORMATION ........................................................................................... B-9

Technical Support Worldwide Electronic Services ........................................................... B-9

Technical Support Customer Feedback Line..................................................................... B-9

TELEPHONE AND FAX INFORMATION .................................................................. B-10

North America Telephone Information ........................................................................... B-10

Europe Telephone Information........................................................................................ B-11

Asia and Pacific Rim Telephone Information ................................................................. B-15

ELECTRONIC SERVICES ............................................................................................ B-18


1

Module

Introduction to Pro/MECHANICAIn this module, you learn the basic Pro/MECHANICA structural

simulation process.

Objectives

After completing this module, you will be able to:

• Create a Pro/ENGINEER model for simulation purpose.

• Setup the model for static analysis, including defining the modelidealization, constraints, loads and material properties.

• Define and run the analysis.

• View and interpret the result.

• Optimization the design.


2 Fundamenta ls o f Pro /MECHANICA

NOTES

OVERVIEW

Structure Simulation

An important phase of most design cycles requires engineers to measure

the stress and displacement distribution of new designs. This is necessary

in order to validate the design and ensure it is suitable for its intended use.

To further improve the design, engineers may also need to ascertain the

key variables that control the design. This information is usually used to

optimize designs.

Pro/MECHANICA enables you to validate and optimize your designs by

simulating their responses to various structural load types. Depending on

the purpose of the simulation, the process may vary.

There are two simulation process types:

• Integrated mode – Pro/ENGINEER with integrated limitedPro/MECHANICA analysis features.

• Independent mode – Stand along Pro/MECHANICA withcomprehensive analysis features.

In the Integrated mode, a typical structural simulation consists of the

design validation and optimization phases. These consist of twelve steps.

The first eight steps comprise the Design Validation phase:

1. Create the Model Create the part or assembly that satisfies the

design intent.

2. Idealize the Model Prepare the model for automatic mesh

generation. This includes specifying appropriate idealization types

and any required idealization properties.

3. Set Units and Material Properties Specify the appropriate system

of units and assign material properties.

4. Identify Constraints Define realistic constraints that simulate

how the model will function in the real world.

5. Set Loads Define loads to simulate how the model is loaded in

the real world.


In t roduct ion to Pro /MECHANICA Page 1-3

NOTES

6. Define the Analysis Define the appropriate analysis type (static,

modal, and so on) based on the required results. You can alsodefine the convergence settings.

7. Run the Analysis Run the defined analysis.

8. View and Interpret the Results You can generate graphs, fringe

plots, and so on to visualize the converged results.

The last four steps comprise the Design Optimization phase:

9. Define the Design Parameters Create Pro/MECHANICA

parameters that specify how the model geometry can change.

10. Run Sensitivity Studies Perform sensitivity studies on the

parameters defined in the previous step. This will help you decide

which parameters have the most influence on the design.

11. Run the Optimization Specify a goal, design constraints, and

parameter ranges that constrain the solution boundaries.

12. Update the Model You can automatically or manually update the

Pro/ENGINEER model.



NOTES

RUNNING ANALYSES

This example illustrates a typical structural simulation process as run in

the Integrated mode.

Analysis Design Scenario

Imagine you are an engineer designing large, industrial shelving systems.

These systems are intended for warehouses and must support large loads.

You will use Pro/MECHANICA to model and improve an existing bracket

design. The bracket is used to connect the shelves to the vertical support

rails.

Figure 1 Designing a shelving bracket

Identifying the Design Requirements

The objective is to find a design that is stronger and lighter than the

existing system, yet still easy to assemble. This results in the following

design requirements.

Objective

The design objective is to minimize the bracket mass.

Criteria

The design must support a 20 lbs. (pounds) load applied at a specific

point. The following design criteria must be satisfied:



NOTES

• The maximum stress is less 93 N/mm2 (MPa). This maximum

allowable stress is calculated using the tensile yield strength of the

available steel (231 N/mm2) with a safety factor of 2.5.

• The maximum allowable displacement is 0.04 mm. This is necessarybecause a small deformation in the bracket can cause large

displacement at the end of the rack it carries.

• The distance between the two bolt holes (30 mm) and sheet metalthickness (2.5 mm ) must remain fixed. This is necessary due to

assembly constraints.

Creating the Bracket Design

The bracket design is created using Pro/ENGINEER. When constructing

the model, the dimension scheme should reflect the design intent, and also

provide enough design parameters for the design optimization. The

following figure shows the desired design parameters.

Figure 2 Bracket design parameters.

Due to this consideration, the bracket is created using the specific

dimensioning scheme shown in the following figure.



NOTES

Note:

Relations can be used to capture the inter-relationship among

the dimensions.

Figure 3: The bracket dimensioning scheme.

Note that the four rounds are created as two separate features: the inner

and outer rounds. This dimensioning scheme provides the flexibility of

altering each feature independently to improve the design.

According to the design constraint, the dimensions of the hole will remain

fixed during the optimization. The detailed instructions can be found in

Exercise 1.

Model Idealization

Like other FEA and GEA simulation packages, Pro/MECHANICA

performs computation at the individual elements. Because

Pro/MECHANICA has extensive auto-meshing capability, most of the

element generation is transparent.

The only required step is to idealize the model. The AutoGEM will

generate the appropriate element based on the model idealization. Various

types of model idealization are available in Pro/MECHANICA to capture

the characteristics of the model. For example, the default solid idealization



NOTES

is perfect for simulating “chunky geometry,” and the shell idealization is

suitable for “thin geometry,” such as the bracket.

Idealizing the Bracket as a Shell

To define a shell, you need to define the surface pairs. In this example, the

front and back surface of the bracket model are defined as a surface pair.

The surface pair will be compressed to form the mid-surface, as shown in

the following figure. The detailed instructions can be found in Exercise 5.

Figure 4 Mid-surface compression.

Defining Material Properties

The material of the bracket is steel. The material properties are assigned to

the bracket using the available properties in the library. The detailed

instructions can be found in Exercise 2.

Defining Constraints

In reality, the top and bottom surface of the bracket are welded to other

components. As a result, these surfaces need to be rigidly fixed in

Pro/MECHANICA so that no movement is allowed. The following figure

shows the constrained bracket model. The detailed instructions can be

found in Exercise 3.



NOTES

Figure 5 Constrain the bracket surfaces

Defining Loads

In this example, the bracket load must be calculated using realistic loading

condition. In reality, a rack is attached to the bracket using two bolts. A 20

lbs. load is applied to a point as shown in the following figure.

Load

Figure 6 The rack assembly.

Calculating the Bracket Bearing Load

A Free Body Diagram (FBD) can be created as shown in the next figure.

Ay

Ax

By

Bx20 lbs (88.9 N)

Figure 7 The Free Body Diagram of the rack.



NOTES

Since the system of equations is indeterminate, the assumption Ay = By is

made. The static calculation yields the following result:

Ax = -889 N; Ay = 44.5 N; Bx = 889 N; By = 44.5 N

The force components of the bracket bearing load are equal and opposite.

The detailed instructions can be found in Exercise 4.

Running the Analysis

The analysis type needs to be chosen depending on the type of problem.

For this problem, a single pass adaptive static analysis is used. The

summary file is used to monitor the progress of the analysis. The detailed

instructions can be found in Exercise 6.

Displaying and Interpreting the Results

The result windows are created to show the stress and displacement of the

model. In this example, three result windows are created:

• An animated fringe plot that shows the von Mises stress of the model.

• An animated fringe plot that shows the displacement of the model.

• An animated fringe plot that shows the principal stress of the model.

• A fringe plot used to dynamically query the stress of the model.

The results show that the design needs to be improved to satisfy the design

requirements. Since most of the part had very low stress, this part is over-

designed. This indicates that further improvement can be made to reduce

weight. The detailed instructions can be found in Exercise 7.

Creating the Design Parameters

Design parameters are variables of the model that can potentially affect

the design objectives. Design parameters can be Pro/ENGINNER

dimensions or model parameters.

In a design optimization, the system changes the variables within a certain

range to find the best values that satisfy the constraints and optimize the

design goal. In this example, there are eight design parameters.



NOTES

Maintaining Design Intent using Relations

In Pro/ENGINEER, relations can be created to capture the inter-

relationship among parameters and dimensions.

In Pro/MECHANICA Integrated mode, these relations stay valid and

active in the simulation process. Whenever a design parameter is changed,

the system will re-evaluate the relations and regenerate the model. This

ensure that the model satisfies the design intent.

In this example, the basic shape of the model should be maintained. When

varying the dimension ANG within the allowable range (from 45 degrees

to 90 degrees), the dimension TOP should be adjusted accordingly. To

capture this design intent a relation was created:

top = 62.5 + (45-ang) * 0.5

Due to this relation, when changing the dimension TOP from 45 to 90

degrees, the bracket model maintains its basic shape, as shown in the

following figure.

In Exercise 8, the relation is used to maintain design intent during a

sensitivity study. As a result, eight independent design parameters are

reduced to seven.

Figure 8 Maintain the basic shape of the bracket using relations.

Running Sensitivity Studies

Sensitivity studies are used to determine whether a certain characteristic or

property of the model is sensitive to a design parameter. Specifically, the

system calculates the changes in your model's measures (such as stress and

displacement) when you vary a parameter over a specified range.



NOTES

Sensitivity studies can be performed by varying the parameters within a

range (Global sensitivity), or at a specific value (local sensitivity).

Global sensitivity studies serve two primary purposes:

• To rule out the unimportant parameters in the upcoming optimization.

• To determine a good initial value for that parameter to use in theoptimization.

Running Optimization Studies

In an optimization study, the system try to find a set of design parameter

values within the specified ranges that satisfy all of the imposed

constraints, at the same time, try to maximize/minimize certain properties

of the model.

There are several key elements that need to be defined in an optimization

study.

• Goal: A goal is a certain property of the model that will bemaximized/minimized in an optimization analysis.

In this case, the goal is to minimize the mass of the bracket.

• Optimization Constraints: They are constraints that model parametersneed to satisfy.

In this case, the constraints are:

� The maximum von Mises stress is less 93 N/mm2 (MPa).

� The maximum allowable displacement is 0.04 mm.

• Optimization Variables: In an optimization study, the system changesthe variables within a certain range to find the best values that satisfy

the constraints and optimize the goal.

In this case, there are 7 variables shown in Figure 2. The ranges for

these variables can be found in Exercise 10.

Reviewing Optimization Results

The types of results you may want to review are the plots showing von

Mises stress compared to optimization pass. You may also want to review

total mass compared to optimization pass



NOTES

USER INTERFACE: INTEGRATED MODE I

In the Integrated mode, there are four ways for you to access the

Pro/MECHANICA commands:

• Commands located under the MECHANICA menu

• Icons in the toolbar located on the right of the graphic pane

• Object sensitive shortcut menu in the MODEL TREE

• Object sensitive shortcut menu accessed from graphic window

Using the MECHANICA Menu

Using Pro/MECHANICA, the user can perform simulation by navigating

the menu structures.

Using Toolbar Icons

You can perform Pro/MECHANICA tasks using icons located on right of

the graphic pane.

The following tables list some commonly used icons.

Table 1 Structural Load Icons

Icon Description

Create a point load.

Create an edge/curve load.

Create a surface load.

Create a centrifugal load.

Create a pressure load.

Create a gravity load.

Table 2 Structural Constraint Icons

Icon Description

Create a point constraint.

Create an edge/curve constraint.

Create a surface constraint.

Create a cyclic symmetry constraint.



NOTES

Table 3 Structural Idealization Icons

Icon Description

Define a beam idealization.

Define a shell idealization.

Define a mass idealization.

Define a spring idealization.

Accessing the Object Sensitive Menu from theMODEL TREE

The MODEL TREE displays the entities exist in a simulation model,

including the Simulation Features, Idealizations and Loads/Constraints,

etc.

Figure 9 A typical top-level model tree.

You can expend the junction box to display the detailed list of the entities.

Figure 10 Navigate the Pro/MECHANICA model tree.

Selecting an entity in the MODEL TREE will highlight the entity in the

graphic pane. After an entity is selected in the MODEL TREE, you can



NOTES

access the object sensitive shortcut commands by clicking the right mouse

button. The available commands are limited to the selected entity type.

Figure 11 Access the object sensitive menu from the MODEL TREE.

The SELECT_ACTION paradigm streamlines the workflow, increases the

productivity.

Using the Icons in the Graphic Window

Object-sensitive shortcut menu can also be accessed by right-clicking the

icons from the graphic window.

Figure 12 Using the shortcut menu in the graphic window.



NOTES

LABORATORY PRACTICAL

Goal

Create a bracket model using Pro/ENGINEER. Set up a static structural

analysis to simulate a loaded bracket. Optimize the bracket design.

EXERCISE 1: Create the Bracket Design

Figure 13 The finished bracket part.

Task 1. Create a new part called BRACKET.

1. Set your working directory to the folder that corresponds to the

name of the current module.

2. Set the environment settings. Click Utilities > Environment. Clear

the Ring Message Bell and Spin Center check boxes. Click OK

to close the dialog-box.

3. Create a new part model:

� Click [New file].

� Select Part.

� Enter [bracket ] as the name.

� Accept the default Use default template.

� Click OK.



NOTES

Note:

In Pro/ENGINEER, the models created using the default

templates will contain the information in the template model,

such as the default datum planes and coordinate system.

4. Set up the units.

� From the PART menu. Click Set Up > Units. Select

millimeter Newton Second(mmNs) . Click Set.

� Accept the default Convert Existing Numbers (Same Size).

� Click OK, followed by Close.

Task 2. Create an extruded protrusion as the base feature.

1. From the INSERT pull down menu, click Protrusion > Extrude >

One Side > Done.

2. Select the FRONT datum plane and click OK.

3. Select TOP from the Sket View menu and slect the TOP datum

plane.

4. The system uses the system default feature creation options and

enters the sketcher mode. Close the REFERENCE dialog box.

5. Sketch the section of the base feature as shown in the following

figure.

Note:

The dimensioning scheme captures the design intent, and

provides flexibility for design optimization.



NOTES

Figure 14 The base protrusion section.

6. Click [Done] when finish. The system extrudes a defaultdepth and displays the depth value.

7. Select Done.

8. Modify the depth. Double-click the depth dimension and enter

[2.5 ]. Click OK.

9. Switch to the default view. Click View > Default Orientation. The

model should look like the following figure.

10. Save the model.



NOTES

Figure 15 The base protrusion.

Task 3. Create one round on the two inner edges shown in the following

figure. The round will have the radius of 5 mm.

Figure 16 Create one round on the two inner edges.

1. Click the [Select Geometry] icon.

2. Select one inner edge. Press <Shift> and select the other edge. You

may need to switch to hidden line mode to see the edges.

3. From the INSERT pull down menu, click Round.

4. A round is created with a temporary value, as shown in the

following figure. You can use the drag handle to dynamically

adjust the round size.



NOTES

5. Double click the dimension value. Enter [5].

6. Click the background to implement the changes.

Tips & Techniques

In Pro/ENGINEER to spin, zoom, or pan the model; Press

<CTRL> key and use the three mouse buttons.

Task 4. Create another round on the outer edges, as shown in the

following figure.

Figure 17 Create one round on the outer edges.



NOTES

1. Use the same procedures in the previous task to create one round

on the two outer edges.

2. Enter [5] as the round radius.

Task 5. Create and dimension the two bracket holes.

1. From the INSERT pull down menu, click Hole. Accept the default

Straight hole HOLE TYPE option.

2. Enter [12.5 ] for the diameter.

3. Select Thru All for the DEPTH ONE drop down list.

4. Define the hole placement:

� Select the front bracket surface as the PRIMARY REFERENCE.

� Accept the default Linear PLACEMENT TYPE option.

� Select RIGHT and TOP datum plane as the LINEAR

REFERENCE.

� Enter [12.5 ] as the distance from the RIGHT datum plane.

� Enter [0] as the distance from the TOP datum plane.

5. Preview and close the HOLE dialog box by clicking [Done].The hole should appear as shown in the following.

Figure 18 Place a linear hole.

Task 6. Create the second hole as an identical pattern

1. Click Feature > Pattern from the PART menu.



NOTES

2. Select the hole you just created as the feature to be patterned.

3. Click Identical > Done.

4. Pick the 0.0 locating dimension as the pattern dimension for the

first direction.

5. Enter [30] for the dimension increment.

6. Click Done from the EXIT menu.

7. Enter [2] for the number of instances.

8. Click Done from the EXIT menu.

9. Save the model. Click [Save]. The model should appear as

the figure shown in the beginning of this exercise.



NOTES

EXERCISE 2: Assign the Material Properties

Task 1. Enter Pro/MECHANICA Structure Integrated mode.

1. From the APPLICATIONS pull down menu, click Mechanica.

Click Continue in the UNIT INFO dialog box to confirm your

system of units.

2. Click Structure from the MECHANICA menu.

Task 2. Specify the material properties of the bracket. You will define

the part as steel.

1. Assign the material steel to the bracket. Click Model > Materials.

2. Select STEEL and from MATERIALS IN LIBRARY list, add it to

the MATERIALS IN MODEL list.

3. Select Part From the Assign drop-down list.

4. Select the bracket part and click Done Sel.

5. Close the MATERIALS dialog box.



NOTES

EXERCISE 3: Define Constraints

Task 1. Define how the part is constrained. In reality, the bracket is

attached by welding the top and bottom edges to the adjoining hardware.

1. Create an edge constraint. Click [Create an edge/curve

constraint].

2. In the CONSTRAINT dialog box, enter [weld ] as the name of the

constraint.

3. Assign the constraint to a new constraint set.

� In the CONSTRAINT dialog box, click New next to the

MEMBER OF SET to bring up the CONSTRAINT SET dialog

box.

� In the CONSTRAINT SET dialog box, enter [weld ] as the

Constraint set name.

� Click OK to close the CONSTRAINT SET dialog-box.

4. Click the [Select] under the CURVE(S).

5. Select the front top edge and front bottom edge. Click Done Sel.

6. Fix all the DOFs (Degrees of Freedom).

7. Click OK to close the CONSTRAINT dialog-box. The constraint

symbols appear on the model as shown in the following figure.

Figure 19 Constraint the bracket.



NOTES

EXERCISE 4: Define Loads

Task 1. Apply the bearing load on the top hole.

1. Create the bearing load. Click [Bearing load].

2. In the BEARING LOAD dialog box, enter [bearing_top ] as the

load name.

3. Assign the load to a new load set.

� In the BEARING LOAD dialog box, click New to bring up the

LOAD SET dialog box.

� In the LOAD SET dialog box, enter [bearing_load ] as the

load set name.

� Click OK to close the LOAD SET dialog box.

4. In the BEARING LOAD dialog box, click [Select] under the

HOLE(S). Select the front bottom edge of the top hole. Click Done

Sel to finish.

Note:

In this case, just like the constraint, the bearing load can beapplied to the surface of the hole.

5. Accept the default option Components from the FORCE drop

down list.

6. Enter [889 ] for the X component, enter [-44.5 ] for the Y

component, keep Z as zero.

7. Click Preview. The system displays the load's distribution, as

shown in the following figure.



NOTES

Figure 20 Preview the bearing load.

8. Click OK to finish.

Task 2. Apply the bearing load on the bottom hole.

1. Create another bearing load. Click [Bearing load].

2. In the BEARING LOAD dialog box, enter [bearing_bottom ] as

the load name.

3. Accept the default load set.

4. In the BEARING LOAD dialog box, click [Select] under the

HOLE(S). Select the front bottom edge of the lower hole. Click

Done Sel to finish.

5. Accept the default option Components from the FORCE drop

down list.

6. Enter [-889 ] for the X component, enter [-44.5 ] for the Y

component, keep Z as zero.

7. Click Preview to see the load's distribution.

8. Click OK to finish. The model should appear as shown in the

following figure.



NOTES

Figure 21 Apply the bearing load on both holes.

9. Click Done/Return from the LOADS menu.



NOTES

EXERCISE 5: Idealize the Model

Task 1. Idealize the model as a shell.

1. Select the model.

2. From the STRC MODEL menu, click Idealizations > Shells >

Midsurfaces > New > Constant.

3. Select the front surface of the model.

4. Click Query Sel and select the back surface.

5. Click Done Sel to finish. Pro/MECHANICA highlights the pairs

in red and yellow.

Task 2. Verify the idealization and visualized the compressed model.

1. Test the mid-surface compression. Click Compress > Shells

only.

2. Click Show Compress to see the created shell. The system

displays only the mid-plane geometry, as shown in the following

figure (displayed in yellow)

Figure 22 The compressed bracket mid-surface.



NOTES

Note:

The AutoGEM functionality uses the surface to create

triangular and quadrilateral shell elements. They can be

visualized in the Independent mode.

3. Click Show Original to view the original part (displayed in green).

4. Click Show Both to display both the original part and the

midsurface.

5. Click Done > Done Return > Done Return to finish.



NOTES

EXERCISE 6: Define and Run a Static Analysis

Task 1. Define a structural static analysis to determine the stress and

strain caused by the applied loads.

1. Click Analyses from the MEC STRUCT menu to bring up the

ANALYSES dialog box.

2. Create a new static analysis:

� Accept the default Static from m the NEW ANALYSIS type

drop down list.

� Click New. The STATIC ANALYSIS DEFINITION dialog box

appears.

3. In the STATIC ANALYSIS DEFINITION dialog box,

� Enter [bracket_static ] for the name.

� Select weld for the Constraint Set.

� Select bearing_load for the Load Set. Unselect other load set

as necessary.

� On Convergence tab, accept the default Single-Pass

Adaptive.

� Click on the Output tab. Change Plotting Grid to 7.

� Click OK to close the STATIC ANALYSIS DEFINITION dialog-

box.

4. Close the ANALYSES dialog box.

5. Verify that Pro/MECHANICA treat your model as a shell model.

� From the MEC STRUCT menu, click Done/Return.

� From the MECHANICA menu, click Settings and verify that

Use Pairs is checked.

Note:

If you were to clear the Use Pairs check box,

Pro/MECHANICA would treat your model as a solid, which

will take longer to analysis. This setting is automatically

checked when you define pairs.



NOTES

Task 2. Run the defined analysis.

1. Click Structure > Run. The RUN dialog box appears.

2. Verify that the analysis BRACKET_STATIC is selected.

3. Click Start.

4. Click Yes when asked "Do you want error detection?".

Note:

Before starting the analysis, it is always helpful to have

Pro/MECHANICA perform error checking on your model.

Task 3. Check to see how the run is progressing by monitoring the

summary file. This file shows you details about each solver pass as the run

progresses.

1. Click Summary. A summary window appears, displaying the

report of the analysis run.

2. Scroll down a little. The report shows the following information:

� Principal System of Units.

� Model type and geometry information.

� Element information.

3. Scroll down a little further the report shows that the solver makes 2

passes.

� In the first pass all of the edges are set to p=3, which is usually

referred to as third order polynomial.

� Based on the results of this pass, the final edge order for all the

edges is determined between three and nine. This polynomial

order distribution is applied to the model and a second pass is

performed.

� Jot down the polynomial order of the second pass __________.

4. Scroll down a little further and review the error estimate. Jot down

the value _______________.

5. Scroll down a little further. The report shows the constraint set and

load set information. Check the values for the total load in X, Y

and Z directions.



NOTES

6. Scroll down a little further and review the values of the measures.

Some measures of interest may be the max displacements and

stress components.

Note:

These values can be graphically displayed using the result

interface.

7. Review the Memory and Disk Usage information. You can also

find run time in this section.

8. At the end of the report, it indicates that the run is completed.

9. Click Close to exit the Summary window. Click Done to exit the

RUN dialog box.



NOTES

EXERCISE 7: Display and Interpret the Results

Task 1. Create a RESULTS window to look at the distribution of von

Mises stress in the model.

1. Create a RESULT window. Click Results from the MEC STRUCT

menu.

2. Click No when prompted whether you want to save the model. The

result interface is displayed.

3. Create a window to display the stress.

� Click [Insert result window].

� Enter [Bracket_Max_VM ] as the name. The DESIGN STUDY

dialog box appears

� Click the bracket_static\ in the CURRENT DIRECTORY.

� Click Accept to finish.

4. Define the result window contents. In the DEFINE CONTENTS

FOR RESULT WINDOW “MAX_PRINCIPAL” dialog box,

� For the Title, enter [Maximum von Mises ].

� For Quantity, select Stress > Total > Von Mises.

� For Display, select Fringe and clear the Continuous Tone and

Average.

� Select Deform. Accept the Deformed scale 10%.

� Select Animate. Change the number of frames to 16 .

Note:

More frames will result in smoother animation and take longerto generate.

� Select Auto Start and Repeat.

� The dialog box should look like the following figure.



NOTES

Figure 23 The stress result window definition dialog box.

5. Click Accept and Show to finish the definition and display the

result window.

6. Use following icons to control the result animation:

� [Stop]; [Play] [Single Step]; [Single Step

Back]

7. Stop the animation when finish.

Task 2. Create a result window to display the displacement by copying

the existing window.

1. Click [Copy window].

2. Enter [Bracket_Displacement ] as the name.

3. Fill out the dialog-box as shown in the following figure.



NOTES

Figure 24 The displacement result window definition dialog box.

4. Click Accept to finish.

Task 3. Create a result window to display the Maximum Principal

Stresses by copying the existing window. Maximum Principal Stress

distinguishes tension from compression.


2. Enter [Bracket_Principal ] as the name.

3. Enter [Maximum Principal ] as the title.

4. Select Max Principal from the drop-down list.

5. Keep other default settings. Click Accept to finish.



NOTES

Task 4. Create a Dynamic Query result window to further investigate

the results.


2. Enter [Bracket_vm_query ] as the name.

3. Enter [Von Mises Query ] as the title.

4. Unselect the Animate check box.

5. Keep other default settings. Click Accept to finish.

Task 5. Display the result windows and examine the results.

1. Click [Display Result Windows].

2. In the display result window dialog box, click [Select all],

followed by OK. The system starts to animate all animated

windows.

3. Control individual window separately. Click one window to

activate it. The borders of selected windows should be highlighted

in yellow. Single step the animation.

4. Control multiple windows simultaneously. Press <Shift> and click

all the animated windows.

Note:

Red border indicates an inactivated window.

Task 6. Interpret the result.

1. Jot down the following observations made in the MAX VON

MISES window:

� Locations of the high von Mises stress ____________;

2. Jot down the following observations made in the BRACKET

DISPLACEMENT window:

� Maximum displacement ____________;

� Location of the maximum displacement ____________;



NOTES

� Does it satisfy the design requirement? _____________.

3. Stop the animation in all windows. Activate the VON MISES

QUERY window.

4. Determine the von Mises stress and at any point on the model.

� Click Info > Dynamic Query. The QUERY dialog box appears.

� Move the mouse cursor over the fringe plot. Notice that in the

dialog box, the value dynamically updates to show the stress

level at the mouse location.

� Click a location of your interest to place a query tag.

� Click Done to close the QUERY dialog box.

5. Determine the maximum von Mises stress and its location.

� Click Info > Model Max to display the maximum stress

location on the model. Jot down the value ____________.

6. Clear all query tags.

� Click Info > Clear All Query Tags.

� Click Yes when prompted “Do you really want to clear all the

values? ”.

7. Exit the result interface when you finish reviewing the result,

� Click File > Exit Results.

� Choose Yes when prompted to save the result window.

� Enter [Original ] for the name.




NOTES

EXERCISE 8: Defining Design Parameters UsingRelations

Task 1. Rename the dimensions in Pro/ENGINEER.

1. Return to Pro/ENGINEER. Click Applications > Standard.

2. Display the dimensions. Click Modify and pick on the base feature.

3. Rename the dimensions. From the MODIFY menu, click

DimCosmetics > Symbol.

4. Click the 45 degrees angular dimension, enter [ang ] as the name.

5. Click the 62.5 dimension from TOP datum plane to the tip of the

nose, enter [top ] as the name.

6. Click Info > Switch Dimensions to toggle dimension between the

symbolic name and numerical value. The model should look like

the following figure.

Figure 25 Rename two dimensions

Note:

The initial dimension names may be different due to differentorder of dimension creation.



NOTES

Task 2. Create a relation. As the angle changes, the bracket tip must

rotate to maintain the desired part shape. Create a relation that captures

this design intent.

1. From the PART menu, click Relations > Add.

2. Enter the following relations in the message input window:

� Enter [if ang >= 45 & ang <= 90 ]

� Enter [top = 62.5 + (45-ang) * 0.5 ]

� Enter [endif ]

� Click <Return> at a blank line to finish.

3. Pro/ENGINEER creates a file that contains the relations you

entered. To display the file and make any corrections, click Edit

Rel. To close the text editor, click File > Exit.

Note:

The text editor may be different on different platform. You canchange the text editor in the configuration file.

4. Test the relations.

� Click Modify from PART menu and select the base feature.

� Select the 45 degree angular dimension.

� Enter [90] in the message window.

� Click Regenerate from the PART menu. The model should

look like the following figure.

5. Modify the angle back to 45 degrees and regenerate the model.



NOTES

Figure 26 Test the relation by modifying the angle.

Task 3. Define the design parameters in Pro/MECHANICA. First, you

add a design parameter to vary the size of the inner fillets.

1. Click Applications > Mechanica > Dsgn Controls > Design

Params > Create. The DESIGN PARAMETERS DEFINITION

dialog box appears.

2. Click Create. The DESIGN PARAMETERS DEFINITION dialog

box appears.

3. In the DESIGN PARAMETERS DEFINITION dialog box:

� Accept the default type Dimension.

� Click Select. Pick on one of the inner round in the model, the

radius dimension with a value of 5 should appear.

� Click the radius dimension.

� Enter [inner_fillets ] for the name of the parameter and

any description you like.

� Define the range. Enter [2.5 ] for the minimum, and [12.5 ] for

the maximum.

4. Click Accept > Done to finish.

5. Test this single design variable. Click Shape Animate from the

DSGN CONTROLS menu.

6. In the shape animate dialog box:

� The inner_fillets check-box is selected by default.

� Change the NUMBER OF INTERVALS to 2.

� Click Animate.

� Press <RETURN> to continue to the next animation step. The

model should change its shape as shown in the following

figure.



NOTES

Figure 27 Define a design parameter for the inner round.

7. Click Yes to the message, “Do you want to restore the model to its

original shape? ”.

Task 4. Define more design parameters and animate the shape.

1. Using the procedures in the previous task, create more design

parameters shown in the Figure 2 at the beginning of this chapter.

The name and range of the design parameters can be found in the

following table.

Table 4: The design parameters.

Name Min Current Max

tab_width 25.0 50.0 50.0

tab_top 53.0 62.5 62.5

tab_bottom 26.0 62.5 62.5

mid_curve 46.0 50.0 53.0

ang 45 45 90

outer_fillets 2.5 5 12.5

2. Select Done after creating the parameters.

3. From the DSGN CONTROLS menu, click Shape Animate.

4. In the SHAPE ANIMATE dialog box,

� Select all parameters.

� Change their settings as shown in the following table.

Table 5 Shape Animate settings.



NOTES

Parameter Name Settings1: Settings2:

tab_width 50.0 25.0

tab_top 62.5 53.0

tab_bottom 62.5 26.0

mid_curve 53.0 46.0

ang 45 90

inner_fillets 2.5 12.5

outer_fillets 2.5 12.5

� Enter [2] for the NUMBER OF INTERVALS.

� Click Animate.

� Press <RETURN> to continue to the next animation step. The

model should change its shape as shown in the following

figure.

Figure 28 Two design parameter settings.

Note:

Shape Animate simulates what may happen to the geometry

during sensitivity and optimization studies, as the result of

design parameters being updated. It is a good practice to use

shape animate after creating design variables to test the

validity of the geometry.

5. Click Yes to restore the model to its original shape.



NOTES

EXERCISE 9: Investigating Parameters with GlobalSensitivity Studies

Task 1. Create a global sensitivity study. Change the inner_fillets radius

within its range (2.5 to 12.5 mm). All other parameters will stay at their

current position during the run.

1. Click Structure > DesignStudies. The DESIGN STUDIES

DEFINITION dialog box appears.

2. In the DESIGN STUDIES DEFINITION dialog box:

� Enter [gs_tab ] for the Study Name.

� Select Global Sensitivity for the type of study.

� For the description, Enter [Sensitivity of the bracket to inner

fillet radius size].

� Verify that BRACKET_STATIC (STATIC) analysis is selected.

� Select INNER_FILLETS parameter and verify that the Start is

Minimum and the End is Maximum.

� Enter [4] for the number of intervals.

� Check the Repeat P-Loop Convergence. The dialog box should

appear as shown in the following figure.



NOTES

Figure 29 The DESIGN STUDIES DEFINITION dialog box.

� Click Accept to create the design study.

3. Click Done to close the DESIGN STUDIES dialog box.

Task 2. Run a global sensitivity study.

1. Click Run. The RUN dialog box appears.

2. Verify that GS_TAB (GLOBAL SENSITIVITY) is selected.

3. Reuse elements from an existing study.

� Click Settings. The RUN SETTINGS dialog box appears.

� Select Use Elements from an existing study check-box.

� Click Select and select BRACKET_STATIC.

� Click Accept to close the STUDY DIRECTORY WITH

ELEMENTS dialog box.

� Click Accept to accept and close the RUN SETTINGS dialog

box.



NOTES

4. Click Start to start running the study.

5. Click Yes for error detection.

6. Click Summary to monitor the study's progress.

7. When the study is complete, click Close > Done.

Task 3. Create a RESULTS WINDOW to graph the von Mises stress vs.

inner_fillet radius.

1. Click Results from the MEC STRUCT menu.

2. Click No when prompted to save the current model. The system

displays the result interface.


� Click [Insert Result Window].

� Enter [vm_sens ] as the name.

� Click Accept. The DESIGN STUDY dialog box appears

� Click the gs_tab\ in the CURRENT DIRECTORY.

� Click Accept to finish. The DEFINE CONTENTS FOR RESULT

WINDOW “VM_SENS” dialog box appears.


FOR RESULT WINDOW “VM_SENS” dialog box,

� For the TITLE, enter [Max von Mises Stress vs.inner_fillets radius ].

� In the QUANTITY section, click Select next to MEASURE. The

SELECT A MEASURE dialog box appears.

� Scroll down through the list of PREDEFINED measures and

select max_stress_vm from the list.

� Click Accept to return to the DEFINE CONTENTS FOR

RESULT WINDOW “VM_SENS” dialog box.

� In the LOCATION section, click Select next to DESIGN VAR.

� Select INNER_FILLETS followed by Accept.

� Click Accept and Show.



NOTES

Figure 30 Max VM stress measure vs. inner_fillets dimension graph.

Task 4. Review and interpret the results of a global sensitivity study.

1. The curve quantifies the impact that inner fillets have on stress in

your model.

2. Jot down the INNER_FILLETS value that corresponds to the stress

design constraint __________________. This value can be used as

the initial value of INNER_FILLETS in the optimization.

3. Jot down the range of INNER_FILLETS that von Mises stress is

sensitive to __________________. When there is computer

hardware constraints, this range can be used in the optimization,

instead of using the entire range.

4. Click File > Exit Results when finish.

5. Select No when prompted to save the result windows.



NOTES

EXERCISE 10: Design Optimization

Task 1. Create the optimization design study. The goal is to minimize

total mass. In addition, there are two limits. Keep the Von Mises stress

below

1. Click Design Studies from the STRUCTURE menu.

2. Click Create in the DESIGN STUDIES dialog box.

3. In the DESIGN STUDIES DEFINITION dialog box, define the name

and type:

� Enter [tab_opt ] for the study name.

� Select Optimization from the TYPE drop down list.

� For the description, Enter [Optimization study for the

bracket ].

4. Set the optimization goal. Verify that GOAL is set to Minimize and

that MEASURE is set to total_mass.

5. Define the optimization limits:

� Click Create underneath LIMITS ON MEASURES. The list of

measures appears.

� Select both max_disp_mag and max_stress_vm from the list.

These are the two limits you want the optimizer to track.

� Click Accept to return to the DESIGN STUDY DEFINITION

dialog box.

� Set the max_disp_mag limit. Accept the default < sign. Enter

[0.04 ] as the limit value.

� Set the max_stress_vm limit. Select the radio button next to

max_stress_vm. Accept the default < sign. Enter [93] as the

limit value.

6. Define the variables.

� In the PARAMETERS section, select all seven buttons under

Parameters. You can use the scroll bar in the PARAMETERS

area to display all the parameters.

� Verify that the MIN is Minimum and the MAX is Maximum for

all parameters.



NOTES

� Assign the parameters initial values. Enter the INIT value listed

in the following table

Table 6: Set the parameter range and initial values

Parameter Min Init Max

inner_fillets Minimum 3.75 Maximum

outer_fillets Minimum 3.75 Maximum

tab_width Minimum 50.00 Maximum

tab_top Minimum 62.50 Maximum

tab_bottom Minimum 62.50 Maximum

mid_curve Minimum 50.00 Maximum

ang Minimum 45 Maximum

� Enter [2] as the OPTIM CONVERGENCE (%).

� Accept the remaining default values. The dialog box should


Figure 31 Optimization design study definition dialog box.

7. Click Accept, followed by Done to finish the optimization design

study definition.



NOTES

Task 2. Using the pre-run result, create a result window to display the

graph of von Mises stress vs. Optimization pass. The graph shows how the

stress was reduced during the optimization.


2. Click No when prompted to save the current model. The system

displays the result interface.

3. Create a result window to display the graph of von Mises stress vs.

optimization pass:


� Enter [vm_history ] as the name.

� Click Accept. The DESIGN STUDY dialog box appears.

� The pre-run design study result is in the subdirectory

Fund_structure_320/Integrated/results , navigate to

the directory, select Results from the list and click Change

Directory.

� Double-click on tab, select tab_opt from the list of studies.

� Click Accept to finish. The DEFINE CONTENTS FOR RESULT

WINDOW “VM_HISTORY” dialog box appears.


FOR RESULT WINDOW “VM_ HISTORY” dialog box,

� Enter [Max Von Mises Stress vs. Optimization

Pass ] for the title.

� In the QUANTITY section, select Measure from the list.

� Click Select next to MEASURE. The SELECT A MEASURE

dialog box appears.


select max_stress_vm from the list.


RESULT WINDOW “VM_ HISTORY” dialog box.




NOTES

Task 3. Create a RESULT window to displays the graph of mass vs.

optimization pass by copying an existing window definition

1. Click [Copy window]. The COPY RESULT WINDOW:

“VM_HISTORY” appears.

1. Enter [mass_history ] as the name the new window followed by

Accept. The DEFINE CONTENTS FOR RESULT WINDOW

“MASS_HISTORY” dialog box appears.


FOR RESULT WINDOW “MASS _ HISTORY” dialog box,

� Enter [Total Mass vs. Optimization Pass ] for the

title.

� In the QUANTITY section, select Measure from the list.

� Click Select next to MEASURE. The SELECT A MEASURE

dialog box appears.


select total_mass from the list.


RESULT WINDOW “MASS _ HISTORY” dialog box.


3. Jot down the following information:

� Initial mass _______________;

� Final mass ________________.




� Enter [bracket_optimization ] for the name.



NOTES

Figure 32 The optimization graphs.

Task 4. Replay the optimization process and update the design.

1. Change the working directory to where the optimization design

study is located.

� Click File > Working Directory.

� Navigate to the RESULTS sub-directory.

� Click OK.

2. From the MEC STRUCT menu, click Model > Dsgn Controls >

Optimize Hist > Search Study.

5. Animate the optimization process.

� Select the BRACKET_OPT.

� Press <Enter> when prompted to review the next step.

� Repeat to advance to the next step.

6. Update the design parameters so that the model remains at the

optimized state. Press <Enter> when prompted “Leave the model

at the optimized shape?”. The model should look like the

following figure.



NOTES

Figure 33 The optimized bracket model.

Task 5. Create a results window to show the von Mises Stress fringe

plot of the optimized model.

1. Change the working directory back to

FUND_STRUCTURE_320/INTEGRATED.

� Click File > Working Directory.

� Navigate to the FUND_STRUCTURE_320/INTEGRATED sub-

directory.

� Click OK.

2. From the MEC STRUCT menu, click Results.





� Enter [vm_final ] as the name. The DESIGN STUDY dialog

box appears

� Click the bracket_opt\ in the CURRENT DIRECTORY.



FOR RESULT WINDOW “VM_FINAL” dialog box,



NOTES

� For the Title, enter [Von Mises Stress – Optimized

Shape].

� For Quantity, select Stress > Total > Von Mises.

� For Display, select Fringe. Clear Continuous Tone and

Average.

� Select Deformed and accept the Deformed scale 10%.


� Select Auto Start and Reverse.

� Click Accept and Show to finish and display the RESULTS

window.

6. Jot down the following information:

� Maximum von Mises stress ________________;

� Maximum Displacement __________________.

7. Calculate how much the mass has been reduced ___________.




� Enter [final ] for the name.

9. Switch to the standard application. Save and erase the model.



NOTES

MODULE SUMMARY

You have learned:

• How to setup the model appropriately for static analysis, includingdefining the model idealization, constraints, loads and material

properties.

• Define and run the analysis.

• View and interpret the result.

• Optimization the design.


1

Module

Simplifying Models with IdealizationsIn this module, you learn how to use idealizations in

Pro/MECHANICA. Idealizations are the mathematical

approximation of your model's geometry that Pro/MECHANICA

uses to simulate the behavior of your design.

Objectives


• Describe the purpose of using idealizations to simplify yourdesigns.

• Describe the types and applications of idealizations.

• Define rigid connection idealizations.

• Define end- and perimeter-weld idealizations.



NOTES

IDEALIZATIONS

You can use idealizations as simplifications of your designs when running

analyses. During analysis, Pro/MECHANICA calculates stress and other

values in each model idealization. There are different types of

idealizations available in Pro/MECHANICA. It is important to understand

the following idealization types and how they affect the results you will

get for any given analysis.

• Mass- Used to represent a concentrated or point mass without aspecified shape (Structure only).

• Spring- Used to represent a linear elastic (six degrees-of-freedom)spring connection (Structure only).

• Beam- Used to model a structure that is relatively long compared to itsthickness and width, with a constant cross section.

• Shell- Used to model a structure with a constant thickness which isthin compared to its length and width.

• Solid- Used to model a structure that is as thick and wide as it is long.Its cross section and thickness can vary.

When deciding on which idealization to use, consider the structure you are

modeling and how that structure behaves, rather than the geometry. This

will help you select the type of element for your model.

Using Shell Idealizations

You would typically use a shell model when your part is relatively thin

compared to its length and width. Shells are 3-D idealizations that have

length, width, and thickness. Shell models run faster and require less disk

space than solid models – without sacrificing accuracy.


Simpl i f y ing Models wi th Ideal i zat ions Page 2-3

NOTES

To meet Pro/MECHANICA's criteria for shell models, your part must

have a constant or multi-constant thickness. In other words, you can not

shell model a tapered part, but your part can have multiple constant

thickness areas. The thickness of the shell idealization is always

distributed symmetrically about the surface on which it is placed. For this

reason, it is important that this surface actually represent the “mid-plane”

of the model.

Creating the Mid-Surface

By default, Pro/MECHANICA treats all Integrated Mode models as solid

models. You can direct Pro/MECHANICA to treat your part as a shell

model by defining “mid-plane” surfaces. The focus of this chapter is to

teach you how to “compress” a solid model to a shell model.

To model your part as a shell model, you must use the following

procedure:

1. Define Shell Pairs – The first step is to define ‘pairs’ of solid

surfaces which will be ‘compressed’ to form the ‘mid-surface’ of

the model. A surface/shell pair consists of two or more parallel

surfaces on opposite sides of a volume.

2. Test the Pairs Compression – Once the pairs have been defined,

Pro/MECHANICA attempts to compress all the pairs to a

continuous surface model representing the ‘middle’ of the part.

You should review this mid-surface model to ensure that it has

compressed to the desired form, i.e. you should ‘test the

compression’.

3. Verify the Use Pairs Setting – To ensure that Pro/MECHANICA

treats the model as a shell, you should verify that the Use Pairs

setting is selected.

Creating Shells

It is important to note that the procedure described above is used only to

define the mid-surfaces on which shell elements will be placed. In the

Integrated Pro/Mechanica interface these shell elements are not manually

created by the user. Rather, they are automatically created when an

analysis is run. In Integrated Mode, all elements are created by the

Mechanica auto-mesher, known as the AutoGEM utility. The most

important difference between Integrated Mode and Independent Mode is

that elements can be manually created in the Independent Mode.



NOTES

Using Solid Model Idealizations

A solid model is a part that you model using solid elements like

tetrahedral, bricks, or wedges. In Integrated Mode, Pro/MECHANICA

uses only tetrahedrals for solid modeling. You use solid modeling when

your part is as thick and wide as it is long. Your part's thickness, however,

can vary non-uniformly.

There are three different shapes a solid element can take. The three

different solids can be remembered by the number and type of faces that it

takes to define them.

Table 1 Solid element types.

Solid

Type

Description

Brick Two opposite

Quad faces, (total

of 8 points)

Wedge Two opposite Tri

faces, (total of

points)

Tetra One Tri faces and

one opposite point,

(total of points)

Creating Rigid Connections

A rigid connection connects geometric entities, such as surfaces, curves

and points, so that they remain rigidly connected during an analysis. When

you connect entities in this way,



NOTES

• They move together as if part of a single rigid body

• They do not deform, but the rigid body can move as a whole.

Because Pro/MECHANICA uses linear constraint equations to enforce the

rigid rotations, rather than equations with trigonometric functions (such as

sine and cosine), you should use rigid connections only for small rotation

angles of rigidly connected entities. Use rigid connections in this way,

even if you intend to use them in a large deformation analysis.

Pro/MECHANICA supports rigid connections for 3-D models only.

Creating Connections

A connection is the point of contact between two or more parts or

subassemblies. In Pro/MECHANICA, you can use two kinds of

connections—end welds and perimeter welds.

End Welds

Use end welds in assembly models to connect plates. Plates can be curved

and placed at oblique or right angles, such as T or L configurations. Using

the end weld, the shell mesh from one plate is extended to meet the mesh

from the base plate.

You can use end welds to join:

• Two thin wall components at a right angle.

• Two thin wall components at an oblique angle.

• Two offset thin wall components mated at a right angle with a gapbetween the compressed surfaces of the components.

• Two offset thin wall components mated at an oblique angle with nocontact between the components.

Perimeter Welds

Use perimeter welds in assembly models to connect parallel plates, which

may be curved, along the perimeter of another plate. During mesh

generation, a sequence of surfaces is automatically created to connect theselected edges of the top plate to the base plate. Pro/MECHANICA creates

shell elements on the selected surfaces. A series of welds on one or more

of the perimeter edges of the top plate connects it to the base plate. In this

case, the components are touching. The resulting compressed surfaces,

however, are parallel to one another and do not touch. For this type of

geometry, you should use a perimeter weld to connect the two plates.



NOTES


Goal

To use idealizations to simplify a design.

Method

In Exercise 1 you examine mass, spring and beam idealizations. The

model you will be working on is a truss. Since you will be defining the

beam section properties (I-beam, solid circle, etc.) in Pro/MECHANICA,all you need to create for the geometry is the datum curve framework to

set up beam idealizations.

In Exercise 2 you learn how to direct Pro/MECHANICA to treat your part

as a shell model by automatically defining mid-plane surfaces. You create

the two intersecting pipes.

In Exercise 3 you learn how the Integrated Mode automatically meshes

solid models using the T-Bracket.

In Exercise 4 you will learn how to define rigid connections.

In Exercise 5 you will learn how to create end and perimeter welds.



NOTES

EXERCISE 1: Using Mass, Spring, and BeamIdealizations

Figure 1 A truss structure made up of datum curves.

Task 1. Create the truss structure.



5. Click File > New.

6. Select Part from the dialog box. Enter [truss ] for the part name.

7. Leave the Use Default Template check box selected. The new

part will have three defaults, datum planes, and a csys.

8. Turn off the spin center and bell if necessary. Click Utilities >

Environment. Clear both the spin center and ring message bell

check boxes.

9. Change units from Pro/Engineer default to mm N s. Click Setup >

Units. Select mm Ns and click Set. Accept Same Size option.

Click OK > Close.

10. Create a sketched datum curve.



NOTES

� Click [Insert a sketched datum curve] on the right. Select

the default.

� Select the FRONT datum plane, click OK.

� Close the REFERENCES dialog box.

11. Sketch the datum curve as shown in the following figure.

Figure 2 Sketch the datum curves.

Note:

With Intent Manager, constraints are established while you

sketch. In addition, your sketch automatically snaps to the

references you specified. When you finish sketching, Intent

Manager creates a default dimensioning scheme. To override

the default weak dimensions, simply create new dimensions.

12. Click [Done] to finish and then click OK.

Task 2. Create the beams.

1. Enter Pro/MECHANICA Structure. Click Mechanica from the

APPLICATION menu.

2. Click Continue in the UNIT INFO window. Click Structure.



NOTES

3. Accept the default Model from the MEC STRUCT menu. Click

Idealizations > Beams > New. The BEAM DEFINITION dialog

box appears.

4. Enter [hollow_tube ] for the name.

5. Select Edge/Curve from REFERENCE drop-down menu. Click

[Select]. Select all the curves in the model. Click Done Sel.

6. Click More next to the MATERIAL. MATERIALS dialog box

appears. Select Steel. Click the right arrows to assign to the model.

Click OK.

7. From the Y DIRECTION menu, select Vector in WCS and enter

[0,0,1 ] respectively for the X, Y and Z directions.

8. Click More next to SECTION. The BEAM SECTION dialog box

appears. Click New. The BEAM SECTION DEFINITION dialog

box appears.

9. Select Hollow Circle from SECTION TYPE drop-down list.

10. Enter [12.5 ] for R and [8.75 ] for Ri. Click Review > OK.

11. Click OK > OK. Do not define Beam Orientation and Beam

Release. They will be discussed later. Click OK.

12. Click Done/Return.

13. Click View > Default Orientation. Notice that Beam Section icons

appear at intervals along each beam. This gives you a visual idea

of the size and shape of the hollow tubing.

Mass and Spring Idealizations

Task 3. Attach a weight (mass) to the tip of the truss and model a

flexible support (spring) attached at the center of the truss and the ground.

Note:

These Mass and Spring idealizations are placed at datum

points on your model. You will create a datum point inPro/MECHANICA.



NOTES

1. Switch to the front view. Click the Saved Views icon followed by

Front.

2. Create a datum point at the right most vertex of your model. Click

[Create a datum point]. Click On Vertex.

3. Click the vertex on the top right of the truss, corresponds to the

PNT0 shown in the following figure, followed by Done Sel >

Done.

4. Create another datum point, PNT1, using on vertex as shown in the

following figure.

Figure 3 The Truss Model

5. Create a mass at the point that you just created. Click

Idealizations > Masses > New.

6. Accept the default name. Click [Select] and select PNT0

followed by Done Sel. Accept the default type. Enter [100 ] as the

mass followed by OK. The Mass icon appears.

7. Create a spring between PNT1 and the ground. Click Springs >

New.

8. Accept the default name. Select To Ground from the Type drop-

down list. Click [Select] and select PNT1, followed by Done

Sel.

9. Click More next to PROPERTIES. Click New to create a spring

property.

10. In the SPRING PROPERTIES DEFINITION dialog box, enter the

[10, 1000, 10] for Kxx, Kyy and Kzz respectively and accept other

defaults.

11. Click OK > OK > OK. The spring icon appears.



NOTES

Figure 4 The truss model with beam, mass and spring idealizations.

Task 4. Blank the idealization icon display.

1. Click Simulation Display from the VIEW pull-down menu. Then

click Visibilities.

2. Clear Beam Sections, Masses and Springs, followed by OK. The

model now is ready for applying load and defining analyses.

3. Select Done > Return from the IDEALIZATIONS menu.

4. Save and erase the model when finished.

Note:

The model is displayed without the Beam Section icons since

it may interfere with visibility when you are working on a

complex model. Adjust these as necessary for ease of use inPro/MECHANICA.

Tips & Techniques

Items, such as Loads/ Constraints, Simulation features are

displayed together with Pro/ENGINEER features in the Model

Tree. You can use the Model Tree as a “shortcut” to

manipulate these items. Right-click an object in the Model

Tree. A pop-up menu will appear. You can then manipulate

these items.



NOTES

EXERCISE 2: Using Shell Idealizations

Figure 5 Idealize the intersecting pipe as a shell.

Task 1. Create two intersecting pipes.

1. Click File > New.

2. Select Part. Enter [pipes ] for the part name. Use the default

template.

3. Change units from Pro Engineer default to mm N s. Click Setup >

Units. Select mm Ns and click Set. Accept Same Size option.

Click OK > Close.

4. Create a solid protrusion to represent the first pipe.

� Click Insert > Protrusion > Extrude > Done.

� Select the TOP datum plane and click Okay. Select Default

from SKET VIEW.

5. Sketch a circle that is 250 mm in diameter. For a blind depth, enter

[750 ] mm.

6. Change the default attribute to both side protrusion.

� Right-click the protrusion in the MODEL TREE and choose

Redefine.



NOTES

� Double-click the Attribute. Select Both Side > Done > Done.

Accept the depth value, followed by OK. The protrusion should

appear as shown in the following figure.

Figure 6 Finished base protrusion.

7. Repeat the preceding procedures to create a second solid

protrusion with 200m diameter and 750mm depth to represent the

second pipe. Use FRONT as the sketching plane. Use Both Side

option.

8. Insert a round at the intersection of the two cylinders with a radius

of 25 mm.

9. Click Insert > Round.

10. Click Simple > Done.

11. Click Done to accept the defaults Constant and Edge Chain.

Click the two edges that represent the intersection of the two

cylinders, followed by Done Sel. Enter [25] as the radius.

12. Click OK to finish. The model should appear as shown in the

following figure.



NOTES

Figure 7 Unshelled pipe.

13. Shell the pipes with a thickness of 6.25. Click Insert > Shell.

14. Select the four pipe ends as the surfaces to remove, as shown in the

previous figure. Click Done Sel > Done Refs.

15. Enter [6.25 ] as the thickness. Click OK to complete the shell.

16. Save the model.

Task 2. Create the mid-surface of the shell model.

1. Enter Pro/MECHANICA. Click Applications > Mechanica. Read

the unit information and click Continue.

2. Click Structure > Model > Idealizations > Shells.

3. Turn off the Datum Planes, Axes, and Coordinate Systems by

toggling the icons on the toolbar.

4. Shade the model using the icons in the toolbar.

5. Click Midsurfaces > Auto Detect.

Surfaces to remove

Hidden Surfaces to

remove



NOTES

Note:

Pro/MECHANICA highlights one set of surfaces in red and

the opposing surfaces in yellow. The red surface acts as a point

of reference for the pair. Pro/MECHANICA uses this surface

as a view point when determining which opposing surfaces in

the model are part of the pair.

6. From the SHELLS menu, click Compress > Shells only > Show

Compress to test the mid-plane compression. The pairs get

compressed and display in yellow as shown in the following

figure.

7. Click Done/Return > Done/Return > Done/Return.

Figure 8 Compressed pipe.

Create Shells

Now you will examine the shell element mesh in Independent Mode. This

is NOT a require step. Normally, you will set up an analysis and then run

it without ever leaving the Integrated interface. When you run an analysis

in Integrated Mode, the AutoGEM auto mesher will create the elements.

Task 3. Transfer to Independent mode to manually AutoGEM.

1. From the MECHANICA menu, click Settings.

2. Notice that the Use Pairs option is turned on automatically, as a

result of shell idealization. This setting tells Pro/MECHANICA to

place shell elements on the midsurfaces you just defined. If you



NOTES

want to model this part as a solid instead, you would turn off this

setting.

3. Click Indep MEC > Structure to quit Integrated mode, and enter

the Independent mode STRUCTURE.

4. Confirm to exit Pro/ENGINEER. Click OK to close the

information window.

5. Save the model with a new name when prompted. Enter

[pipes_2 ] as a new name. Click Accept.

6. Change the model view to isometric. Click View > Iso > Done.

7. When the model displays, click Settings from the DISPLAY pull

down menu to change the settings.

8. Select the DISPLAY TYPE Smooth Shade, the DISPLAY

QUALITY Fine, and the SHADE Geometry. Select Display

Edges, accept other defaults and click Accept.

9. Notice that only the midsurface geometry was imported into

Independent Pro/MECHANICA.

Task 4. AutoGEM the midsurface.

1. Click Model > Elements > AutoGEM > Surface > All, followed

by <Return>.

2. When you mesh the model, AutoGEM creates shell elements. The

type of idealization determines the types of elements that

AutoGEM will create.

3. Read the SUMMARY window and click OK to finish.

4. Change to an isometric view. Click View > Iso > Done.

5. Adjust the element display settings. Click Display > Settings

from the DISPLAY menu:

� Shade the elements. Select Smooth Shade from the DISPLAY

TYPE drop-down list.

� Select Elements from the SHADE drop-down list.

� Select Shrink All Elements check box with a factor of 0.2 .

� Click Accept



NOTES

6. Visually examine the model. The model should look like the

following figure.

Figure 9 The meshed pipe part.

Task 5. Verify the mid-surface thickness. It is automatically defined

during the shell idealization in the Integrated mode.

1. To verify that the correct part thickness was automatically

assigned, click Edit > Property > Shell Property > Surface.

2. Click the surface mesh lines of any surface. Note that the shell

thickness properties have been assigned.

3. Click Cancel to finish, followed by <Return>.

4. Exit Pro/MECHANICA. Click File > Quit. Answer Yes to

whether or not you want to quit, and No to the saving the model

prompt.



NOTES

EXERCISE 3: Using Solid Idealizations

Figure 10 The finished geometry.

Task 1. Create the base for the t_bracket.

1. Start a new Pro/ENGINEER session. Set the current working

directory as directed by your instructor.

2. Create a part called t_bracket. Click File > New. Enter

[t_bracket ] for the name. Use the default template.

3. Set mm Ns as units. Click Set Up > Units. Select mm Ns. Click

Set > Same Size > OK > Close.

4. Create the base of the T-Bracket using a thin protrusion. Click

Insert > Thin Protrusion > Both Sides > Done.

5. Pick FRONT as the sketching plane and click Okay. Pick TOP as a

horizontal reference, and select the TOP datum plane.

6. Sketch the T-Bracket's base as shown in the following figure.

Since the base is symmetrical about DTM1, use a vertical

centerline on the RIGHT datum plane.



NOTES

Figure 11 Sketch a horizontal line symmetric about RIGHT.

7. Click [Done].

8. Select Both from the THIN OPT menu. Enter [25] for the thin

feature width.

9. Click Blind > Done in the SPEC TO menu. Enter [250 ] as the

extrusion depth.

10. Click OK to complete the feature.

Task 2. Task 2. Create the rib for the t_bracket.

1. The vertical rib can also be created as a thin protrusion. Click

Insert > Thin Protrusion > Extrude > Both Sides > Done.

2. Click Use Prev, followed by Okay.

3. Select RIGHT and the top surface of the first protrusion as

references.

4. Sketch the t-bracket's vertical rib as shown in the following figure.



NOTES

Figure 12 Sketch a vertical line on RIGHT.

5. Click [Done].

6. Click Both from the THIN OPT menu. Enter [25] for the thin

feature width in the message window.

7. Click Blind > Done in the SPEC TO menu. Enter [250 ] as the

extrusion depth.

8. Click View > Default > Preview. The part should appear as shown

in the following figure. Click OK to complete the feature.

Figure 13 The finished T-bracket geometry.

9. Save the model. Click File > Save, followed by <Enter>

Task 3. Task 3. Transfer the part to the Independent mode and

manually AutoGEM it.

Note:

This optional step is performed to illustrate the meshed model.

1. Start Independent session of Pro/MECHANICA. ClickApplications > Mechanica



NOTES

2. Click Continue in the UNIT INFO window. Click Indep MEC >

Structure.

3. Confirm to exit Integrated mode when prompted.

4. Confirm to save the model with a new name when prompted.

5. Enter [t_bracket_2 ] as a new name. Click Accept.

6. To get a better view of your part, click View in the upper right

hand corner, followed by Iso > Done. The model should like the

following figure.

Figure 14 Visualize the T_bracket in the Independent mode.

Task 4. Task 4. Generate the elements.

1. Create the elements by using AutoGEM. Click Model > Elements

> AutoGEM > Volume > All from the DESIGN menu. Click

<RETURN>.

2. A dialog box indicating the number of solid tetrahedral elements

that AutoGEM created will appear. Review the statistics and

record the number of elements and the time below.

� #Elements_________ Time_________ Click OK to finish.

3. To get a better view of the elements, turn off the visibility of all the

entities except the solid elements.

� Click Display > Master Visibilities from the DISPLAY menu.



NOTES

� Click All Off from the bottom of the form.

� Select Solids from the ELEMENTS column and click Accept.

4. Change the element display.

� Click Display > Settings from the DISPLAY menu.

� Select Smooth Shade from the DISPLAY TYPE drop-down

list.

� Select Fine from DISPLAY QUALITY drop-down list.

� Select Elements from the SHADE drop-down list.

� Select Shrink All Elements. Set the shrink factor to 0.2 .

5. Accept the settings. Your mesh should resemble the following

figure.

Figure 15 The bracket part meshed with Tetra solid elements.



NOTES

Task 5. Task 5. Create brick idealizations. Delete the existing Tetra

mesh and all extra points.

Note:

For cases where solution time is critical, it is sometimes

quicker to create idealizations by hand. You hand mesh with

fewer elements than AutoGEM produces, and thus, reduceyour solution time drastically.

1. Re-display all the entities. Click Display > Master Visibilities >

All On > Accept.

2. Delete all the elements you just created. Click Edit > Delete >

Entity.

3. Click Solids > All, followed by <Return>.

4. Click Points > All, followed by <Return>. Click OK when

prompted.

5. Click Main > Geometry > Point > Single Points > Near.

Note:

The Near option places a point on a specified entity near a

projection point.

6. Click the bottom curve of the t_bracket. Then click the point

directly above it, as shown in the following figure.



NOTES

Pick this reference

point after selecting

the curve

Pick this curve first

Figure 16 Create a point for hand mesh.

7. Repeat this process to create three more points - your model should

look like the one shown in the following figure.

Figure 17 Create 3 more points.

8. Manually create elements. Click Main > Model > Elements >

Solid > Brick > Curve.

9. Select the curves shown in the following figure to create the first

face of the solid brick element.



NOTES

Pick these two

curves

First face defined

from curves.

Figure 18 Create the first face of the solid brick element.

10. Select the opposing curves. A solid brick element appears.

11. Create the element in the middle.

� Select Point from the menu.

� Select the 8 points consecutively to form the element in the

middle.

12. Create the rest of the solids using either the Point or Curve option.

When you are completed your model should look like the

following figure.

13. Quit the application when finished. Click File > Quit > Yes > No.



NOTES

Figure 19 The finished hand mesh.

In the hand-created mesh, you have only four elements as compared to

sixty created by AutoGEM. Which one do you think will solve faster?



NOTES

EXERCISE 4: Using Rigid Connections

Figure 20 A symmetric plastic container is cut in half.

Task 1. Retrieve the container assembly and create a rigid connection.

1. Start Pro/ENGINEER. Set your working directory to the folder

that corresponds to the name of the current module.

2. Retrieve the RIGID_CONNECTION.ASM located in the current

working directory. The model is symmetric. All external load

and constraints are also symmetric about the same center plane.

3. Click Application > Mechanica. Click Continue in the UNIT

INFO dialog box.


5. Click Idealizations from the STRC MODEL menu followed by

Rigid Connections > Create.

6. In the Rigid Connection dialog box, accept the default name.

7. Click the Select icon under SURFACE(S) and select the both

halves of the two holes surfaces as shown in the following

figure.



NOTES

Select these

surfaces

Figure 21 Select the indicated surfaces to create the rigid connection.

1. Click Done Sel > OK to finish.

2. Repeat the procedure on the other pair of tabs. The system displays

the rigid connection icons as shown in the following figure.

Figure 22 The rigid connection icon.

3. Click Done/Return to finish.

4. Save and erase the model.



NOTES

EXERCISE 5: Using End and Perimeter Welds

Figure 23 The trailer frame assembly.

Task 1. Retrieve the frame assembly and create an assembly cut.

Because the model is symmetric, the analysis can be performed on one

quarter of the model.

1. Retrieve the FRAME.ASM located in the current working directory.

2. From the ASSEMBLY menu, click Insert > Cut > Extrude > Both

Sides > Done.

3. Specify ASM_TOP as the sketching plane by selecting Sel by

Menu. Pick ASM_TOP from the SELECTION TOOLS dialog box

and hit the Select button. Select Okay.

4. Click Right and select ASM_RIGHT as the reference plane by

selecting Sel by Menu. Pick ASM_RIGHT from the SELECTION

TOOLS dialog box and hit the Select button. Select Okay.

5. Specify the appropriate references and sketch the section, as shown

in the following figure.



NOTES

Sketch these 4

lines

Figure 24 Sketch the cut section.

6. Click [Done] to finish.

7. Click Flip > OK to remove the geometry outside of the rectangular

section.

8. Select Thru All > Done for depth option of both sides.

9. Click AutoAdd > OK so that the cut intersect all the components

based on the depth definition.

10. Click OK to finish cut definition.

Task 2. Compress the mid-surface of the assembly in the ASSEMBLY

mode.


APPLICATION menu. Click Continue in the UNIT INFO window.

2. Click Structure > Model > Idealizations > Shells > Midsurfaces

> Compress > Shell only.

Select as four

references and …



NOTES

3. The system highlights the MID_BAR.PRT and informs you that the

shell model is not defined in this component.

4. Click Yes > ShowCompress. The system displays the shell

models except the MID_BAR.PRT.

Note:

The shell models have been created in all components except

the MID_BAR.PRT. In the ASSEMBLY mode, you can

compress shell models that have been previously created in

PART mode. However you cannot create the shells in the

ASSEMBLY mode.

Task 3. Create the mid-surface of the shell model in part mode.

1. Retrieve the MID_BAR.PRT.


APPLICATION menu. Click Continue in the UNIT INFO window.

Click Structure.

3. Click Model > Idealizations > Shells > Midsurfaces > Auto

Detect > Compress > Shell only > ShowCompress.


Task 4. Compress the mid-surface of the assembly in the ASSEMBLY

mode again. Because all the shell models have been created in all the

components in the part mode, the system compresses and shows all

components.

1. Activated the frame assembly window. Click Window >

FRAME.ASM.

2. Click Structure > Model > Idealizations > Shells > Midsurfaces

> Compress > Shell only > ShowCompress.

3. Reorient to the TOP view and zoom in on the area indicated in the

following figure. Notice that there is a gap between the mid_bar

shell and the cross_bar shell.

4. Click Done > Done/Return.



NOTES

Zoom in to

this area.

Figure 25 The gap between two shell models.

Task 5. Create end welds at one end of a sheetmetal part, as shown in

the following figure. Most end welds have been created for your

convenience.

1. Reorient to the DEFAULT view and zoom in on the area indicated


Create end welds

at this end.

Figure 26 Create end welds at one end of a sheetmetal part.



NOTES

2. From the IDEALIZATIONS menu, click Connections > End

Welds.

3. Specify the end weld surfaces:

� Select the hidden end surface of the sheetmetal MID_BAR.PRT,

as shown in the following figure by using Query Sel.

� Select the other surface, as shown in the following figure.

Select these two

surfaces

Figure 27 Select the end weld surfaces.

4. Create 3 more end welds on the end of the MID_BAR.PRT, using

the same procedures. The system displays the weld icons as shown



Figure 28 Create end welds on all 4 surfaces of the sheetmetal part.



NOTES

Task 6. Task 6. Compress the mid-surface of the assembly in the

ASSEMBLY mode again to verify the end weld connections.

1. From the IDEALIZATIONS menu, click Shells > Midsurfaces >

Compress > Shell only > ShowCompress.

2. Notice that the mid_bar shell and the cross_bar shell are now

connected. However, if you change your view to RIGHT there is a

gap between the bracket part and the cross bar, as shown in the

following figure.

Figure 29 The shell models of the bracket and the cross bar is not connected.

3. Click Done > Done/Return.

Task 7. Task 7. Create a perimeter weld.

1. From the IDEALIZATIONS menu, click Connections > Perim

Welds.

2. Specify the perimeter weld property. Click Current Props >

Thickness. Accept the default.

3. Click New and specify the end weld surfaces:

� Select the hidden end surface of the bracket part as the doubler

surface, as shown in the following figure using Query Sel.

� Select the edges of doubler to define weld location, as shown in

the following figure. Click Done / Sel.

� Select the base surface, as shown in the following figure.

Gap



NOTES

Select the hidden bracket

surface as the doubler

surface

Select these edges.

Select this surface as the

base surface

Figure 30 Create the perimeter welds.


5. Compress the model again to verify the connections. Click Done /

Return > Done / Return.




NOTES

MODULE SUMMARY

In this module you learned:

• How to simplify a design using with idealizations.

• How to simplify a design using shell models.

• How to AUTOGEM elements in Independent mode.

• How to define rigid connections.

• How to define end and perimeter welds.


1

Module

Optimizing Models for AnalysisIn this module, you learn how different geometry creation

techniques used in Pro/Engineer integrate with Pro/MECHANICA.

You also learn Pro/Engineer techniques that reduce calculation time

in Pro/MECHANICA while maintaining accurate results.

Objectives


• Create Pro/ENGINEER models for analysis.

• Use shell elements, solid elements, and regions.

• Model structural assemblies.

• Create 2-Dimensional models.



NOTES

INTEGRATED MODE MODELING

The first step in the Pro/MECHANICA analysis process is part creation.

You need to build a part before Pro/MECHANICA can analyze and

optimize it. The feature creation techniques you use when you build your

part will have a significant positive or negative influence on your modeling

experience. The integrated mode of Pro/MECHANICA unites geometry

creation with analysis. Consequently, you need to take into consideration

downstream activities such as analysis, sensitivity, or optimization as you

build your part. You need to think modeling, not just geometry, and you

need to plan ahead to increase efficiency.

To promote a flexible approach to part modeling, Pro/MECHANICA

enables you to define your model as either a solid or shell. The way you

define your model determines the type of elements Pro/MECHANICA uses

to model your part.

Solid Modeling

A solid model is a part that you model using solid elements like tetrahedrals,

bricks, or wedges. In Integrated Mode, Pro/MECHANICA uses only

tetrahedrals for solid modeling. As a rule, you use solid modeling when your

part is as thick and wide as it is long. Your part’s thickness, however, can

vary non-uniformly.

In Integrated Mode, element creation is automatic and transparent, with

analysis beginning immediately after the mesh is created. Although rare,

there are times when you may want to investigate the mesh.

Modeling Shells

A shell model is a part that you model using shell elements like triangles

and quadrilaterals. Typically, you use shell modeling when your part is

relatively thin compared to its length and width. To meet

Pro/MECHANICA’s criteria for shell models, your part must have either a

constant or a “semi-constant” thickness

Defining Midsurfaces

Pro/MECHANICA does not support shell elements that vary non-uniformly

in thickness (tapered), but your part can have multiple constant uniform

thickness areas.


Opt imiz ing Models fo r Analys is Page 3-3

NOTES

Using shell elements can result in models with fewer elements that will run

faster and require less disk space than a solid model.

For Pro/MECHANICA to treat your part as a shell model, you typically

need to complete a three-step procedure. The purpose of this procedure is to

direct Pro/MECHANICA to treat the part as a shell model and to specify

how shell elements are constructed. The following is a summary of the

procedure:

• Defining shell pairs – The first step is to define ‘pairs’ of solidsurfaces which will be ‘compressed’ to form the ‘mid-surface’ of the

model. A surface/shell ‘pair’ consists of two or more parallel surfaces on

opposite sides of a volume.

• Test the pairs compression – Once the pairs have been defined,MECHANICA attempts to compress all the pairs to a continuous surface

model representing the ‘middle’ of the part. You can and should review

this mid-surface model to ensure that it has compressed to the desired

form, i.e. you should ‘test the compression’.

• Verify the Use Pairs setting – To ensure that Pro/MECHANICA treatsthe model as a shell, you should verify that the Use Pairs setting is

clicked. Pro/MECHANICA uses this setting to determine whether to

perform solid or shell modeling.

Figure 1 A shell model.



NOTES

Automatically Create the Midsurfaces

If you use feature creation methods that implicitly contain a “thickness”

dimension, you can pair these surfaces automatically using the Auto Detect

option. Feature creation methods that implicitly contain thickness type

dimensions are:

• Shells • Ribs

• Ears • Thin Protrusions

• Sheet Metal

Suppressing Cosmetic Features

Pro/ENGINEER allows you to create parts with great detail and precision.

However, there are many features in a model that are irrelevant in analysis

computations. For instance, a part may include a company logo etched on

the surface; although this detail is important for cosmetic purposes and

drawings, it has virtually no effect on stress in the model. Sending features

like this to Pro/MECHANICA serves only to increase solution time and disk

space requirements because AutoGEM has to generate many extra elements

to capture these structurally insignificant features. These features should be

suppressed before you run an analysis.

Preparing Your Part for Static Analysis

To help reduce the number of elements that AutoGEM makes, you can

de-feature a model. Features that you might typically suppress are:

• Small Cuts and Grooves • Rounds and Chamfers

• Locating Holes and Small Counterbores • Ejection Bosses

• Logos

Whether the features in a part are purely cosmetic or structurally significant;

AutoGEM gives them equal importance and will create elements to capture

every small detail. Normally, these types of features can be removed from

the part before the start of a run. This can result in a drastic improvement in

analysis performance, such as faster run times and smaller disk space

requirements without affecting the solution’s accuracy. Usually it is obvious

which features are important to the analysis and which are purely cosmetic.

However, it is up to the user to determine which features are truly

significant to the analysis.



NOTES

Geometric Symmetry

Another way to drastically reduce run time and disk requirements is to take

advantage of symmetry. It is important to note that your model must not

only have symmetrical geometry, but the loads and constraints must be

symmetric about the cutting plane as well. When this is the case, it is a good

idea to prepare your geometry before you begin the analysis process. In

Pro/ENGINEER, you simply cut away the symmetric portions of the model.

Many models can be cut into halves, quarters, or even smaller sections if the

part’s geometry, constraints, properties and loads are all symmetric about a

cutting plane.

Another time saving type of symmetry supported by Pro/MECHANICA is

Cyclic Symmetry. Cyclic symmetry is fairly specialized and is often used

for analysis of rotating machinery such as turbine blades, pump impellers

etc.

Creating Regions

Regions are used to apply loads and constraints to particular “footprints” on

a model. Surface Regions may be created in Pro/MECHANICA to apply

loads and constraints to specific localized surface areas. Surface region

creation is a two step process.

• Defining the region boundary is accomplished either by creating adatum curve to represent the boundary or by sketching the boundary on

the fly. A separate datum curve feature must be created for each region

that you wish to define. You cannot define multiple boundaries with one

datum curve feature.

• Creating the region consists of splitting the model surface into regionsusing the boundary

As of Release 2000i, features such as Datum Points, Curves and Coordinate

Systems can be created either in Pro/MECHANICA or in Pro/ENGINEER.

You must create your regions before defining Mid Surfaces for Shell

Modeling, because assigning regions can invalidate existing shell pairs.

While Surface Regions may be created in Pro/MECHANICA to apply loads

and constraints to specific localized surface areas, similar functionality

allows solids to be split into three-dimensional regions. This is done by

creating Volume regions. Creation of the Volume Region simulation feature

is similar to that of the Cut feature in Pro/ENGINEER. It can be created in



NOTES

part or assembly models and inherits the material properties from the solid

geometry within which they are created. Since results may be viewed by

volume, these regions are beneficial in preparing a model for

postprocessing, making it easier to view internal stresses, strains, etc. Since

elements must be created within a volume region, they can also be used as

an effective means of increasing mesh density when required.

Structural Assemblies

While understanding how parts behave individually is important, many

times these parts are bolted or welded to other parts in an assembly. Their

interaction may require analyzing the parts joined together in a structural

assembly. You must understand how to prepare an assembly for a shell

model and for a solid model, as well as how to take advantage of the

differences between shell and solid models.

Layers and Groups

Layer functionality is fundamental to organization and working efficiently

in Pro/Engineer. When a model is transferred to independent

Pro/MECHANICA you have the option of transferring Pro/E layers to

Pro/MECHANICA groups. The advantages of groups in independent mode

are numerous. Groups allow ease of use when clicking or manipulating

entities—especially elements. This is very useful in both model preparation,

as well as in post-processing. For example, if you want to view the stress

fringe results for only one part in an assembly (as opposed to viewing the

results on the entire assembly), you can view results by group.

Mixed Meshing

In some cases, you combine different element types. This is done simply by

providing Pro/MECHANICA with the geometry associated with the desired

element type and by verifying settings. When MECHANICA, Settings,

Use Pairs is checked on, any existing shell pairs will be meshed with shell

elements, while any remaining unpaired part geometry will be meshed with

solid elements.

This functionality works as well on single parts that are partially paired.

Mixing element types is sometimes critical in balancing time savings with

required accuracy.



NOTES

Interfacing Solids and Shells

How does Pro/MECHANICA handle the intersection of the shell and solid

elements? When the analysis is run in Integrated mode, AutoGEM will

automatically place Links on the edges where shell and solid elements

intersect. Links ensure identical displacements at these locations. If you

were to view a mixed-meshed model in Independent mode, the interface

between the shells and solids would appear as shown in the following figure.

Figure 2 A mixed-meshed model.

The solids are the dark gray, the shell element on the gusset is light gray,

and the links are shown as dotted lines at the intersection of the shells and

solids. They can be created automatically or manually in Independent

modes.

The links are very convenient and are used commonly, but do cause an

increase in run time and can affect accuracy. Therefore, there is an

alternative to links when combining solids and shells, or beams and shells

for that matter. The alternative is to create transition elements between the

shells and solids. This is known as masking. Usually the mask elements are

made of the same material as the solids they interface with. They need to be

very thin so they do not add significant stiffness to the model.



NOTES

Modeling in 2-D

It is possible to define 2-D model types in Pro/MECHANICA Integrated

mode. For Structure, the available model types are Plane Strain, Plane

Stress, and 2-D Axisymmetric. For the Thermal module the available model

types are 2-D Plate, 2-D Unit Depth, and 2-D Axisymmetric. The default

model type is 3D.

The suggested procedure to define a model to be used in a 2-D analysis

using Integrated mode is as follows:

• Define a reference coordinate system - To prepare the model for a 2-D analysis, a reference coordinate system must be created before the

model type is changed. The coordinate system can be created in

Pro/ENGINEER or in Pro/MECHANICA.

• Select the model type - The model type should be selected before anyloads, constraints, or material properties are defined on the model.

Changing the model type from 3-D to 2-D causes all modeling entities to

be deleted. The available model types are:

� 3-D - Use this option if any aspect of the model goes out of the

WCS XY plane. Most of your models will be 3D. This is the

default model type.

� Plane Stress (Structure) or 2-D Plate (Thermal) - Model

should be thin and all modeling entities (properties, constraints,

loads, and geometry) must lie in the XY plane of the reference

coordinate system.

� Plane Strain (Structure) or 2-D Unit Depth (Thermal) -

Model should be sufficiently long such that strains in the

transverse z direction are negligible. All modeling entities must

lie in the XY plane of the reference coordinate system.

� 2-D Axisymmetric - Geometry and all modeling entities should

be symmetric about an axis. All modeling entities must lie in the

positive x portion of the XY plane of the reference coordinate

system.

• Select the geometry and reference coordinate system - Once amodel type is selected, the user is required to select the geometry and

reference coordinate system for the model. If either selection is invalid,

the model type will not be changed.

• Define loads and constraints - Once the model type has beenselected, the loads and constraints can be defined. The model should

only be loaded in the XY plane.



NOTES

• Define shell properties - For a Plane Stress or 2-D Plate model, shellproperties must be defined to assign a thickness to the model. This step

is not necessary for other 2-D model types unless shell elements will be

used. If shell properties are not assigned to the plane stress surface, an

error will be found during error checking.



NOTES


Goal

To learn effective techniques for preparing thick and thin parts for

analysis.

Method

In Exercise 1, you suppress the purely cosmetic features on your part in

preparation for analysis.

In Exercise 2, You create a shell model from a T-bracket and create the

midsurfaces both manually and automatically.

In Exercise 3, you use Auto Detect to shell model the handle part.

In Exercise 4, you create simple sketched and projected regions in order to

understand regions and their affects on pairing.

In Exercise 5, you prepare an assembly for a shell model and for a solid

model.



NOTES

EXERCISE 1: Suppressing Structurally InsignificantFeatures

Figure 3 A realistic handle.

Task 1. Open the part handle.

1. Set your working directory to the folder that corresponds to the name

of the current module.

2. Open the HANDLE.PRT. The model should appear as shown in the

figure above.

Task 2. Create and review the elements in the Independent Mode. Send

the fully featured model to Independent Pro/MECHANICA and use

AutoGEM to find out how many elements are needed to mesh the part. This

will give you an indication of how model complexity can affect the number

of elements, and consequently solution time, and disk space requirements

for a fully detailed part.

1. Click Applications > Mechanica. Click Continue in the UNIT

INFO window



NOTES

2. Before enter the Independent mode, verify that the Use Pairs setting

is turned off. Recall that this is found under Settings.

3. Enter the Independent mode. Click Independ MEC > Structure.

Confirm when prompted.

4. Save the model with a new name when prompted. Enter [handle_2 ]

as a new name. Click Accept.

5. Click View > Iso >Done. The model should appear as shown in the

following figure.

6. Note that all the features were transferred, and that you have a clean

single volume part ready for AutoGEM. To confirm that you have a

single volume, click Review > Model Summary from the tool bar

and verify that there is only one volume. Click OK when finish.

Figure 4 Handle part in the Independent mode.

Task 3. Mesh the part using AutoGEM.

1. Generate the elements, click Model > Elements > AutoGEM >

Volume > All. Then press <RETURN>.

2. Record the number of elements and how long it took from the

AUTOGEM SUMMARY dialog box,.



NOTES

� The number of elements_______________

� Time _______________

� Element type ______________

� Reason for generating this type of element ____________

� Click OK to finish.

3. To get a better view of the elements, turn off the visibility of all the

entities except the solid elements. Click Display > Master

Visibilities from the DISPLAY pull-down menu.

4. Click All Off from the bottom of the form.

5. Select Solids from elements. Click Accept.

6. Shade the elements.

� Click Display > Settings from the DISPLAY pull-down menu.

� Select Smooth Shade for the DISPLAY TYPE.

� Select Fine for the Display Quality.

� Select Elements for the SHADE.

� Select Shrink All Elements check box. Set the Shrink Factor to

0.2 .

7. Accept the settings.

8. Click File > Quit from the top tool bar. Do not save the model.



NOTES

Chamfers

Locator Holes

Name Plate

recess

Figure 5 Suppress these features.

Task 4. Suppress the structurally insignificant features.

1. Start Pro/ENGINEER and set the working directory to the folder that

corresponds to the name of the current module.

2. Retrieve the handle part.

3. Suppress the locator pin holes, the chamfers, and the recess. Click

Feature > Suppress > Clip, select the chamfer from the MODEL

TREE, followed by Done. The system suppresses all the subsequent

features.

Task 5. Transfer to Independent Mode and AutoGEM.

1. Repeat earlier steps to transfer the part to Independent

Pro/MECHANICA and AutoGEM it. Rename it in MECHANICA to

any name you want. Record the number of elements and time to

mesh.

Number of Elements ________ Time to mesh ___________.

2. Compare this mesh to the previous result.



NOTES

3. Click File > Quit. Do not save the model.

Note:

When performing a thermal or modal analysis, the round and the

holes may become insignificant and can be suppressed as well,

further reducing the element count.

Task 6. Reduce the element count by removing symmetric geometry. This

technique is only valid under symmetric situations, which will be discussed

in detail in later chapters.



2. Retrieve the handle part. Notice that the features remain suppressed.

3. Restore all the suppressed features. Click Feature > Resume > All >

Done.

4. Close examination of the part shows that it is symmetric about

DTM3. When the load and constraints are also symmetric about

DTM3, the model can be cut in half.

5. Cut the part in half at DTM3. Click Insert > Cut > Extrude > One

Side > Done.

6. Sketch on the bottom horizontal surface of the handle, with DTM3 as

the TOP horizontal reference plane.

7. Sketch a rectangle to encompass the redundant geometry, as shown


8. Click [Done] to exit the sketching environment.

9. Click Flip if necessary, so that the arrow points to the inside.



NOTES

Figure 6 Sketch the rectangle to cut away the geometry.

10. Select Thru All for the Depth, then click Done> OK. The model

should appear as shown in the following figure.

Figure 7 Half of the handle.



NOTES

Note:

When you AutoGEM this fully featured half model, you would

get about half the number of elements. Using these simple, but

powerful, techniques will drastically reduce analysis time.

Task 7. (Optional) Automesh in the Independent Mode and compare the

element count.

1. Repeat earlier steps to transfer the part to Independent

Pro/MECHANICA and AutoGEM it. Record the number of elements

and the time below.

2. Number of Elements ________ Time to mesh _________.

3. Click File > Quit from the top tool bar. Do not save the model.



NOTES

EXERCISE 2: Shell Modeling by DefiningMidsurfaces

Task 1. Retrieve the T-Bracket. Manually create the first set of pairs.

Define the pairs for the base of the bracket.



2. Retrieve the T_BRACKET.PRT.

3. Enter MECHANICA. Click Applications > Mechanica. Click

Continue > Structure.

4. To prepare the model for shell creation. Click Model >

Idealizations > Shells.

5. Click Midsurfaces > New, accept the default Constant. Select the

two surfaces, shown in the following figure to define the first and

second set of pairs. Use Query Sel as necessary.

Pair #1

Pair #2

Figure 8 Create two surface pairs.



NOTES

Task 2. Test the midsurface compression to verify that you have defined

the pairs correctly.

1. Click Compress from the MIDSURFACES menu, then click Shells

only.

2. To display the midsurface geometry, click ShowCompress. The

pairs get compressed to their midsurfaces and displayed in yellow.

Figure 9 The midsurface.

3. To display the original geometry, click ShowOriginal.

4. Click Show Both to display both the original geometry and the

compressed midsurface simultaneously.

5. Click Done/Return twice when finished. The meshed model can be

visualized in the Independent Mode, as shown in the following

figure.

Figure 10 Midsurface in the Independent Mode.



NOTES

Task 3. Use the Auto Detect option to generate midsurfaces in the T –

Bracket.

1. Delete all existing pairs. Click Model > Idealizations > Shells >

Midsurfaces > Delete > Select All > Yes.

2. To automatically create the pairs, click Auto Detect from the

MIDSURFACES menu.

3. Pro/MECHANICA highlights the pairs that it was able to

automatically create. One surface in each pair is red and the other is

yellow.

4. Test the compression. Click Compress > Shells only >

ShowCompress from the MIDSURFACES menu.

5. The midsurface displays in yellow.

Figure 11 Midsurface compressed from Auto Detect.

6. Display the original geometry as necessary.

7. Click Done > Done/Return> Done/Return.

8. Save and erase the file. Click File > Save. Click Applications >

Standard > File > Erase > Current > Yes.



NOTES

EXERCISE 3: Shell Modeling Using Auto Detect

Task 1. Retrieve the handle part and attempt to Auto Detect and compress

the surface pairs.

1. Open the HANDLE.PRT. Resume all the suppressed features.

2. Click Applications > Mechanica > Structure > Model >

Idealizations > Shells > Midsurfaces.

3. Click Auto Detect > Compress > Shell Only. The system informs

the unpaired geometry.

4. Click Done/Return twice.

Task 2. Suppress the counterbores.

1. Click Applications > Standard. Display the MODEL TREE if

necessary.

2. Suppress the unpaired geometry. Click Feature > Suppress > Clip,

select the HOLE ID 221 from the MODEL TREE, followed by Done.

The system suppresses all the subsequent features. The handle


Figure 12 The handle without unpaired surfaces.



NOTES

3. Enter MECHANICA and Auto Detect the midsurfaces. Note that not

all the surfaces paired. The unpaired geometry are the two separately

created rounds.

4. Manually pair the inner and outer rounds. Click New from the

MIDSURFACES menu. Accept the default Constant, then select the

inner and outer round surfaces.

5. Compress again. The model should appear as shown in the following

figure.

Figure 13 The compressed handle.





NOTES

EXERCISE 4: Creating Regions

In order to constrain or load a specific portion of a part’s surface, you need

to create a region on the surface. You will use the simple 254 x 254 x 25.4

steel plate and create circular regions on each side of the plate where you

want to apply loads.

Figure 14 Create regions for applying the load.

Task 1. Create the first datum curve.

1. Open the REGIONS.PRT.

2. Enter Pro/MECHANICA Structure. Click Application > Mechanica

> Continue > Structure.

3. Create the datum curve on the top of the plate. Click Model >

Features > Datum Curve > Create > Sketch > Done.

4. Select the top surface of the plate as the sketching plane.

5. Flip the arrow so it points out of the plate, followed by Okay.

6. Click Bottom, and pick the bottom side of the plate as the horizontal

reference.

7. Select the top side and the left side for sketching references and

sketch the section as shown in the following figure.



NOTES

Figure 15 The sketched section.

8. Finish the curve and switch to the default view. Click [Done],followed by OK.

Task 2. Create the second datum curve.

1. Create a second datum curve on the bottom of the plate. From the

SIM FEAT OPER menu, click Create > Sketch > Done.

2. Select the bottom surface of the plate as the sketching plane.

3. Specify the appropriate sketching references and sketch the section

as shown in the following figure.



NOTES

Figure 16 Sketch another curve on the other side.

4. Click OK to complete the curve.

Task 3. Use the datum curves you to define the regions.

1. Create a surface region. From the SIMULAT FEATS menu, click Surf

Region > Create > Select > Done.

2. Select the top datum curve.

3. Select the top surface as the surface to split, followed by Done Sel >

Done > OK.

4. Follow the same procedure to create the bottom region.

5. Verify the defined regions. From the VIEW drop-down list, click

Model Setup > Mesh Surface. Select the top and bottom circular

regions. The model should appear as shown in the following figure.

Note:

Mesh surface in the previous step is a Pro/ENGINEER

functionality for visualizing surfaces. It has nothing to do withelement generation.



NOTES

Figure 17 Visualize the surface regions.

6. Close the MESH dialog box and repaint the screen.

Task 4. Manually define the midsurface.

1. Click Done/Return. From the STRC MODEL menu, click

Idealizations > Shells > Midsurfaces > new.

2. Ensure that the model is shaded. Select the top surface of the model

using Query Sel (outside the circular region).

3. Select the bottom surface of the model (outside the circular region).

4. Click Done Sel when finished.

5. Test the compression. Click Compress > Shells only. Notice the

error message in the message box regarding unpaired surfaces, and

also that the COMPRES MDL menu looks different than it usually

does.

Note:

When you created the regions, you actually split the surfaces.

The top and bottom faces now each consist of two surfaces. You

need to include all four surfaces in the pair definition.

6. From the Midsurfaces menu click Edit > Edit Pair. Pick either the

top or bottom surface. Shade the model as necessary.



NOTES

7. Click Add Surface. The unpaired surfaces are not displayed in red

and yellow.

8. Select the top circular region and the bottom circular region. Notice

the color change.

9. Click Done/Return from the EDIT PAIR menu.

10. Test the compression. Click Midsurface > Compress > Shells only

> Show Compress. The entire model should appear as shown in the

following figure.

Figure 18 The compressed shell midsurface.

Task 5. Automatically define the Midsurface. The plate was created as a

thin feature, you can automatically create the pairs.

1. Delete the existing shell. From the MIDSURFACES menu, click

Delete > Select All to delete the surface pairs that you have already

manually defined.

2. Confirm when prompt.

3. From the MIDSURFACES menu, select Auto Detect to automatically

pair the part.

4. Test the compression. Notice how Auto Pair automatically included

the regions you defined.

5. Return to the top-level menu. Switch to Pro/ENGINEER.




NOTES

Note:

You will see how Pro/MECHANICA interprets loads and

constraints that are applied to overlapping regions in later

sections. But for the time being, you just need to know how to

define them.

EXERCISE 5: Creating Volume Regions

Volume regions can be created in part or assembly models. They inherit the

material properties from the solid geometry within which they are created.

Since results may be viewed by volume, these regions are beneficial in

preparing a model for post-processing, making it easier to view internal

stresses. strain, etc.

Task 1. Open the part VOLUME_REGION.PRT.

1. Open VOLUME_REGION.PRT.

2. Enter Pro/MECHANICA Structure. Click Applications >

Mechanica > Continue > Structure.

Task 2. Create a volume region.

1. Click Model > Features > Volume Region > Create > Extrude >

Done.

2. Select either end face of the shaft as a sketching plane.

3. Click OK to accept the direction of feature direction into the

cylinder, followed by Default.

4. In Sketcher, click [Use edge]. Click both semi-circular edges to

form a circular sketch.

5. Click [Done].

6. Click Done to accept the default depth option Blind. Enter [10].

7. Click OK to finish the definition. Switch to hidden line if necessary,

to see the created region.

8. Verify the defined region.

� Click View > Model Setup > Mesh Surface.



NOTES

� Select the surfaces of the created region. The system meshes the

selected surfaces.

� Click Close when finished.




NOTES

Exercise 6: Structural Assemblies

Figure 19 the Gusset Assembly

Task 1. Idealize the GUSSET.PRT as a shell.

1. Open the GUSSET.PRT.



3. Select surface pair to create the midsurface.

� Click Model > Idealizations > Shells > Midsurfaces > New >

Constant.

� Select the paired surfaces. Spin the model as necessary.


5. Switch to the standard application.

6. Save the model.

Task 2. Retrieve the gusset assembly.

1. Retrieve the gusset assembly. This model is created using assembly

constraints, such as MATE and ALIGN. The GUSSET.PRT has been

idealized as shell. The plate is not idealized as shell, hence a solid.



NOTES

2. Verify that the assembly units have been set to mm N s as necessary.

Click SetUp > Units, select mm N s, click Set.

Task 3. Mix idealize the model.



2. Click Model > Idealizations > Shells > Midsurfaces > Compress

> Shells and Solid > Show Compress. The model should appear


Figure 20 An assembly with mixed idealizations.

3. The interface between the shell GUSSET.PRT and the plate parts are

handled by the system. Had you created and run an analysis in the

Independent mode, then the system will create links between the

solid and shell idealization.

4. Switch to Pro/ENGINEER and erase the model.



NOTES

EXERCISE 7: Modeling a 2-D Plane Stress Plate

Task 1. Define the PLATE_2D.PRT as a plane stress model.

1. Open the PLATE_2D.PRT.

2. Switch to the default view. Notice that the back surface of the model

lies in the X-Y plane.



4. Specify the model type. Click Model > Model Type.

5. In the MODEL TYPE dialog box, click Plane Stress. The Select

Geometry and Select Coordinate System option becomes

available.

6. Try to define the Plane Stress model using the front surface.

� Click Select Geometry. Select the front surface of the model,

followed by Done Sel.

� Click the Select Coordinate System. Select the only available

coordinate system, followed by Done Sel.

� Click OK to finish. The system informs that the surface does not

lie in the X-Y plane. Close the information window.

7. Define the Plane Stress model using the back surface.

� Click Select Geometry> Unsel Last. Select the front surface of

the model to remove.

� Select the back surface of the model, followed by Done Sel.

� Click the Select Coordinate System and select the only

available coordinate system.

� Click OK > Confirm to finish. The model is defined as a plane

stress model successfully.

Task 2. Define shell properties to assign material and thickness to the

model.

1. Click Idealization > Shells > New. The SHELL DEFINITION dialog

box appears.



NOTES

2. Define the shell:

� Accept the default name.

� Click [Select]. Select the same surface that is used to define

the plane stress model by using Query Sel, followed by Done

Sel.

� Accept the default type Simple.

� Enter a thickness of [3].

� Assign the material properties to the model. Click More next to

the MATERIAL drop down list. Click AL6061 from the list. Add

it to the model. Click OK to finish material definition.

� Click OK to finish shell definition.

3. Click Done/Return twice to return to the top-level menu.





NOTES

MODULE SUMMARY

You have learned:

• How to simplify a model for analysis by suppressing features and usingsymmetry.

• How to shell models using a midsurface.

• How to create regions for loads and constraints.

• How to prepare an assembly for a shell model and for a solid model.

• How to define a model to be used in a 2-D analysis using Integratedmode.


1

Module

Assigning Material PropertiesIn this module, you learn how to assign material properties to a part

and how to define a library of material properties.

Objectives


• Assign structural and thermal properties to parts.

• Define linear and nonlinear properties.

• Create materials libraries.

• Define temperature-dependent material properties.

• Edit and delete material properties.



NOTES

BASIC MECHANICS OF MATERIALS

You must have a thorough understanding of relevant engineering units

when running analyses Pro/MECHANICA.

• What is the value of density? What are its units?

• What is the value of Young's Modulus? What are its units?

• What is Poisson's Ratio, and what are its units?

• What are the units of Coefficient of Thermal Expansion?

.

Yield Stress

Young’s Modulus is the Slope offthe linear portion of Stress/StrainCurve.

Ultimate Stress

Strain ε

Stress σ

Figure 1: Strain-Stress Curve

Young's Modulus

The previous graph shows a sketch of a general stress-strain curve. These

curves are created by applying an increasing axial load to a test specimen

and by measuring the load and deformation simultaneously. From this

data, the stress (the vertical axis) can be plotted against the strain or

percent elongation (the horizontal axis). As the axial load is increased, the

strain increases in a linear fashion. The slope of this line is called Young's

Modulus. The units are stress (load/area) over strain (change in

length/original length).


Ass igning Mater ia l Propert ies Page 4-3

NOTES

Poisson's Ratio

Poisson's Ratio is the ratio of lateral strain to longitudinal strain. Its value

is between 0.25 and 0.33 for most metals. For example, if you had a round

bar of steel that was 250 mm long and 25 mm diameter, with a Poisson's

Ratio of 0.3, and if you pulled on it so that it deformed 25 mm axially

from 250 mm to 275 mm, the resulting change in diameter would be:

υ = Poisson’s Ratio = axial

lat

εε

where 1.0250

25 ==axialε

so 03.01.03.0 =⋅==υεε lat where d

dlat

∆=ε , d and ∆d are initial diameter

and the change of diameter respectively. then

mmdd lat 75.02503.0 =⋅==∆ ε . The new diameter would be:

mmdddnew 25.2475.025 =−=∆−=

Most materials (when unrestrained) expand when heated and contract

when cooled. The strain due to a 1 degree temperature change is known as

the coefficient of thermal expansion, which is the change in length over

original length over temperature. The units are strain units over

temperature:Fin

in

°,

Cm

m

°

Failure begins whenever the part's actual stress exceeds its Yield Strength.

Pro/MECHANICA always assumes that the Young's modulus has a

constant slope. Analyses that only consider the straight-line portion of the

stress-strain curve (constant Young's Modulus) are considered linear. If

the maximum stress in your model exceeds the material's Yield Stress,

then the reported values are not accurate.



NOTES

.

Yield Stress

Ultimate Stress

Young’s Modulus is the Slope of thelinear portion of Stress/Strain Curve.

Pro Mechanica is a linear Code.

Stress σ

Strain ε

Figure 2 Linear elastic model.

Systems of Units

When changing the units system for a model, you have the option to

convert existing numbers or interpret existing numbers.

If you build a part in IPS (Inch-Pound-Second; Pound in this system

assumes “Pound Weight”) that is 10 inches long, and then switch to

mmNS using the “Convert Existing Numbers” option (same size), then

Pro/ENGINEER would re-dimension your model to be 254mm long.

If you choose the “Interpret Existing Numbers” option (same dimensions),

then your part would become 10mm long.

IPS and I-lbm-S (Inch-Pound Mass-Second) are different unit systems.

The unit for mass in IPS is lbf-sec^2/in, whereas the unit for mass in I-

lbm-S is lbm. These two systems differ as to whether your model is mass

driven or force driven. If your model is force driven, then your units of

mass are considered to be in Weight density which differs from Mass

density by the gravitational constant, gc= 386.4.



NOTES


Goal

To create a library of material properties and assign the properties to a

model.

Method

In Exercise 1, you assign structural and thermal material properties to a

part.

In Exercise 2, you review some basic mechanics of materials.

In Exercise 3, you add your own material to the library.

In Exercise 4, you edit a material properties file and define temperature

dependent material properties.

EXERCISE 1: Assign Structural and ThermalMaterial Properties

Task 1. Define a system of units for your model in Pro/ENGINEER. By

default, Pro/ENGINEER assumes all models are in units of inches-pounds

mass-seconds-Fahrenheit.


name of the current module. Open the T_BRACKET.PRT.

2. Change this setting, click Setup > Units.

3. The dialog box displays the available systems of units. Change to

millimeter Newton Second (mmNs) as necessary.

4. Enter Pro/MECHANICA, click Applications > Mechanica. (Note

the units.)

5. Assign the material properties of steel to this part. Click Structure

> Model > Materials.

6. The material window appears. Add STEEL to the MATERIAL IN

THE MODEL.



NOTES

7. Click Assign> Part, select the part. Click Done Sel.

Task 2. Review the properties.

1. Select STEEL from the Material in model column and click Edit.

2. The MATERIAL DEFINITION dialog box for Steel appears and

gives you the opportunity to review the values for:

• Density • Cost Per Unit Mass

• Young's Modulus • Poisson's Ratio

• Coefficient of

Thermal Expansion

3. Select the Failure Criterion tab in the Material Properties dialog

box. Select the Distortion Energy (vonMises) option from the

drop-down list.

4. Enter [231] for the TENSILE YIELD STRESS.

5. Accept the default N / mm^2 unit from the drop-down list.

6. Click OK when finish.



NOTES

EXERCISE 2: Adding New Materials to the Library

Task 1. Create a new material that is not in the Pro/MECHANICA

Material library. Assign this new material to the T-Bracket. Save this new

material to your own custom material library.

1. Click New, to open the MATERIAL DEFINITION dialog box.

2. Select the units you want and enter the properties listed below.

You could flip from unit to unit by selecting it, MECHANICA will

do the conversion accordingly.

Material Name NICKEL

Description Nickel Material Properties

Mass Density 8802 kg/m3 or 17.08 slug/ft

3

Young's Modulus 206843 N/ mm^2 or 30E06 psi

Poisson's Ratio 0.31

Coeff of Thermal

Expansion

1.296E-05 /C or 7.2E-06 /F

3. Click OK.

4. Add the new material to the library. In the MATERIAL dialog box,

click on the arrow pointing toward MATERIAL IN LIBRARY. Click

Yes to add the property to library.

5. Assign the new material to the part

� Select the new material.

� Click Assign > Part.

� Click the part.

� Click DoneSel > Yes.



NOTES

EXERCISE 3: Edit and Delete Materials

Task 1. Edit all the AL6061 in the Material Library and make Poisson’s

Ratio temperature dependent.

1. Select AL6061 from the Library column and click on the arrow to

place it in the model column.

2. Select it and click Edit.

3. In the Material Properties data form for POISSON'S RATIO type,

click the function button, f(x).

4. In the function definition form, enter the name

[Poisson_Function ], and the description [Temperature

Dependent Poisson’s Ratio ].

5. Select Table from TYPE drop-down list. Select the temperature

drop-down list, and notice that temperature is the only option

available. Material properties can only be dependent upon

temperature.

6. Click Add Row. In the Enter Rows dialog box, click OK to accept

the default values.

7. Enter table values as shown below in the following figure.



NOTES

Figure 3 Enter the table values.

8. Click OK. Note the value of Poisson’s Ratio is now the

Poisson_Function you defined.

9. Click OK to accept.

10. Click on the left arrow to place it back in the library.

11. Click Yes > Yes to overwrite existing library.

12. Close the dialog box. Save the model.

13. Return to Pro/ENGINEER and erase the model.



NOTES

MODULE SUMMARY

You have learned:

• How to assign structural and thermal properties to a part.

• How to create a materials library.

• How to edit material property files.

• How to define temperature dependent material properties.


1

Module

Applying ConstraintsIn this module, you learn how to apply different types of constraints

to your model.

Objectives


• Create different types of constraints.

• Constrain models in Pro/MECHANICA.

• Set the active coordinate system.



NOTES

INTRODUCTION

Constraints and loads are Pro/MECHANICA features that simulate the real-

world environment that you expect your model to encounter.

Pro/MECHANICA uses this information to calculate the behavior of your

model during analyses and sensitivity studies. Your model's optimal shape

and mass will depend on the constraints and loads you define.

A Constraint is an external limit on the movement of a structure or portion

of a structure. A load is a force, pressure, acceleration, velocity or moment

you apply to a structure or portion of a structure. The way you constrain

your model differs depending on whether you are working in Structure or

Thermal.

For Pro/MECHANICA to perform most types of analyses, you must apply

at least one constraint to your model. When you apply constraints in

Integrated Mode, Pro/MECHANICA associates the constraints with the

part's geometry rather than the elements it will create during the analysis

phase.

Before you add constraints to your model, be sure you have all the

necessary geometry and references you need in place. Pay particular

attention to the following items:

• Coordinate Systems – If you plan to make a constraint relative toany coordinate system other than the World Coordinate System

(WCS), then that coordinate system needs to be in place and active.

You can specify constraints relative to a user-defined coordinate

system of the following types:

• Cartesian

� Cylindrical

� Spherical

� Datum Points – If you plan to constrain a specific point on an

exterior curve or surface, your part needs to include a datum

point at that location. As we will discuss later in this class, this

method is generally not recommended because it causes

singularities (infinite stress) to occur in your model. However,

under rare circumstances, you may choose to use this option.

• Regions – If you plan to constrain a specific surface region, yourmodel needs to include the datum curve contours defining that region.

In defining constraints for a Structure model, your goal is to fix portions of

the part's geometry so the part cannot move or can only move in a specific


Apply ing Const ra ints Page 5-3

NOTES

way. Pro/MECHANICA assumes any unconstrained portion of your part

is free to move in all directions available for that model type.

Fixing your part in space provides Pro/MECHANICA with a basis for

understanding how to treat your part. For most Pro/MECHANICA

analyses, the software evaluates the behavior of your part and the stresses

it experiences in terms of the constraints you apply.

Constraints can also be used to reduce model size by allowing you to take

advantage of symmetry.

Edge Constraints

Before you can run an analysis, you need to constrain your model. The

first step in applying constraints to your model is to select the type of

entity you want to constrain. The next step is to fill out the dialog box that

will determine how these entities will, or will not be allowed to move

during the analysis. After the form is filled out, a constraint icon that

graphically represents the allowable movements will be attached to the

entity and, at a glance, you can visually determine how your part is

constrained.

Constraint Icons

The constraint icon is comprised of 2 rows and 3 columns: the top row

represents translational DOFs, and the bottom row represents Rotational

DOFs. The 3 columns are X,Y, and Z (or R, θ, Z for cylindrical coordinate

systems). Each square represents one of the six DOFs. If one of the

squares in the icon is filled, that indicates that a particular DOF as been

fixed or assigned a fixed displacement value. If the square is not filled,

then the entity is free to move in that DOF. Notice how the information

from the data form was transferred to the icon.



NOTES

X Y Z

Translate Row Free Trans X Free Trans Y Fixed Trans Z

Rotate Row Fixed Rot X Fixed Rot Y Free Rot Z

Figure 1 The constraint icon.

• Solid models have only three DOFs that can be constrained (alltranslation). Shell models have six DOFs that can be constrained.

• If you constrain a surface, then you only need to constrain thetranslational degrees of freedom. With edges, you need to constrain thetranslational and rotational degrees of freedom.



NOTES

This constraint restrains the translations of

this surface in the X, Y and Z direction, and

the model is fully constrained.

This constraint restrains the

translation of this edge in

the X, Y and Z direction,

but the model is free to

rotate around the X-axis.

This constraint restrains the

translations of this edge in the

X, Y and Z direction, as well

as the rotation around X, and

the model is fully constrained.

Figure 2 Constraining the model.

Symmetry

Symmetry is a special application of constraints. A part is symmetrical if,

when cut into a section, every point reflected from the mirror plane is the

same. Every load, constraint, all the geometry, and the material properties

must be symmetrical in order to perform a valid symmetrical analysis.

Using symmetry reduces meshing and analysis time, as well as required

disk space.

Cyclic Symmetry

A cyclic symmetry constraint allows you to analyze a section of a

cyclically symmetric model that simulates the behavior of the whole part

or assembly. This relational constraint reduces meshing and analysis time.

The original model (part or assembly) that you take a section of must

exhibit cyclic symmetry. That is, copying the cut section about a common

axis a specified number of times reproduces the whole model. (The



NOTES

number of times must be an integer.) The model must exhibit cyclic

symmetry in all of the following:

• Geometry

• Loads

• Other constraints

• Material type and orientation

In Pro/MECHANICA, a cyclic symmetry constraint prescribes rotation

and displacement on two boundaries to be the same. In Thermal, a cyclic

symmetry constraint prescribes the temperature distribution on two

boundaries to be the same.

Singularities

Constraints and loads should usually be applied to an entity with area. If

you constrain or load an entity with no area, then stress in your model can

theoretically go to infinity. Recall that the basic equation for stress is:

Stress = Load/Area.

For solid models, surfaces, or regions of surfaces constitute area. For shell

models, surfaces, regions, and edges constitute area. Why do edges have

area in a shell model? For shell compressed models, edges are at the

midsurface of the shell that have a defined thickness. Therefore the “area”

of an edge is the length of the edge times its thickness.

For both solid and shell compressed models it is not recommended that

you constrain points; because in both cases the points have no area. The

following table lists entities that should and should not be constrained or

loaded.

Table 1 Constraining various entities.

Shell Solid

Point NO NO

Edge OK NO

Surface OK OK

As the area approaches zero, the smallest of loads will cause

unrealistically high stress in your model. However, this may not be of

concern if your interest is only in deflections.



NOTES

If you apply constraints to datum points or curves, be aware of the

following:

• Point constraints can introduce high stresses and poor stress accuracyin both solid and shell models.

• Curve constraints can introduce high stresses and poor stress accuracyin solid models.

If you cannot avoid a point or curve constraint, and this situation concerns

you, you can work with your model in Linked Mode. Linked Mode

enables you to exclude a small set of elements around the constrained

geometry, thus preventing the stress concentrations from affecting the

analysis.

To avoid stress concentrations in Integrated Mode, you can define a small

region and apply the constraint or load to that region.



NOTES


Goal

To create model constraints.

Method

In Exercise 1, you fix the edge of a plate by applying an edge constraint to

the specified edge.

In Exercise 2, you apply point constraints to remove all six DOFs from themodel.

In Exercise 3, you apply constraints to a surface of the plate.

In Exercise 4, you create a cyclic symmetry constraint.

In Exercise 5, you learn how to correctly apply constraints to shell models.

In Exercise 6, you learn how to create User Defined Coordinate Systems

and to apply constraints with respect to the new coordinate system.

EXERCISE 1: Using Fixed Edge Constraints

Task 1. Fix the edge of a plate from translating in the Z-direction and

rotating with respect to the X and Y axes. All other Degrees Of Freedom

(DOFs) will be free.


name of the current module, and open the PLATE.PRT.

2. Enter Pro/MECHANICA. Click Applications > MECHANICA.

Click Continue in the UNIT INFO window.

3. Apply a constraint. Click Structure > Model > Constraints >

New > Edge/Curve.

4. The constraints dialog box appears. Enter [edge_constraint] for

Constraint name, and leave ConstraintSet1 as a Set name.

5. Click the curve arrow to select the edge. Select the edge of the

plate as shown in the following figure, followed by Done Sel.



NOTES

Figure 3 Select the edge.

6. Keep WCS as the coordinate system.

7. Free Trans. X, Trans. Y, and RotZ. Fix all other Trans. and Rot.

The dialog box should look like the following figure.

Figure 4 The finished constraint dialog-box.

8. Click OK to complete the constraint.



NOTES

EXERCISE 2: Using Point Constraints

Task 1. Delete the edge constraint.

1. Delete the constraint you just created. From the constraint menu

click Delete and select the constraint icon.


Task 2. Create datum points at the locations to constrain.

1. Click Model > Features > Datum Point > Create > On Vertex.

2. Select the three vertices shown in the following figure, followed by

Done Sel > Done > Done Return.

DTM Point 1

DTM Point 2

DTM Point 3

Figure 5 Constrain the vertices of the model.

Task 3. Constrain the first point.

1. Click Constraints > New > Point from the STRC MODEL menu.

2. The CONSTRAINT dialog box appears. Enter [Constraint_1]for the constraint name.



NOTES

3. Leave the default name for the constraint set name,

ConstraintSet1 .

4. Click on the arrow for points. Pick the top left point, PNT0, and

click Done Sel.


6. Fix all the translational DOFs and free all the rotational DOFs, as

shown in the following figure. This constraint removes all

translational DOFs, but the part is still free to rotate around the X,

Y, and Z axes.

Figure 6 Constrain the first point.

7. Click OK to close the dialog-box.

Task 4. Constrain the second point.

1. Click New > Point.

2. Enter [Constraint_2] for the constraint name.


ConstraintSet1 .



NOTES

4. Click on the arrow for points. Pick the bottom left point, PNT1,

and click Done Sel.


6. Fix only the X and Z translations.

7. Leave the Y Translation and all three rotational DOFs free as


Figure 7 Constrain the second point.

8. Click OK.

Task 1. Create a point constraint for the third point.

1. Repeat the above steps to constrain the lower right point.

2. Fix point PNT2 only in the Z translation as shown in the following

figure. (Even though this constraint scheme does not explicitly

remove a rotational DOF, the two bottom points cannot translate in

the Z direction, which removes rotation around the Y-Axis.)



NOTES

Figure 8 Constrain the third point.

Note:

The three translational constraints have removed all six DOFs,

including rotations, even though a rotational box was never

explicitly fixed in any of the CONSTRAINT dialog boxes. It is

not necessary to explicitly fix each DOF in a CONSTRAINT

dialog box in order to remove all six DOFs from a model.

2nd

Constraint removes X and Z

rotations

1st Constraint removes all

translations.

3rd

Constraint

removes Y

rotation

Figure 9 The constrained model.



NOTES

EXERCISE 3: Using Surface Constraints

Task 1. Delete the three point constraints.

1. Click Constraints > Delete and click each Constraint icon.

2. Repaint the screen. Click View > Repaint.

Task 2. Create a surface constraint.

1. Click New > Surface.

2. The CONSTRAINT dialog box appears. Leave Constraint1 as

the default constraint name.


ConstraintSet1 .

4. Click on the arrow for surface. Select the vertical sides of the plate

and then click Done Sel.


6. Fix all the translational DOFs.

7. Leave the rotational DOFs free.

8. Click OK.

9. Click Applications > Standard. Click File > Save and Window

> Close.



NOTES

EXERCISE 4: Constraining Shell Models

Task 1. Apply constraints to shell models using the T-Bracket in order

to hold the two ends of the T-Bracket fixed in all DOF for the model.

1. Open the T_BRACKET.PRT and verify that the units are mmNs.

2. Enter MECHANICA Structure.

3. Click Structure > Model > Idealizations.

1. Define the surface pairs and test the midplane compression. ClickShells > Midsurfaces > AutoDetect > Compress > Shells only

> ShowCompress. The model should appear as in the following

figure.

2. Click Done > Done Return > Done Return.

Figure 10 The compressed bracket.

Note:

The first step to constraining a part is to think about how this

part will actually be held in place. Then, apply the appropriate

constraints to the model. In this example, the part is welded on

the right and left edges of the base into a larger assembly.



NOTES

Task 2. Fully constrain the two vertical surfaces of the t_bracket.

1. Click Constraints > New > Surface.

2. Enter [Constraint_1 ] for the constraint name.


ConstraintSet1 .

4. Click on the arrow for surface. Pick the right and left vertical

surfaces as shown in the following figure. Click Done Sel.

Figure 11 Surface Constraints


6. Fix all DOFs in the dialog box and accept the form.

7. Click OK.





NOTES

EXERCISE 5: Using Coordinate SystemConstraints

Task 1. Create a cylindrical coordinate system aligned with the hole to

define a constraint with respect to.

1. Retrieve the T_BRACKET_HOLE.PRT.

2. Click Applications > MECHANICA > Continue > Structure.

3. Click Model > Features > Coord System > Create > 2 Axes >

Cylindrical > Done.

4. When prompted for the first axis, pick the axis of the first hole.

This reference partially defines the orientation and location of the

coordinate system.

5. When prompted for the second axis, pick the top edge of the plate

as shown in the following figure. With the second reference, the

location of the coordinate system is fully defined.

Figure 12 Select the edge to define the coordinate system.

6. A red arrow pointing downward will appear. Select Z-Axis to

define Z direction.

7. Another arrow is highlighted in red. Select the default Theta=0 to

define the starting point of the Theta direction. The cylindrical

coordinate system is fully defined.

8. Repeat for the other hole to create CS1. Reverse the direction of the

Z-axis arrow as necessary, so that it has the same direction as CS0.



NOTES


Task 2. Simulate bolted bracket by constraining the edges of the holes.

A bolt in a threaded hole allows the hole to displace radially, but not

translate along or rotate around the bolt.

1. Click Constraints > New > Edge/Curve.

2. In the CONSTRAINT dialog box, enter [bolt1] as the name.

3. Click on the [select] under the CURVES. Select the two top

edges that define the top of the right hole and click Done Sel.

4. Click on the [select] under the COORDINATE SYSTEM. Select

corresponding cylindrical coordinate system, followed by Done

Sel.

Note:

Constraints and Loads are always applied with respect to a

current coordinate system. The Mechanica World Coordinate

System (WCS) is the default. In this case, local coordinate

systems are referenced when constraining the model.

5. Free R and fix other Degrees of Freedom.


7. Constrain the second hole on the left hole using the same

procedure and name it [bolt2].

8. Switch to standard application.




NOTES

EXERCISE 6: Using Cyclic Symmetry Constraints

Task 1. Create the cyclic symmetry constraint.

1. Retrieve the WHEEL.PRT.

2. Investigate the last cut by redefining it.

3. Quit redefining without changing anything.

Note:

The wheel part is cyclically symmetric. The last cut is created

to remove geometry, as shown in the following figure. The

geometry you are going to perform analysis on is the one slice

of the entire model.

Figure 13 The cyclic symmetric wheel.

Task 2. Create the cyclic symmetry constraint.


INFO dialog box.


3. Click Model > Constraints > New > Cyclic Symm.

4. Click the [Select] icon right next to the FIRST SIDE. Select the

one pie cut surface as the FIRST SIDE as shown in the following

figure. Click Done Sel to finish.



NOTES

5. Using the same procedure to select the other pie cut surface as the

SECOND SIDE, as shown in the following figure.

Second Side

First Side

Figure 14 Select the indicated surface to create the cyclic constraint.






NOTES

MODULE SUMMARY

You have learned:

• How to define different types of constraints.

• How to create user defined coordinate systems.


1

Module

Simulating Applied LoadsIn this lesson, you learn how to apply the different types of loads

available in Pro/MECHANICA.

Objectives


• Create different load types.

• Describe the difference between point, edge, and surface loads

• Describe when to use each load type.



NOTES

INTRODUCTION

For Pro/MECHANICA to perform most types of analyses, you must load

at least one area of your model. Pro/MECHANICA provides a wide

variety of load types. Below is a list of the types of loads that

Pro/MECHANICA STRUCTURE supports:

• Point • Edge/Curve • Face/Surface

• Bearing • Centrifugal • Gravity

• Pressure • Temperature

Pro/MECHANICA THERMAL supports:

• Heat Loads

You can define as many loads for your model as you like. When you apply

loads in Integrated Mode, Pro/MECHANICA associates the loads with

part geometry, rather than the elements it will create during the analysis

phase.

Before you add loads to your model, be sure you have the geometry and

references you need already in place. Pay particular attention to the

following items:

• Coordinate Systems – If you plan to make a Structure load relativeto any coordinate system other than the World Coordinate System

(WCS), then you must have that coordinate system in place and active.

• Datum Points – If you plan to load a specific point on an exterior

curve or surface, then your part must include a datum point at that

location. Be aware that point loads can introduce high stress

concentrations or theoretically infinite thermal fluxes in your model.

• Regions – If you plan to load a specific surface region, your modelneeds to include the datum curve contours that define the region.


Simulat ing Appl ied Loads Page 6-3

NOTES


Goal

To create different types of loads on a model.

Method

In Exercise 1, you apply Point, Edge, and Surface Loads. You also review

and verify the created loads.

In Exercise 2, you investigate some of the spatial variations that you canassign to loads using linear, quadratic, and cubic interpolation options.

In Exercise 3, you explore how to apply a load using Direction and

Magnitude.

In Exercise 4, you apply a pressure load that varies as a function of a

coordinate system. You also apply a gravity load.

In Exercise 5, you will create a load distribution using the Total Load at

Point Option.



NOTES

EXERCISE1: Applying General Loads

Task 1. Create datum points on the T-Bracket to prepare for loads

creation.



2. Open T_BRACKET_HOLE.PRT.

3. Enter Pro/MECHANICA. Click Applications > MECHANICA >

Continue> Structure.

4. Turn off the display of the constraint symbols.

� Click View > Simulation Display > Visibilities.

� Unselect the constraint sets from the LOAD/CONSTRAINT

SETS list and click OK to finish.

5. Click Model > Features > Datum Point > Create > On Vertex

and add four datum points to the vertices shown in the following

figure.

Figure 1 Points Created For Applying the Load

6. Click Done Sel > Done > Done/Return. Assume for now that you

will model this part as a solid.



NOTES

Task 2. Create a point load.

1. Click Loads > New > Point.

2. A FORCE/MOMENT dialog box appears. Click New to create a

new load set. A LOAD SET dialog box appears.

3. Enter [point_load ] as the load set name and click OK.

4. Enter [point0 ] for the load name.

5. Click [Select] under the POINTS and select PNT0. Click Done

Sel.

6. Keep the default coordinate system WCS.

7. Enter [–10 ] for the Y component. Click OK to finish. Note the Load

icon at point PNT0.

Note:

If it is necessary to apply point or curve loads on a solid

model, and the potential effects of this concern you, you can

work with your model in Independent Mode instead. This

mode enables you to exclude elements around the loaded

geometry, thus preventing infinite stress concentrations from

affecting the analysis.

Point loads can introduce theoretically infinite stresses and

distort your results for both solid and shell models.

Curve loads can introduce theoretically infinite stresses and

distort your results for solid models.

To avoid stress concentrations in Integrated Mode, you can

define regions and apply the load to the region instead of the

point or curve.

Task 3. Review the load you applied to the model.

1. Click Rev Tot Load.

2. When the system prompt for the point, select the datum point

PNT0, where you just applied the load.



NOTES

3. When prompted for a load to review, click the load symbol for the

point load you just created, followed by Done Sel.

4. The LOAD RESULTANT dialog-box appears. It shows the

summary of the resultant load on the point due to the point load.

Review the dialog-box. Notice that the moments are zero, due to

the zero moment arm.

5. Repeat reviewing the resultant load at PNT1, PNT2, and PNT3 due

to the point load PNT0.

6. Notice that FY is -10 for all the points. The values of the moments

change due to the change of the moment arm.

Task 4. Apply an edge load.

1. Click New > Edge/Curve.

2. A FORCE/MOMENT dialog box appears. Click New to create a

new load set. A LOAD SET dialog box appears.

3. Enter [edge_load ] as the load set name and click OK.

4. In the FORCE/MOMENT dialog box, enter [edge_load1 ] for the

load name.

5. Click [Select] under the CURVES and select edge, shown in

the following figure. Click Done Sel.

6. Keep the default coordinate system WCS.



NOTES

Figure 2 Apply load at the indicated edge.

7. Enter [–1] for the X component. The total load of 1 N is uniformly

distributed over the entire edge, producing a unit load of 0.004

N/mm. (The edge length is 250 mm.)

8. Preview the load. Click OK to finish.



NOTES

EXERCISE 2: Applying Spatial Load Variations

Task 1. Edit the edge load to linearly interpolate over the edge length.

1. Click the edge load icon, it should turn red.

2. Right-click the edge load icon and choose Edit. Pro/MECHANICA

highlights the referenced coordinate system and edge. The

FORCE/MOMENT dialog box appears.

3. Change the distribution. Click the second DISTRIBUTION drop-

down list and change from Uniform to Interpolated Over Entity.

4. Click Define, the INTERPOLATION OVER ENTITY dialog-box

appears.

5. Enter [0] for point 1 and [1] for point 2. Click Preview, the load

appears as shown in the following figure.

6. Click OK from the interpolation dialog-box and click OK from the

FORCE/MOMENT dialog box. Note: the load icon still remains

even though you selected Interpolated over Entity.

Figure 3 Interpolate over two points.

Task 2. Review the resultant load at the 4 datum points.

1. Click Model > Loads > Rev Tot Load.



NOTES

2. Select any one of the four datum points when prompted for point.

3. Click the edge load icon from the model, followed by Done Sel.

4. The Load Resultant dialog-box should report FX = -1. Try

reviewing the load at the other datum points. FX should remain a

constant -1, but the moments will vary.

5. Check the load's value at Point 2.

6. Click Done Sel > Done Return > Done Return.

Task 3. Create three additional datum points on the edge to use as

interpolation points.

1. Click [Insert datum point].

2. Click On Curve > Length Ratio.

3. Click the edge you just applied the load to and click Done Sel.

4. Enter [0.25 ] for the curve length ratio.

5. Repeat to add points at [0.5 ] ratio and [0.75 ] ratio along the

curve.

6. Click Done to finish. The bracket should look like in the following

figure.



NOTES

Figure 4 Create three interpolation points.

Task 4. Edit the edge_load to change its interpolation scheme to

quadratic.

1. Click the edge load icon, it should turn red.

2. Right-click the edge load icon and choose Edit. The

FORCE/MOMENT dialog box appears.

3. Define the distribution. Click Define.

4. In the INTERPOLATION OVER ENTITY dialog-box, click ADD.

5. When prompted for an interpolation point, click the datum point in

the center of the curve, PNT5, and click Done Sel > Done/Return.

6. Enter [0], [0], [1] for the interpolation point values.

7. Click Preview and note the parabolic distribution of the load along

the edge shown in the following figure.

Figure 5 Parabolic distribution.

Task 5. To develop a cubic interpolation, add additional datum points to

the edge.

1. Click ADD, in the INTERPOLATION OVER ENTITY dialog-box.

2. Click the datum point at 0.25 ratio (PNT4) to the interpolation.

3. Click ADD to add the datum point at 0.75 ratio (PNT6) to the

interpolation. Read the error message.



NOTES

Note:

When you try to add the 5th interpolation point, you get an

error message. Only 4 points are allowed for interpolated

loads.

4. Click OK to acknowledge the error message.

5. Now set the values for the four remaining points as shown in the

following figure.

Figure 6 fill in the dialog-box.

6. Click Preview and note the cubic distribution as in the following

figure.

Figure 7 Define a cubic interpolation.

7. Click OK from the interpolation dialog-box to complete the review.

Note that the total load is still 1.



NOTES

Note:

For the Interpolated option of Spatial Variation, specifying two

points results in a linear interpolation, three points in a

quadratic interpolation, and four points in a cubicinterpolation.



NOTES

EXERCISE 3: Varying Load Direction andMagnitude

Task 1. Enter the edge_load directions and then input a magnitude in

the Load dialog-box.

1. In the FORCE drop-down list, change from Components to Dir

Vector & Mag.

2. Enter [-1 ] for FX, [1] for FY and [10] for the Mag.

3. Click Preview to review the resulting load distribution, and note

how it is now at a 45°°°° angle to the XZ plane as shown in the

following figure. Click OK to accept the Load.

Figure 8 Preview the Load Distribution

Note:

If Components is used to define the same load, the values of

the components are ( )

071.72

102

=== FyFx

4. Verify the components of the direction and magnitude load you

just applied

� Click Model > Load > Rev Tot Load.

� Select any datum point.



NOTES

� Select the edge load.

� Click Done Sel. The Load Resultant dialog-box should report

Fx = -7.071 and Fy = 7.071 N.




NOTES

EXERCISE 4: Using Pressure and Gravity Loads

Task 1. Apply a pressure load on the right side of the vertical plate. This

load will vary with the square of the distance along the Y-axis.

1. Click [Create a pressure load].

2. A PRESSURE dialog box appears. Click New to create a new load

set.

3. Enter [surface_load ] for the load set name. Click OK.

4. Enter [surface_load1 ] for the load name.

5. Click [Select] and select the surface on the right side of the

bracket and click Done Sel.

Figure 9 The Finished Pressure Load Dialog Box

6. From the DISTRIBUTION drop-down list, select Function of

Coordinates.

7. Define the magnitude. Enter [1] for the P.

8. Click f(x) to define the distribution. The FUNCTIONS dialog box

appears.

9. Click on New. The FUNCTION DEFINITION dialog box appears.



NOTES

10. Enter [y_squared ] for name.

11. Select Symbolic from TYPE drop-down list. Enter [y^2 ] as the

function as shown in the following figure.

Figure 10 Define a load function.

Task 2. Review the function.

1. Click Review, followed by Graph.

2. Enter [12.5 ] as the lower limit (the bottom of the vertical surface)

and enter [250] for the upper limit (the top of the vertical surface).

3. Display the distribution. Click Graph.

4. Zoom in and expand a portion of the graph. Click Utilities > Seg

Graph and select any two points on the graph.

5. Display the full graph. Click Utilities > Full Graph.

6. Display the exact value at a specific point. Click Utilities > Point

Query and select any point. Click OK to confirm.

7. Click File > Exit Graphing when finish.

8. Click Done > OK > OK.

9. Click Preview to view the load distribution. The model should




NOTES


Figure 11 Preview the pressure load.

Task 3. Apply a gravity load to your part.

Note:

In a lot of cases, the gravity load is negligible in magnitude

relative to the applied loads; however, vibration analyses, in

particular, often rely on heightened gravity loads to simulate

drop or shock conditions.

1. Click [Create gravity load].

2. The system reminds you that the gravity load is always applied

using the WCS. Click OK.

3. Create a new load set. In the GRAVITY dialog-box, click New.

4. Enter [gravity ] as the Load Set name. Click OK to finish.

5. Enter [gravity1 ] as load name.

6. Enter [-0.00981 ] for Y.



NOTES

7. Click OK to accept the dialog-box. .Notice the addition of the G

icon at the default coordinate system origin.




NOTES

EXERCISE 5: Creating Load Distributions

Task 1. Retrieve CRANK.PRT and create datum points on the crank to

prepare for load creation.

1. Retrieve the CRANK.PRT.

2. Click Application > Mechanica > Continue > Structure.

3. Click [Insert datum point].

4. Select the At Center from the DATUM POINT menu.

5. Click the edge as shown in the following figure.

Figure 12 Create a datum point at the center of the indicated edge.

6. Click Done Sel > Done to finish.

7. Create another point offset from the point you just created.

� Click [Insert datum point].

� Select the Offset Point from the DATUM POINT menu,followed by Plane Norm.

� Click the surface as the offset plane reference, as shown in the

following figure. Click Done Sel to finish.



NOTES

Figure 13 Select the indicated surface as the offset reference.

� Click the point you just created as the point reference. Click

Done Sel to finish.

� Enter [3] as the offset value.

8. Click Done to finish.

Task 2. Create a surface load with the Total Load at Point

DISTRIBUTION option.

1. Click Model > Loads from the STUC MODEL menu.

2. Click New > Surface.

3. Click the [Select] icon under SURFACE(S) and select the hole

surfaces as shown in the following figure.

Figure 14 Select the load surface.

4. Accept the default world coordinate system WCS.

5. Select Total Load at Point from the DISTRIBUTION drop down

list.



NOTES

6. Select the second point you created as shown in the following

figure.

Figure 15 Select the point for load distribution.

7. Enter [350 ] for the F Z. The dialog box should look like the

following figure.

Figure 16 FORCE/MOMENT dialog box.

8. Preview the load and close the dialog box.




NOTES

MODULE SUMMARY

You have learned:

• How to create different types of loads.

• How to create Interpolated and Function of Coordinates spatiallyvarying loads.

• How to create a load distribution using Total Load at Point option.


1

Module

Running and Evaluating AnalysesIn this module, you define and run an analysis, and evaluate your

results. You learn the differences between Single-Pass Adaptive and

Multi-Pass Adaptive analyses. You also learn how to define run

settings and RAM allocations.

Objectives


• Set up models for analysis.

• Combine structural and thermal analyses.

• Describe the difference between Single-Pass Adaptive and Multi-Pass Adaptive analyses.


Analysis and Resu l ts Page 7-2

NOTES

INTRODUCTION

For this exercise, assume that you are working for a toilet manufacturer

who is developing a new portable toilet unit. You are assigned the task of

developing inexpensive seat for the unit. You want to use readily available

materials capable of surviving a harsh outdoor environment; additionally,

the seat must support a 1570 N (160 kg) load without excessive

deformation or stress.

Analysis Options

An analysis is the calculation of your model's response to its boundary

conditions. Pro/MECHANICA STRUCTURE/THERMAL provides 12 types

of analyses that span a wide range of actual experimental conditions. The

following table lists the analysis types.

Analysis Type Product Use it to find

Static Structure Stress/displacements of the structure

Modal Structure Natural frequencies and mode shapes of the

structure (eigenvalues and eigenvectors)

Pre-stress Static Structure Stress/displacements of the pre-stressed

structure

Pre-stress Modal Structure Natural frequencies and mode shapes of the pre-

stressed structure

Buckling Structure The multiplication factor for the load that will

make the structure buckle, and buckle shape.

Contact Structure Possible contact area and pressure. Stresses and

displacement as a function of loading.

Dynamic Time Response Vibration Response versus time of the structure given any

general time or varying load.

Dynamic Frequency

Response

Vibration Response versus frequency of the structure

given any periodic (frequency varying) load.

Random Vibration Vibration Response versus frequency of the structure

given any Power Spectrum Density input. (PSD)

Shock Response Vibration Response versus time of the structure given any

general shock loading condition.

Steady-State Thermal Thermal Temperature throughout the structure given heat

loads, and convection conditions

Transient Thermal Thermal Temperature throughout the structure given

time-varying heat and/or convection conditions.



NOTES


Goal

To define an analysis, run the analysis, and review the results.

Method

In Exercise 1, you are concerned with the comfort of the seat design.

Therefore, you perform and determine the resulting temperatures, thermal

deformations, and stresses.

In Exercise 2, you define a thermal analysis on the seat. A steady-state

thermal analysis calculates thermal response to specified heat load, subject

to specified prescribed temperatures and/or convection condition. Since all

Pro/MECHANICA modules (Structure, Thermal, and Motion) share a

common database, you do not have to reassign the material properties.

You only need to set up the thermal boundary conditions and define the

thermal analysis.

In Exercise 3, you set up a combined thermal and structural static analysis.

Assuming you already have a defined thermal analysis, this is a four steps

process that requires a special load type called a MEC/T load.

In Exercise 4, you develop three Load Sets: the mechanical load, the

temperature load, and the combined temperature/mechanical load. This

ensures convergence on the combined loading, but also allows you the

flexibility of superimposing and scaling the results from each load set in

the post-processor.

In Exercise 5, you learn about the difference between Single Pass

Adaptive and Multi Pass Adaptive convergence algorithms methods

through the seat example. You create a Multi-Pass static analysis and

compare the resulting answers with those of a Single-Pass.



NOTES

EXERCISE 1: Running a Structural Analysis

Figure 1 A symmetric toilet seat is cut in half.

Task 1. Retrieve the seat model. Create datum curves for region

creation.



2. Open SEAT.PRT.

Tip & Technique:

The model in the preceding figure is symmetric about DTM1

in terms of geometry, properties, constraints, and loads;

therefore using symmetry is recommended. Symmetry takes

advantage of the fact that important model features and

boundary conditions are symmetric about a plane.

3. Insert a datum curve by clicking [Insert a sketched curve].

4. Select the top surface of the seat and click Okay.

5. Select BOTTOM and pick DTM3 datum plane.



NOTES

Figure 2 Sketch the section with two dimensions.

6. Click [Done] to finish, then click OK.

Task 2. Create a datum plane referencing DTM3. This datum plane will

be used in the region creation.

1. Click [Insert a datum plane].

2. Click Through, set the filter to AxisEdgeCurv.

3. Display axis as necessary. Click the A_1.

4. Click Angle, select DTM3, and click Done.

5. Click Enter Value and enter [-55 ].

Task 3. To create the first support's datum curve.

1. Insert a datum curve by clicking [Insert a sketched curve].

2. Select the bottom surface of the seat.

3. Remove the default references and specify DTM4 and A-1 as the

references.

4. Sketch a circle with the center aligned to the DTM4.



NOTES

5. Create the dimension scheme referencing the datum axis, as shown


6. Click [Done] to finish.

Dimension to the

Datum AxisAlign the

sketched circle

to DTM4

Figure 3 Dimension the circle.

7. Repeat the procedures to create a second datum plane and curve 45

degrees from DTM3, the sketch should look like the following

figure.

Figure 4 Create the second datum curve.

8. Save the model.



NOTES

Task 4. Enter MECHANICA and create the regions.

1. Enter MECHANICA. Click Applications > Mechanica >


2. Add the regions to the model, before defining the surface pairs.

3. Click Features > Surf Region > Create > Select > Done.

Tips & Techniques

You can also sketch a Region directly in Pro/MECHANICA

using Features, Surf Region from the STRC MODEL

menu then using Sketch instead of Select option.

4. Select one of the two circles representing the seat's support.

5. Select the bottom surface as the surface to split. Click Done Sel >

Done > OK.

6. Repeat the procedures to define the region on the bottom surface

with the other circle.

7. Repeat the procedures to define the region on the top surface.

8. Click Done/Return to finish.

9. Visualize the surface regions.

� From the VIEW pull-down menu, click Model Setup > Mesh

Surface.

� Click inside the circles. The model should appear as shown in

the following figure. Select Close to complete.

Figure 5 Visualize the regions.



NOTES

Task 5. Compress the midsurfaces


2. Click Model > Idealization > Shells > Midsurfaces > New.

3. Select all five surfaces to be projected onto the compressed

midsurface.

� Select the three new regions

� Then select the two larger remaining surface areas on the top

and bottom of the seat, followed by Done Sel.

4. Click Compress > Shells only > Show Compress. The model


5. Click Done > Done/Return > Done/Return.

Figure 6 The compressed midsurface with regions.

Task 6. Assign the material properties.

1. Click Model > Materials, the MATERIAL dialog box appears.

2. Select PVC from the Materials in Library column and click on the

right arrows to place it in MATERIALS IN MODEL column.

3. Click Assign > Part and click the model, followed by Done Sel.

4. Click on Edit while PVC in highlighted in MATERIALS IN

MODEL column.

5. Click Thermal tab. For the thermal conductivity value, type

[0.667527 ].

6. Click OK > Close.



NOTES

7. Save the model.

Task 7. Apply the support constraint.

1. Apply the support constraints that restrain the seat from moving up

and down. Click Constraints > New > Surface. The

CONSTRAINT dialog-box appears.

2. Click [Select] the two small circular surfaces on the bottom of

the seat representing the supports using Query Sel, followed by

Done Sel.

3. Fix the Y translation only, leaving all other DOFs free, followed

by OK.

Task 8. Apply the hinge constraint.


2. Click [Select]. Select the edge as shown in the following

figure, followed by Done Sel.

Figure 7 Constrain the back edge to simulate the hinge.

3. Free the TransX and RotX and fix all other DOFs, followed by OK.

Task 9. Apply the symmetric constraint to the edge/curve on the cutting

plane.


2. Click [Select]. Select the two top edges on the cutting plane,

followed by Done Sel.

3. Fix X translation, Y and Z rotations. Leave others free.



NOTES

Note:

Since the cutting plane is in the Y-Z direction, the direction

normal the TransX must be fixed. However, an object is free to

move horizontally and/or vertically meaning TransY and

TransZ must be free. Rotation is more difficult to imagine. Of

course, RotX is allowed because you are free to spin an object

as long as its spin axis is normal to the mirror. However, if you

try to spin that object in RotY or RotZ, the object will try to

pass through the symmetry plane, which is not allowed.

Therefore, RotX is free while RotY and RotZ are fixed.

4. Click OK > Done/Return when finished. The model should appear


Figure 8 The fully constrained seat.

Task 10. Load the seat, designing it to support a 160 kg user. Apply a 80

kg which corresponds to 785 N load to the cheek region.

1. Click Loads > New > Surface.

2. The FORCE/MOMENT form appears, for the load name enter

[one_cheek ].

3. Create a new load set. Click New and enter [one_cheek ],

followed by OK. You have created a load one_cheek and a load set

one_cheek.

4. Click [Select]. Select the cheek region, followed by Done Sel.



NOTES

5. Apply a total load of 785 N, uniformly distributed over the region

in the negative Y direction. Enter [-785 ] for Y FORCE component,

followed by OK > Done/Return.

Task 11. Set up a static analysis with the previous created loads and

constraints.

Tips & Techniques:

A static analysis calculates deformations, stresses, and strains

in your model in response to specified constraints and loads. A

static analysis tells you if your model will withstand stress or

break, where the part will break, and how much the part will

move.

1. Click Analyses from the MEC STRUCT menu.

2. The ANALYSIS dialog box appears, select Static and click New.

3. The STATIC ANALYSIS DEFINITION form appears, for the name

Enter [static_seat ].

4. For description, enter [Static analysis of the seat with

a 160 Kg person on it ].

5. Verify that the Constraintset1, one_cheek, are highlighted. Un-

highlight LOADSET1 as necessary.

6. Click on Convergence Tab and select Single-Pass Adaptive.

7. Click on Output Tab and set the Plotting Grids to 7.

8. Click OK > Close to finish.

Task 12. Create a standard design study by running multiple analyses on

a single part.

Tips and Techniques:

You can group analyses together under one standard design

study, and just run the study. If you are running multiple

analyses on a model, this may make file management easier.

The results from all the analyses will be contained within a

single design study result directory.



NOTES

1. Click DesignStudies from the MEC STRUCT menu. The

DESIGN STUDY DEFINITION dialog box displays.

2. For the Study Name, enter [standard_seat ].

3. For the description, enter [Design Study to run a static

analysis of the seat ].

4. For the Analyses, select static_seat.

5. Click Accept followed by Done.

Task 13. Run your study.

1. Click Run from the MEC STRUCT menu.

2. Accept the default Standard_seat(Standard) design study.

3. Click Settings.

4. Change the RAM allocation.

� Click Settings and select Ram Allocation.

� Change it to half the RAM on your machine. (Consult the

instructor as necessary.)

� Click Accept.

Task 14. Start the analysis run and check the Run Status.

1. Click Start.

2. Click Yes when prompted for error checking.

3. Click Summary to monitor the progress of your design study.

4. Click Close > Done when the run is finished.

Task 15. Review the results by creating a fringe plot of stresses.

1. Create a RESULT window. Click Results from the MEC STRUCT

menu.






NOTES


� Enter [vm_static ] as the name, followed by Accept. The

DESIGN STUDY dialog box appears

� Click the Standard_Seat\ in the CURRENT DIRECTORY.



FOR RESULT WINDOW “MAX_PRINCIPAL” dialog box,

� For the Title, enter [Static Analysis Von Mises

Stress on Seat ].

� For Quantity, select Stress > Total > von Mises.

� For LOCATION, select All > Maximum > of shell top/bottom.

� For DISPLAY, select Fringe and clear the Continuous Tone

and Average.

� Accept the Deformed scale 10%.


Note:

More frames will result in smoother animation and take longer

to generate.

� Select Auto Start and Reverse.


5. Use following icons to play and control the result animation:

� [Stop]; [Play]; [Single Step]; [Single Step

Back].

� Stop the animation when finish.

Task 16. Create an animation of the seat displacement. The quickest way

to create a result window that is referencing the same study or analysis as

a result window that has already been defined, is to copy the predefined

results window and then edit its contents.




NOTES

2. Enter [disp_animate ] as the name, followed by Accept.

3. Fill out the dialog-box as shown in the following figure.

Figure 9 Define a displacement result window.

4. Click Accept.

Task 17. Generate a third result window to display the displacements

along the outer edge of the seat.

1. Stop the current animation if necessary. Click [Copy window].

2. Enter [edge_disp ] as the name, followed by Accept.

3. Fill in the dialog-box as shown in the following figure.



NOTES

Figure 10 Define another result window.

4. Click Select to define the LOCATION.

5. Reorient the model in 3D using the <Ctrl> key and the mouse

buttons.

6. Click the outer edge as shown in the following figure.

Select this edge.

Figure 11 Generate the displacement graph of the select the edge.

7. Click the middle mouse button to finish. Click OK when prompted.



NOTES

8. Click Accept.

Task 18. Display multiple windows.

1. Click [Display Result Windows].

2. In the display result window dialog box, click [Select all],

followed by OK. The system starts to animate all animated

windows.

Note:

To control multiple animated windows simultaneously, selectthe windows using <Shift> first.

3. In the selected window, switch the model to the isometric view.

Click View > Spin/Pan/Zoom > Isometric > OK.

Task 19. Edit the legend of the stress result window. Assume the

maximum allowable stress is 35 Mpa. Display higher stress in red.

1. Select the stress result window. Click inside the stress result

window. The system highlights its boarder in yellow.

2. Click Edit > Legend Value.

3. Click the second value from the top in the legend.

4. Enter [35], followed by OK.

5. Click Yes when prompted for linear redistribution.

Task 20. Examine the displacements of the outer edge of the seat.

1. Select EDGE_DISP window.

2. Zoom in on a specific range of the plot.

� Click Utilities > Segment Graph.

� Pick any two points on the graph.

3. Display the entire graph, click Utilities > Full Graph.

4. Change the format of the table.



NOTES

� Click Format > Result Window.

� Clear the Labels and Titles check boxes followed by OK.

Observe the changes in the window.

5. Write the graph data to a file on disk.

� Click File > Export > Graph Report.

� Save in the current directory. Enter [my_data ] for the file

name. Click Accept.

� Click No when prompted for saving the legend information.

Note:

Pro/MECHANICA will write the data to disk in an ASCII filewith a .GRT extension.

6. Click File > Exit Results. Answer No when prompted to save the

window.

7. Click Done/Return to return to the top-level menu.



NOTES

EXERCISE 2: Defining Thermal Analyses

Task 1. Enter Pro/MECHANICA Thermal. Apply a heat load.

1. Click Thermal.

2. Click [Define a heat load on surface]. The HEAT LOAD dialog-

box appears.

3. Enter [thermal_load ] for the name.

4. Create a new load set.

� Click New for load set.

� Enter [therm_load ] as the load set name.

� Click OK.

5. Click [Select]. Select the two circular regions on the bottom of

the seat representing the supports using Query Sel. Click Done

Sel when finished.

6. Enter [-50 ] for Q.

7. Click OK to finish the load definition. Note the addition of the heat

load icons to the display.

Task 2. Apply the fixed temperature of 37° C to the cheek region.

1. Click [Prescribed temperature on surface].

2. Enter [body_temp ] for the name.

3. Create a new constraint set.

� Click New.

� Enter [thermal_const ] for the set name.

� Click OK.

4. Click [Select]. Select the cheek region on the top surface of

the seat. Click Done Sel when finished.

5. Enter [37]. Click OK to finish. Notice the addition of the fixed

temperature “T” icon.



NOTES

Task 3. Apply the convection conditions.

1. Click [Surface convection condition]. The CONVECTION

CONDITION dialog box appears.

2. Enter [side_conv ] for the name.

3. Accept the default therm_const constraint set.

4. Click [Select]. Select the larger region on the bottom of the

seat followed by Done Sel. Do not select the small regions that

already have heat loads applied to them.

5. Enter [0.2 ] for the CONVECTION COEFFICIENT.

6. Enter [25] for the BULK TEMPERATURE to simulate 25 °C air.

7. Click OK to finish. Notice the addition of the convection icon.

Figure 12 Thermal boundary conditions.

Task 4. Define a thermal analysis.

1. Click Analyses. Accept the default Steady State type.

2. Click New. The STEADY THERMAL ANALYSIS dialog box

appears.



NOTES

Figure 13 Define a thermal analysis.

3. Click OK > Close > Done/Return.



NOTES

EXERCISE 3: Running Combined Analyses

Task 1. Create a MEC/T load for a static analysis. The temperature

distribution of the MEC/T load is the result of the previously defined

thermal analysis.

1. Click Structure > Model > Loads > New > Temperature >

MEC/T Temp.

2. Enter [temps1 ] as the name.


� Click New.

� Enter [temps ] as the name.

� Click OK.

4. Uncheck the “Use previous design study” if necessary.

5. Enter [25] for the Reference Temperature.

6. Click OK and note the addition of the MECT icon.

Task 2. Create a load set that contains both thermal and structural load.

First, create the thermal load in the set.

1. The thermal load in the combined load set is identical to the load

created in the previous task. Click New > Temperature > MEC/T

Temp.

2. Enter [temps2 ] as the name.


� Click New.

� Enter [mech_and_therm ] as the name.

� Click OK.

4. Uncheck the “Use previous design study” if necessary.

5. Enter [25] for the Reference Temperature.

6. Click OK and note the addition of the MECT icon.



NOTES

Task 3. Create the structural load in the thermal/structural load set.

1. Click [Create a surface load]. The FORCE/MOMENT dialog-

box appears.

2. Enter [one_side ] as the load name.

3. Assign the load to the MECH_AND_THERM load set created in the

previous task. Select mech_and_therm from the load set drop-

down list as necessary.

4. Click [Select]. Select the cheek region, followed by Done Sel.

5. Enter [-785 ] for Y FORCE component.

6. Click OK. Note the addition of a new load icon in the cheek region.

The model should appear as shown in the following figure.

Note:

It may appear that the loads are doubled on the model. But as

you will soon see, you are not.

Figure 14 Apply a thermal/structural combined load set.

Task 4. Create a static analysis that calculates the thermal stresses as

well as the combined thermal/mechanical stresses.

1. Click Analyses.



NOTES

2. Select Static > New.

3. Fill in the dialog box as shown in the following figure.

4. Click OK > Close.

Figure 15 Define analyses.

Task 5. Run the static analyses.

1. Click Run.

2. Select the analysis, THERMAL_MECH(STANDARD/STATIC).

3. Click Start.

4. Click Yes to when prompted for error detection.

5. Click Summary to monitor the progress of your runs.

6. When the analysis is finished running, scroll up through the

summary file and review the information for all four runs. Review

the Summary file carefully.



NOTES

� How much disk space did it take?

� How long did it take?

� What is the maximum temperature in the seat?

� What is the maximum stress for each case?

� What are the error estimates?

� How many elements did AutoGEM create?

� What are the resultant loads?

7. Click Close > Done when finish.

Note

You have created a single analysis, thermal_mech, and you

selected three Load Sets. Two of these Load Sets need

temperatures from the thermal analysis, thermal_seat, you

defined earlier. Consequently Pro/MECHANICA runs

thermal_seat first and then runs three static analyses, one for

each Load Set. One of these loads, temps, is the stresses due

only to the non-uniform temperature distribution in the seat,

while mech_and_therm is stress due to both the non-uniform

temperature distribution and the 250 lb. person sitting on the

seat. One_side is the stress due to just the person, exactly as onyour first run with the one_cheek load.



NOTES

EXERCISE 4: Combining Loads in Results

Note

When you run an analysis, you may toggle on more than one

load in the Load Sets column. Pro/MECHANICA will analyze

and converge the model on one load set at a time. You can ask

for combined loading in the results section; and the software

superimposes the results from each load case. It is important to

note, if you want to converge on combined loading, you should

have both loads defined under one Load Set name.

Task 1. Examine the temperature distribution due to the heat loads from

the sun and the user.

1. Click Results. Click No when prompted to save current model.

2. Create a window to display the temperature distribution.


� Enter [temperature ] as the name, followed by Accept.

� Click the thermal_mech\ in the CURRENT DIRECTORY.


� In the SELECT ANALYSIS dialog-box, click the

thermal_seat, followed by Accept.

3. Define the result window content

� Select Temperature from the QUANTITY drop down list.

� Select All from the LOCATION drop-down list.

� Select Fringe from the DISPLAY drop down list.

� Clear Animate if necessary.

� Accept other defaults.


Task 2. Define and view the convergence graph of the MPA thermal

analysis.




NOTES

2. Enter [flux_gradient ] as the name, followed by Accept.

3. Define the result window content.

� Select Measure from the QUANTITY drop down list to plot a

measure. Click Select.

� Select energy_norm and click Accept.



4. Hide the convergence graph window.

� Click the FLUX_GRADIENT window.

� Click [Hide result window].

5. Hide the temperature result window using the same procedures.

Task 3. Investigate the stresses due to the thermal expansion.

1. Create a result window to display the thermal stress.


� Enter [therm_stress ] as the name, followed by Accept.



� In the SELECT ANALYSIS dialog-box, click the thermal_

mech, followed by Accept.

2. Select the load set. In the LOAD SET COMBINATION dialog box,

� Clear the Combine Load Sets if necessary.

� Select temps, followed by Accept.


� Enter [Seat Thermal Stresses ] for the name.

� Display Total von Mises Stress.

� Display the Fringe plot.

� Select Deformed > Animate and accept other defaults.


4. Play the animation and pay attention to the maximum stress and

the location of the stress concentration.



NOTES

5. Stop the animation when finished.

Task 4. Create a fringe plot of the combined thermal/mechanical stress.

1. Create a new result window.


� Enter [combined_loads ] as the name, followed by Accept.






� Clear the Combine Load Sets if necessary.

� Select mech_and_therm, followed by Accept.


� Enter [Therm/Mech Stress from Combined Loads ] as

the title.





4. Play the animation and pay attention to the maximum stress and

the location of the stress concentration.

5. Stop the animation when finished.

Task 5. Create a von Mises stress fringe plot for the combined

thermal/mechanical loads, but the loads will be combined in the result

section.



� Enter [combined_results ] as the name, followed by

Accept.




NOTES





� Select the Combine Load Sets if necessary.

� Select one_cheek and temps. Keep the default factors.

Note:

The scale factors can be used to magnify/shrink the effects of

the load sets.

� Clear the mech_and_therm.

� Click Accept.


� Enter [Therm/Mech Stresses from Combined

Results ] as the title.





4. Reorient the view in multiple windows.

� Select multiple windows using the <Shift>.

� Click View > Spin/Pan/Zoom > Isometric > OK.

5. By comparing the combined result and combined load windows,

we conclude that the maximum stresses and stress distributions in

the two plots are almost identical.

6. Exit the result interface. Click File > Exit Results.

7. Save the result window when prompted for saving the result

windows.

� Choose Yes.

� Enter [SPA], followed by Accept.



NOTES

EXERCISE 5: Comparing MPA to SPA

Task 1. Define and run the Multi-Pass analysis.

1. Click Analyses from the MEC STRUCT menu.

2. Make sure Static is selected. Click New.

3. Define the analysis:

� Enter [seat_mpa ] as the name.

� Verify that the Constraint Set ConstraintSet1 is selected.

� Select the Load Set one_cheek.

� Select Multi-Pass Adaptive from METHOD drop-down list.

� Set the Polynomial Order minimum to 1 and the maximum to

9.

� Enter [2] in the PERCENTAGE CONVERGENCE field.

� Select Local Displacement, Local Strain Energy and Global

RMS Stress for the convergence criteria.

� Click Output tab and change the Plotting Grid to 7.

� Click OK > Close.

4. Run the analysis.

� Click Run.

� Select the seat_mpa(Standard/Static) if necessary.

� Click Start to begin the analysis.

5. Monitor the analysis. Click Summary. Notice the following

changes as the analysis run progress.

� Multiple passes are made.

� Each time, the polynomial orders of the equations used in the

solution are increased. Each pass reports fewer “elements not

converged” and more equations than the pass before.

� Eventually, all elements will converge to the specified

percentage and the run will be complete.

Note:

If the analysis does not converge to the specified accuracy,

Pro/MECHANICA will report that, and allow you to look at



NOTES

the non-converged results. In either case, the overall solution

quality of every run is known and can be controlled by

changing the convergence percentage on the analysis form.

Review the Summary file carefully.


Task 2. Define a result window to display a convergence plot and a

fringe plot for the Multi-Pass run.

1. Click Results. Choose No when prompted to save the model.



� Enter [conv_stress ] as the name, followed by Accept.

� Click the seat_mpa\ the CURRENT DIRECTORY.



� Enter [Von Mises Stress vs. P-Pass ] as the title.

� Select Measure from the QUANTITY drop-down list.

� Click Select and select max_stress_vm from the list.

� Click Accept.


4. Click Accept and Show.

Task 3. Create a fringe plot of von Mises stress for the Multi-Pass run.


2. Enter [vm_stress_mpa ] as the name, followed by Accept.


� Enter [Von Mises Stress Multi-Pass ] as the title.

� For Quantity, select Stress > Total Von Mises.

� Display von Mises Stress.




NOTES



4. Retrieve the previously saved single pass adaptive result windows

for comparison. You will lose the two previously created results,

and you may need to recreate the MPA result.

� Click [Open file].

� Select SPA, followed by Accept.

� Click [Display result windows].

� Select the COMBINED_RESULTS window, followed by OK.

5. A close examination of the result windows shows:

� The Multi-Pass Adaptive analysis converges very well.

� The fringe plots of the Single-Pass Adaptive analysis and

Multi-Pass Adaptive analysis are very close.

6. Exit the result interface. Switch to the standard application. Save

and erase the model.

Note:

The answers with the Multi-Pass Adaptive (MPA) and Single-

Pass Adaptive algorithm (SPA) are within 10% of each other.

For larger models SPA can be up to ten times faster and use up

to two-thirds less disk space than MPA. As a default, you

should use SPA as a solution method. MPA is good for cases

where you would like to specify the convergence, and you

want to manually control the convergence percentage.



NOTES

MODULE SUMMARY

You have learned:

• How to define an analysis.

• How to define a combined analysis.

• How to review the results.


1

Module

Analysis and Results: ExamplesIn this module, you will apply Pro/MECHANICA modeling

techniques to real-world examples.

Objectives


• Describe how to build a Pro/MECHANICA model.

• Analyze models for stress and heat distribution.

• Design models around frequency (repetitions per unit time)requirements.


2 Fundamenta l o f Pro /MECHANICA

NOTES

INTRODUCTION

When you begin applying Pro/MECHANICA, you may select large,

complex models to analyze. However, it is recommended that you initially

attempt to apply Pro/MECHANICA to simple, basic models in order to

learn the process of building and analyzing Pro/MECHANICA models.

Analyzing Models

You must apply the following steps when running Pro/MECHANICA

analyses:

1. Create or import geometry

2. Assign material properties

3. Define loads

4. Apply constraints

5. Create elements

6. Define the analysis

7. Run the analysis

8. Review the results

9. Assign design parameters

10. Run a sensitivity study

11. Run an optimization study

12. Update the part geometry

Steps 1 through 8 define an engineering analysis in order to understand

how a model behaves under certain boundary conditions. Steps 9 through

12 enable you to improve a design.


Analysis and Resu l ts: Examples Page 8-3

NOTES


Goal

• Review the basic steps of building a Pro/MECHANICA model.

• Analyze a roller mill bearing.

• Analyze a pan assembly under heat load and gravity.

• Perform a modal analysis and determine the natural frequency of atuning fork for the musical note "G".

Method

In Exercise 1, you will de-feature a model and then set up and run an

analysis. Understanding the Pro/MECHANICA Structure process will

enable you to expand your skills into more advanced techniques such as

optimization.

In Exercise 2, you will analyze the thermal and structural response of a

Pro/ENGINEER assembly.

In Exercise 3, you will design a tuning fork, run a modal analysis, and

then optimize the model.



NOTES

EXERCISE 1: Analyzing Roller Mill BearingMechanical Properties

The model you will be analyzing in this exercise is a mill bearing part.

First, notice that the model contains a large number of features,

specifically, many holes that will increase the size of the

Pro/MECHANICA model. Remember that suppressing features that are

inconsequential to the analysis is recommended practice. Also note that

the model is symmetric and that the boundary conditions are symmetric as

well. Consequently, you will perform two tasks before entering

Pro/MECHANICA:

• Remove features from the part.

• Cut the model in half.

Figure 1: Mill Bearing

Task 1. In Pro/ENGINEER, open the model.

1. Set the working directory to the folder that corresponds to the


2. Open the MILL_BEARING.PRT.

3. Check that units are mm, Newtons and Seconds.



NOTES

Task 2. De-feature the production model to create a simulation model.

The production model is carefully constructed. All the features after Cut

id 2826 can be suppressed.

Note:

There are many pin-holes in your model that will not transmit

any load but will increase the number of elements in the

Pro/MECHANICA model significantly.

Note:

The model is symmetric. It can be cut in half to reduce the

element count. The model is actually constructed in half, and

merged to create the whole model.

1. Display the MODEL TREE if necessary. Click [Toggle model

tree display] to display the MODEL TREE.

2. Click Feature > Suppress > Clip.

3. Click the first Pattern(Hole).

4. Click Done.

Task 3. Enter Pro/MECHANICA Structure and apply material

properties.

1. Enter Pro/MECHANICA. Click Applications > Mechanica >


2. Apply steel material properties to the part.

� Click Model > Materials. The MATERIALS dialog box

appears.

� Select STEEL from MATERIALS IN LIBRARY and add to

MATERIALS IN MODEL.

� Click Assign > Part, then click the part. Click Done Sel >

Close.



NOTES

Task 4. Create two loads that belong to the same load set.

1. Create a bearing load of 1,000,000 Newtons applied to the large

inner cylindrical surface in the positive Y-direction.

� Click [Create a bearing load].

� Click [Select] under the HOLE(S).

� Click the surface as shown in the following figure, then click

Done/Sel.

Figure 2: Bearing Load Surface

� Enter [1000000 ] fort the Y component

� Click Preview. The message displayed is a warning that

Pro/MECHANICA was expecting an entire cylindrical surface

for the bearing load. Click OK since this model has been cut at

the plane of symmetry.

� Click OK > OK.

2. Create a surface load of 500,000 Newtons in the positive Z-

direction applied to the lip of the inner protrusion

� Click [Create a surface load].

� Click [Select] under the SURFACE(S).

� Use Query Sel to select the surface as shown in the following

figure.



NOTES

Figure 3: Surface Load in the Z-direction

� Click Done Sel.

� Enter [500000 ] for the Z-direction.

� Click Preview > OK. The model should appear as shown in the

following figure.

Figure 4: Finished Loads



NOTES

Task 5. Create three constraints that belong to the same constraint set.

1. Create a sliding constraint on the pin hole surfaces.

Note:

A sliding constraint allows a constrained surface to slide in its

own plane but not perpendicular to it. Therefore, the

translation normal to the plane is fixed.

� Click [Create a surface constraint].


� Select the bottom flat surface of all three pin holes, followed by

Done/Sel.

� Fix the Y-direction translation and free the other DOFs. Click

OK when finished.

2. Create another sliding constraint.



� Select the flat surface as shown in the following figure.

Figure 5: Second Sliding Constraint



NOTES

� Fix the Z-direction translation and free the other DOFs. Click

OK when finished.

3. Create a symmetric constraint.



� Select the plane of symmetry.

� Fix the X-direction translation and the Y and Z-direction

rotation. Free the other DOFs. Click OK when finish.

Task 6. Define and run the analysis.

1. Create a static SPA analysis named mill_static . Accept the

other default options when defining the analysis.

2. Run the analysis and monitor the process.

3. Review the summary file. Note the following information.

� Total Elapsed Time ________________

� Total CPU Time _______________

� Solution "efficiency", CPU Time divided by Total Elapsed

Time ______________%.

� Working Directory Disk Usage _________________ Mb.

� Result Directory Size ___________________ Mb.

� Maximum Memory Usage ___________________ Mb.

� How many elements are in the model? __________________

� What is the error of the solution? ______________ %.

� Measure: max_disp_mag __________________

� Measure: max_stress_vm __________________


Task 7. View and interpret the results.

1. Create two result windows:

� Repeated displacement animation (for the display, select

animation instead of fringe).



NOTES

� Repeated von Mises stress animation fringe plot over the entire

model.

2. The result windows should appear as shown in the following

figure.

3. Switch to the appropriate orientations to visually verify the effects

of the boundary conditions.

Figure 6: Displacement and Stress Results

4. In the stress results window, notice the "hot" spots (in red) near the

symmetric boundary.

5. Also notice the few "green" spots near the sliding constraints.

Constraints can often introduce artificially high stresses at the

constraint boundary. These high stresses can typically be

disregarded.

Task 8. Focus on the "hot" spots(von Mises stress higher than 100

MPa).

1. In the stress window, change the fringe legend so that any stress

above 100 MPa (N/mm2) is indicated in red.

� Click Edit > Legend Value.

Note:

If the yield stress of steel is 200 MPa and you want to maintain

a safety factor of 2, no stress in the model should exceed 100

MPa.



NOTES

� Click the first value beneath the Maximum stress.

� Enter [100 ], followed by OK.





NOTES

EXERCISE 2: Analyzing Frying Pan ThermalProperties

In this exercise, you will use Pro/MECHANICA to ensure that a frying

pan distributes heat evenly and is structurally strong.

The model consists of two simple parts—the pan itself and the handle. The

bolts have been removed to simplify the assembly.

Figure 7: Frying Pan

You will perform two types of analysis:

• A thermal analysis will simulate the pan sitting on a hot stove.

• A static analysis will determine if the handle is strong enough towithstand the weight of the pan.

Task 1. Retrieve the pan. Create the datum curves for region creation.

The region is used to represent the ring of heat from a gas stove.

1. Open PAN.PRT. Make sure that unit system is millimeter Newton

Seconds(mmNs).

2. Create circular datum curves on the bottom of the pan.

� Click [Insert a sketched curve].

� Select the bottom surface of the pan.

� Sketch a 177.8 mm diameter circle concentric to the pan.

� Click [Done] to finish.



NOTES

3. Create another circular datum curve with a 127 mm diameter using

the same procedures. The model should appear as shown in the

following figure.

Figure 8: Bottom of The Pan With Two Datum Curves

Note:

The datum curves will be used for regions and must be applied

to the part, not to the assembly. In addition, the curves must becreated as separate features or the region creation will fail.

Task 2. Create two surface regions in Pro/MECHANICA.



2. Split the bottom surface into two surface regions.

� Click Model > Features > Surf Region > Create > Select >

Done.

� Select the outer datum curve, when prompted.

� Select the bottom surface of the pan, when prompted.

� Click Done Sel > Done > OK. The bottom surface is split into

two surfaces.

3. Split the surface again using the other curve.

� Click Create > Select > Done.

� Select the inner curve.

� Select the bottom, inner surface of the pan.



NOTES

� Click Done Sel > Done > OK. The bottom, inner surface is

split into two surfaces (for a total of 3 surfaces on the bottom

of the pan).


5. Switch to the standard application. Save and close the window.

Task 3. Retrieve the handle. Create the datum curves for region

creation. The region will represent the area held by hand.

1. Open PAN_HANDLE.PRT. Make sure that unit system is

millimeter Newton Seconds(mmNs).

2. Create a datum plane offset from the end of the handle 116 mm

towards the pan.

� Click [Create a datum plane].

� Select Offset. Select the end surface of the handle.

� Select Enter Value. Enter [-116 ], followed by Done.

3. Create datum curves.

� Click [Create datum curve].

� Select Intr.Surfs > Done > Whole.

� Select the top surface of handle.

� Select Single and select DTM4 that was just created.

4. The model should appear as shown in the following figure.

Figure 9: Datum Curve Created On The Handle



NOTES

Task 4. Enter Pro/MECHANICA and create a region on each of the four

sides of the handle.



2. Split the top handle surface into two surface regions.

� Click Model > Features > Surf Region > Create > Select >

Done.

� Select the datum curve, when prompted.

� Select the top, bottom, and side surfaces of the handle, when

prompted.

� Click Done Sel > Done > OK. The four surfaces are each split

into two surfaces, for a total of eight surfaces.

3. Verify that four regions have been created. Click Show All. Do

not worry about which surfaces highlight. What is important is

that there are now separate surfaces on which loads or constraints

may be applied.


5. Switch to the standard application. Save and close the window.

Task 5. Open the frying pan assembly model. Create a datum curve on

the pan where it intersects with the handle. The datum curve will be used

for surface region creation.

1. Open the FRYING_PAN.ASM. Make sure that unit system is

millimeter Newton Seconds (mmNs).

2. Click [Select primary item].

3. Right-click the pan from the Model Tree and choose Insert

Feature.

4. Click [Create datum curve].

5. Select Composite > Done > Exact > Done.

6. Click the four edges of the handle part that are in contact with the

pan.

7. Click Done > OK to finish.



NOTES

Task 6. Create a surface region where the handle intersects the pan.


Continue > Thermal.

2. Click Model > Features > Surf Region > Create.

3. Select the pan, when prompted for component.

4. Choose Select > Done.

5. Select the rectangular datum curve, when prompted for curves.

6. Select the outer surface of the pan that intersects the handle, when

prompted.

7. Click Done Sel > Done > OK > Done/Return.


1. Apply material properties. Click Model > Materials.

� Assign the pan AL6061

� Assign the handle STEEL.

Note:

Aluminum has more than 4 times the thermal conductivity of

steel, making a good material for cooking. On the other hand,

steel has lower thermal conductivity, making it a good

candidate for the handle because of the high thermal

resistance.

Task 8. Simulate the cooking heat with the appropriate boundary

conditions.

1. Simulate the cooking heat from the gas stove (12,500 BTU/hr)

with a heat load.

� Click Model > Heat Loads > New > Surface.

� Enter [cooking_heat ] as the name.

� Click [Select] and select the ring shape surface region.

Click Done Sel.

� Select Total Load from the DISTRIBUTION drop-down list.



NOTES

� Enter [3661000 ].

Note:

The value is calculated by converting 12,500 BTU/hr into N

mm/sec.

N mm/sec is the unit for heat flux in the mmNsec unit system.

� Click OK > Done/Return to finish.

2. Simulate the heat loss due to ambience air with a convection

boundary condition.

� Click Model > Bndry Conds > New > Conv Cond > Surface.

� Enter [cool_air ] as the name.

� Click [Select] and select the following surfaces:

• The narrow top surface.

• Internal and external surfaces of the round.

• Internal and external surfaces of side.

Note:

When selecting the external side surfaces. The rectangular

region where the pan intersects the handle is excluded.

� Click Done Sel.

� Enter [0.4 ] for CONVECTION COEFFICIENT.

� Enter [25] for BULK TEMPERATURE.


3. Simulate the heat loss due on the cooking surface with a

convection boundary condition.

� Click New > Conv Cond > Surface.

� Enter [cooked_food ] as the name.

� Click [Select] and select the interior bottom surface where

the food is cooked.

� Click Done Sel.


� Enter [100 ] for BULK TEMPERATURE.



NOTES


4. Simulate the heat loss through the handle surfaces not held by the

cook's hand with a convection boundary condition.

� Click New > Conv Cond > Surface.

� Enter [handle_heat_loss ] as the name.

� Click [Select] and select the handle surfaces that are not

touched by hand.

� Click Done Sel.


� Enter [25] for BULK TEMPERATURE.

� Click OK > Done/Return to finish.

Task 9. Create a steady-state thermal analysis.

1. Click Analyses. Accept the default Steady Thermal analysis type.

2. Click New. Enter [pan_therm ] as the name.

3. Make sure you select the correct constraint and load sets and

accept all other default options.

4. Click OK > Close > Done/Return when finish.

Task 10. Simulate the structural aspect of the pan model. The materials

have already been defined in the previous tasks. Define the constraint

(where the cook is holding the handle) and the load (gravity).

1. Enter Pro/MECHANICA Structure. Click Structure.

2. Define a surface constraint that simulates the holding hand.



� Select the four surface regions held by hand.

� Fix X, Y and Z-direction translations and free the other DOFs.

� Click OK when finish.

3. Define a gravity load.

� Click [Insert a gravity load].



NOTES

� Enter [-9810 ] for Z.

� Preview and click OK to finish.

Task 11. Create a static structural analysis.

1. Click Analyses. Accept the default Static analysis type.

2. Click New. Enter [pan_static ] as the name.

3. Make sure you select the correct constraint and load sets and

accept all other default options.

4. Click OK > Close when finish.

Task 12. Create a design study that includes the structural and thermal

analyses.

1. Click DesignStudies.

2. Enter [pan_study ] as the name.

3. Select both the pan_therm and the pan_static .


Task 13. Run the analysis and monitor the process using the summary

file. Note the following information when the analysis is finished.

1. Total Elapsed Time ________________

2. Total CPU Time _______________

3. Working Directory Disk Usage ___________________ Mb

4. Result Directory Size ___________________ Mb

5. Maximum Memory Usage ___________________ Mb

6. How many elements are in the model? __________________

7. What is the error of the solution? ______________ %

8. What is the maximum displacement magnitude? __________mm

9. What is the maximum Von Mises stress? ____________ N/mm2



NOTES

10. What is the maximum temperature? ____________ oC

Task 14. Create result windows to display the results.

1. Create an animated result window to view the displacement. Use

"animation" as the display instead of fringe.

2. Create an animated fringe plot to display von Mises stress.

� As expected, high stresses occur at the junction between the

handle and the mounting plate. However, since these stress

values are much lower than the material's yield strength, these

stresses are not a big concern.

3. Create a result window to display temperature distribution.

� Notice that the temperature is evenly distributed around the

thick aluminum bottom.

4. Exit the Results window. Save and erase the model.



NOTES

EXERCISE 3: Analyzing a Tuning Fork

Tuning forks produce a sound by vibrating at specific resonant

frequencies. If the resonant frequency is within the audible range of 20 Hz

to 20,000 Hz, then the frequency can be classified as a musical note. For

example, the note, middle-C, a vibrates at 256 Hz, whereas the note, E,

vibrates at a frequency of 320 Hz. Piano tuners and guitar players use

tuning forks to tune their instruments to certain musical notes.

In this exercise, you tune a fork to the musical note "G", which vibrates at

384 Hz.

Task 1. Build the simulation model.

1. Open the part FORK.PRT. Make sure the units are in mm,

Newtons, and seconds.

2. Enter Pro/MECHANICA Structure and apply steel material

properties to the tuning fork part.

3. Fully constrain the handle surface of the fork (the cylindrical

protrusion).

Task 2. Run the modal analysis.

1. Click Analyses > Modal (from the drop down list) > New.

2. Enter [fork_mode ] for the analysis name. Change the number of

modes to [1], because we are interested in the lowest, or primary

mode.

3. Accept all other defaults.

4. Run the analysis.

Task 3. Verify the accuracy of the model and note the following:

1. Total Elapsed Time ________________

2. Total CPU Time _______________

3. Working Directory Disk Usage ________________ Mb



NOTES

4. Result Directory Size ___________________ Mb

5. Maximum Memory Usage ___________________ Mb

6. How many elements are in the model? __________________

7. What is the error of your solution? ______________ %

Task 4. Now that you understand the resources the analysis required and

the error it produced, you are ready to start reviewing the results. In the

summary file, you may find the calculated modal frequency.

1. What is the modal frequency? _________________ Hz. You have

determined that this frequency is approximately G# (G-sharp)

which is close, but half a note from your desired frequency of G.

2. Create a displacement animation result window.

Task 5. Define a design parameter. The length of the tuning fork will

dictate its resonant frequency. .

1. Assign a design parameter to the length of the fork. Click Model >

Dsgn Controls > Design Params.

2. Click Create > Dimension > Select. Pick the fork feature. Pick

the 91.24mm dimension as shown in the following figure. Enter

[Fork_length ] as the new name for design parameter.



NOTES

Figure 10: Design Parameter On The Tuning Fork Length

3. Define the range from a minimum of 90 to a maximum of 110.

4. Click Accept > Done.

Task 6. Optimize the model. To achieve the desired note of G, the

resonant frequency must be 384 Hz. This will be accomplished by varying

the length of the fork.

1. In Pro/MECHANICA Structure, define an optimization. Click

DesignStudies.

2. For the optimization name, enter [fork_opt ].

3. Select Optimization from the TYPE drop-down list.

4. Clear the Goal check box.

5. Define the Limits on Measures.

� Click Create

� Select modal frequency from the pre-defined measure list

� Click Accept.

� Set modal_frequency equal to [384 ].

6. Select the Fork_length parameter in the parameters section.

7. Accept all other defaults.

8. Run the optimization.

Task 7. Verify the results of the optimization.

1. Enter the total Elapsed time. ____________________ sec

2. What is the final value of design parameter? ____________ mm

3. What is the optimized modal frequency? _______________ Hz

4. Is this within the 1% specified in the optimization convergence?

________________



NOTES

Task 8. Update the model using the optimized design parameter.

1. Click Model > Dsgn Controls > Optimize Hist > Enter Study.

Enter [fork_opt ] when prompted and answer Y to all questions.

2. When you have completed this process, the fork will be tuned to G.

3. Create a plot of the modal frequency vs. optimization pass. It

should look like the following figure.

Figure 11: Modal Frequency vs. Optimization Pass





NOTES

MODULE SUMMARY

You have learned how to:

• Set up and run a Pro/MECHANICA structural analysis.

• Set up and run a thermal analysis and a structural analysis,simultaneously.

• Set up and run a modal analysis and an optimization design study.


1

Module

Running Sensitivity and Optimization StudiesSo far, you have learned how to model and analyze a part in

Pro/MECHANICA. In this lesson, you will learn the tools that

enable you to determine how sensitive measures such as stress,

displacement, and mass are to changes in model parameters. You

will also learn how to optimize your model by setting goals and limits

on measures, while varying model parameters.

Objectives


• Set up and run design and optimization studies.

• Describe the purpose of design parameters.



NOTES

INTRODUCTION

Sensitivity studies enable you to more fully understand the effects of

varying the design parameters on your model. You can use these studies to

determine how sensitive a particular quantity, such as von Mises stress, is

to variations of a particular dimension parameter. Pro/MECHANICA

provides the following sensitivity capabilities:

Running Global Sensitivity Studies

Global sensitivity studies are used to generate a picture of how measures

respond to changing a design parameter over a specified range (usually a

large range, hence the name global). Global sensitivity studies provide the

big picture and will be most useful in understanding the overall effect of a

given parameter.

Running a global sensitivity study helps you understand in detail how

changes are affecting your part. You will then use this information to set

up the optimization study.

Normally you would run global sensitivity studies on all the parameters

that survived the local sensitivity study, but in the interest of time, you

will run global sensitivity studies for limited parameters.

In the exercise, you will run a global sensitivity on the slot length

parameter to get a better understanding of its impact on your model.

However, by doing so, you can only determine the optimal value for a

given parameter if it were varied alone. But would this optimal parameter

value be the same if other design parameters were changed

simultaneously? The answer is most likely no. This is why you need the

optimizer. However, this does give you a good starting position for the

optimizer.

Running Local Sensitivity Studies

Local Sensitivity Studies are used to calculate the sensitivity of your

model's measures to perturbations (very slight changes) in parameters.

Pro/MECHANICA uses local sensitivity to perturb a dimension parameter

by 1% to estimate the derivative of your measure with respect to the

parameter. Thus, for a given location in parameter space, you may take a

"snapshot" of the sensitivity of your model subject to all parameters. If


Running Sens i t i v i ty and Opt imizat ion Studies Page 9-3

NOTES

parameter A induces a slope of your measure of 100, while parameter B

induces a slope of your measure of 0.01, then you may postulate that

changing the parameter A will have a bigger effect than working with

parameter B. Therefore, you use local sensitivity to narrow your selection

of dimension parameters to the most important ones.

Running Optimizations

An optimization study adjusts one or more parameters to best achieve a

specified goal or to test feasibility of a design, while respecting specified

limits.

To create an optimization study, you define the following components:

Goal – You select a measure to minimize or maximize as the study's goal.

Limits – You define limits on one or more measures that

Pro/MECHANICA cannot violate during the optimization.

Parameters – You select one or more design parameters you want

Pro/MECHANICA to adjust to achieve the goal. You will also define a

range and initial value for each parameter.

The goal and limits are each optional, but you must have at least one goal

or one limit.

Pro/MECHANICA adjusts the model's parameters in a series of iterations

through which it tries to move closer to the goal while satisfying any

limits. If you have no goal, Pro/MECHANICA simply tries to satisfy your

limits. An optimization with no goal is sometimes called a feasibility

study. If you do not define a goal, you must define limits. Without a goal,

Pro/MECHANICA searches for the first feasible design that satisfies the

limits you define.

When defining a goal and limits, you can select measures associated with

different analysis types. You can set up an optimization that would

perform any of Pro/MECHANICA's analysis types except motion and

contact. For example, you could optimize the clip for stress, displacement,

natural frequencies (modes), and temperature simultaneously.



NOTES


Goal

To use sensitivity and optimization design studies to view the effects of

design variables and find an optimized model.

Method

In the first exercise you will create a Pro/MECHANICA model and define

design parameters.

In the second exercise, you will run a sensitivity study to view the effects

of varying the design parameters on specific aspects of your model.

In the third exercise, you will run an optimization study to find an

optimized set of dimensions for your model. The goal is to reduce the

stress in this model while increasing the maximum deflection to a value

greater than 7 mm, but less than 9 mm. You will also attempt to reduce the

weight of the current design.



NOTES

EXERCISE 1: Optimizing a Belt Clip

The belt clip model you will be optimizing, as shown in the following

figure, fits onto a portable electronic device. The part is inserted and

released from its latch by applying a 2.5 N force downward on the tab.

The catch that protrudes down from the curved tip moves up and must

clear a latch that is 7 mm high, but the maximum deflection cannot exceed

9 mm. In addition, the stresses must be kept to a minimum without

increasing the weight of the part.

Catch

7 mm <displacement < 9 mm

Press down the

tab with 2.5 N

Constrain the

Flange

Clip Body

Curved Tip

Figure 1 The Clip Part

Task 1. Build the simulation model by cutting away half of the

symmetric model.



2. Open the part CLIP.PRT. Check that units are mm, Newtons and

Seconds.

3. Cut away half of the part. Click Insert > Cut > Extrude. Click

Both Sides > Done.



NOTES

4. Select DTM2 as the Sketching Plane and click Default as

orientation reference. Create a sketch to remove the left half of the

clip and complete the feature. When finished the clip should look

like the following figure.

Figure 2 The Symmetric Clip Cut in Half

Task 2. Create a datum point for the measure. One of your big concerns

is, for the given load, will the catch displace enough to clear the latch on

the mating part? You will now add a measure to track the displacement of

a point on the tip of the catch, but first you need to create the datum point

at the point of interest.

1. Create a datum point as shown in the following figure.

� Click [Insert a datum point].

� Select On Vertex.

� Click the vertex of the catch to create the point, as shown in the

following figure.

� Click Done Sel > Done when finish.



NOTES

Figure 3 Create a datum point at the tip of the catch.

Task 3. Create a Region in Pro/MECHANICA to apply the load. The

load on the tab will be applied by a finger pressing on a localized area

represented by a region.



2. Create surface region for load. Click Model > Features > Surf

Region > Create > Sketch > Done.

3. Sketch the section of the region.

� Select the top surface of the tab as the sketching plane.

� Select Bottom and select DTM3 as the reference plane.

� Specify the appropriate sketching references and draw a

horizontal line across the tab as shown in the following figure.

� Dimension the curve 6.35 from the edge of the tab.

� Click [Done] to finish.

4. Select the top surface of the clip, where the sketch resides on, to

split. Click Done Sel > Done > OK.

5. Verify the created region.

� Click View > Model Setup > Mesh Surface.



NOTES

� Click the region. The region should appear as shown in the

following figure.

Figure 4 Create the Region

Task 4. Create the midsurfaces.


2. To create the surface pairs, click Idealizations > Shells >

Midsurfaces > Auto Detect.

3. Test the compression to verify a successful pairing. Click

Compress > Shells only > ShowCompress. The midsurfaces

model should look like the following figure.



NOTES

Figure 5 The Midsurface Clip

Task 5. Set the material properties.

1. Assign NYLON material properties to the clip.

2. Edit the NYLON properties to assign values for failure criteria.

� Click the Failure Criterion tab in the MATERIAL DEFINITION

dialog box.

� Select the Distortion Energy (von Mises) option from the

drop-down list. Enter [85] for the TENSILE YIELD STRESS.

Note:

The tensile yield strength entered does not affect the

calculations that Mechanica makes during the analysis. The

purpose of this value is to provide a more convenient option

for plotting stress results.

� Select [N/mm^2] for the units of the tensile yield strength.

Task 6. Define the constraints.

1. Apply a symmetry constraint to the model.

� Select the 5 edges shown in the following figure.

� Constraint the X translational dof, Y and Z rotational dof on

the plane of symmetry. Free other dofs.

2. Create a second constraint. The clip is glued to the appliance at the

flange location. Fix all dofs of the bottom surface of the flange,




NOTES

Constraint these edges

Constraint this surface

Figure 6 Constrain the clip.

Task 7. Define a surface load to simulate a finger pushing on the tab.

1. Apply a 1.25 N surface load (half of the total load, due to the

symmetry), in the negative Y-direction on the created region. After

the load is applied, the model should appear as shown in the

following figure.

Figure 7 Apply a surface load.

Task 8. Define the measures. Because the tip of the catch must clear a 7

mm latch, you will want to track the displacement at the bottom of the

catch with a measure.

1. Define the measures. Click Model > Measures.

2. Pro/MECHANICA informs you of the coordinate system that the

measure will reference. Click OK.



NOTES

3. Enter [Y_disp_clip_tip ] for the measure name.

4. Select Displacement for QUANTITY.

5. Click Select/Review and select PNT0.

6. Accept other defaults and close the dialog boxes.

Task 9. Create and run a static analysis.

1. Create a static analysis called CLIP_STATIC.

� Click Analyses from the STRC MODEL menu.

� Leave Static as the TYPE and click New.

� Enter [clip_static ] as the name. Accept all the defaults and

click OK> Close.

2. Click Done/Return > Settings and verify that Use Pairs is

selected.

3. Run the structure analysis.

Task 10. Checking the results.

1. Examine the summary file and the key statistics regarding the

model, such as the number of elements, the elapsed time, and

required disk resources.

2. Look for maximum von Mises and principal stresses, maximum

displacement, resultant loads, and error estimates.

� Did the run complete without any errors? ________

� What is the value for Y_disp_clip_tip? ___________mm

Task 11. Display and interpret the results.

1. Create an animated result window to display the displacement

fringe plot.

2. Create an animated result window to display the von Mises Stress

fringe plot. Notice that the high stress area is near the inner tab

fillet area.



NOTES

Task 12. Create a Failure Criteria results window.

1. Create a failure index result window by copying the stress window.

� Enter [failure_index ] as the name.

� Select Failure Index as the QUANTITY.

� Unselect Animate.


2. The results indicate that the failure index is below 1.0 for the entire

model. This means there are no areas in the model where the

stresses will surpass yield stress of the material.

3. (Optional) Set the color legend to display the area that is above 1

in red. The model should have no red spot.

4. Exit the result window interface.

Task 13. Define design parameters. Design Parameters change the shape

of the model within a specified range during a sensitivity or optimization

design study.

1. Create the Design Parameters. Click Model > Dsgn Controls >

Design Params > Create. The DESIGN PARAMETER

DEFINITION dialog box appears.

2. Select the design parameter.

� Leave the TYPE as Dimension and click Select.

� Select the slot feature. Use Query Sel if necessary.

� The dimensions associated with the slot feature will then

appear. Select the R0.89 dimension. This dimension controls

the width of the slot.

3. Change the name to [slot_radius ].

4. Enter [0.8 ] for the minimum and [1.5 ] for the maximum. Click

Accept to complete the design parameter definition.

5. Repeat this process to create the design parameters shown in the

following table.



NOTES

Table 1: Design Parameters

Dimension Minimum Maximum

slot_length, d32 (orig=31.75) 19.05 44.45

slot_width, d50 (orig=7.62) 2.54 7.62

body_width, d51 (orig=20.32) 17.78 25.4

Task 14. Shape Animate the clip.

Note:

Use Shape Animate to vary the parameters across different

ranges and in different combinations, to anticipate problems

that might arise during the optimization process, and to make

sure the parameter ranges are causing the part to change as

intended.

Also, use Shape Review to review the model at specific

settings for each parameter and to identify conflicting design

changes within dimension ranges.

1. Click Shape Animate.

2. Select on all four of the design parameters, and set the NUMBER

OF INTERVALS to 2. Click Animate. When prompted, press

<Return> to continue.

3. The clip is regenerated at the initial and final configuration shown


Figure 8 Shape Animation



NOTES

4. When prompted to restore the model to its original shape, click

Yes.

Task 15. Shape Review the clip. Shape Review modifies the current

value of any or all of the design variables.

1. Click Shape Review.

2. Select all of the design parameters and click Review.

3. When prompted to restore the model to its original shape, click

Yes.



NOTES

EXERCISE 2: Running Sensitivity Studies

Task 1. Create a local sensitivity.

1. Click DesignStudies from the MEC STRUCT menu.

2. In the DESIGN STUDY DEFINITION dialog-box, enter [clip_ls ]

for the study name.

3. Select Local Sensitivity from the TYPE drop down list.

4. Verify that clip_static is selected.

5. Click Set Parameters and select all parameters by checking all

the check boxes next to the parameters.

6. Set the parameter values as shown in the following figure.

Figure 9 Define a Local Sensitivity Design Study.

7. Accept all the defaults. Click Accept > Done to finish.



NOTES

Task 2. Run the design study.

1. Click Run. Click Settings in the RUN dialog box.

2. Reuse elements from an existing study.

� Select “Use elements from an existing study” and click

Select.

� Select clip_static, followed by Accept > Accept.

3. Click Start. Use the summary file to monitor the process.

4. Pay attention to the run times, convergence behavior, and

information dealing specifically with local sensitivity.

Task 3. Review local sensitivity results. Create four result windows to

compare how much of an effect each of the four parameters is having on

maximum von Mises Stress.


2. In the result interface, click [Insert a result window].

3. Name the window [slot_rad_stress ].

4. Select the clip_ls results directory, and click Accept.

5. For the MEASURE select max_stress_vm, followed by Accept.

6. For the DESIGN VAR, select slot_radius, followed by Accept.

7. Clip Accept and Show the result window definition.

8. Copy the result window to create and display three more windows.

� The names are [slot_wide_stress ], [slot_len_stress ]

and [body_wide_stress ].

� Keep the max_stress_vm as the MEASURE.

� Select slot_width, slot_length, and body_width as the

DESIGN VAR respectively. Display all four windows.

9. By default, the four windows will all have different Y-axis scales.

To compare the four parameters, you will tie the graphs together.



NOTES

� Click the SLOT_LEN_STRESS window that has the largest Y-

axis scale.

� Click Utilities > Tie > Graphic Quantity and select another

window.

� Repeat for the other two windows. When finished, all graphs

should have the same Y-axis range.

Note:

The von Mises stress should always be non-negative.

The local sensitivity plot extrapolates the von Mises stress

over a parameter range, using the sensitivity at a specific

parameter value. Therefore, the graphs may indicate

“negative” von Mises stress.

Task 4. Create four windows to see the effect of the parameters on the

displacement measure Y_DISP_CLIP_TIP.

1. Copy the body_wide_stress window to [body_wide_y_disp ].

2. Change the MEASURE from max_stress_vm to Y_disp_clip_tip.

3. Blank all the von Mises stress windows.

4. Create and show other three windows by copying the

body_wide_y_disp window. Use the following result window

names, measures and design parameters:

� slot_wide_y_disp: Y_disp_clip_tip vs. slot_width

� slot_len_y_disp: Y_disp_clip_tip vs. slot_length

� slot_rad_y_disp: Y_disp_clip_tip vs. slot_radius

5. Tie all the Y-axes together.

6. Review the plots and determine the following information.

� Which parameter has the greatest effect on the tip's

displacement? _______________________

� Which parameter has the least, or perhaps no effect?

______________________



NOTES

7. The following observations can be made:

� The tip displacement is most sensitive to slot length and slot

width.

� Slot radius appears to have less effect.

� Body width has no effect at all.

8. The following conclusions are made:

� The slot length and slot width have a big impact on the

maximum von Mises stress and clip tip displacement.

� Slot radius has less effect.

� Body width has no effect on the maximum von Mises stress

and clip tip displacement.

� Since body width has no effect on any quantity of interest, it

will be excluded from future studies.

Note:

The calculated slopes are strictly relevant to the single

geometry state called for in the Local Sensitivity Study

definition form. The slopes will be different for differentcurrent values of your parameters.

9. Exit result interface when finished.

Task 5. Define and run a global sensitivity design study called CLIP_GS

to study the effect of slot_length over its range.

1. Click DesignStudies > Create.

2. Enter [clip_gs ] for the design study name. Select Global

Sensitivity for the TYPE.

3. Verify that clip_static is selected.

4. Select slot_length and unselect all other parameters.

5. Change the NUMBER OF INTERVALS to 4.

6. Verify that Repeat P-Loop Convergence is selected. The dialogbox should appear as shown in the following figure.



NOTES


Figure 10 Define a global sensitivity.

8. Run the global sensitivity study clip_gs. Monitor the process using

the SUMMARY file.

Task 6. Review the global sensitivity results. Look at sensitivity plots of

mass, von Mises Stress, and tip displacement versus the slot length

parameter.

1. Create a results window:

� Name the window [slot_len_mass ], referencing the clip_gs

design study.

� Select clip_static analysis.

� Select total_mass for the MEASURE and slot_length for the

DESIGN VAR.

2. Create and show three more windows by copying the

slot_len_mass window. Use the same DESIGN VAR slot_length.

� Name: slot_len_vm; MEASURE: max_stress_vm

� Name: slot_len_disp; MEASURE: Y_disp_clip_tip



NOTES

� Name: slot_len_maxd; MEASURE: max_disp_mag

3. The following observations can be made from the result windows:

� Increasing the slot length decreases mass.

� Increasing the slot length also increases maximum

displacement and the clip tip deflection

� Increasing the slot length increases the maximum stress.

4. The observations above will help us prepare the optimization,

where our goal is to find the value for the slot_length that

decreases stress, and mass, and results in a clip tip deflection

between 7 mm and 9 mm.

5. Exit result interface when finished.



NOTES

EXERCISE 3: Optimizing the Clip

Task 1. Define an optimization.

1. Click DesignStudies from the MEC STRUCT menu.

2. Click Create and enter [clip_opt ] as the name.

3. Select Optimimization for the TYPE.

4. Define the GOAL: Minimize max_stress_vm.

5. Define the LIMITS: Y_disp_clip_tip > 7, Y_disp_clip_tip < 9,

and total_mass < 2.2e-6.

Note:

When the unit system is mmNsec, the mass unit is a metric

tonne.

6. Define the parameters that will be used in the optimization. Check

the check boxes next to the slot_radius, slot_length and

slot_width parameters.

7. Since the parameter body_width does not impact stress or

displacement as seen in the local sensitivity analysis, make sure the

check box is CLEARED. You may have to scroll through the

parameter list.

8. Define the parameter initial values. Set all parameters (except

body_width) to the middle numeric value.

9. Converge to 2% with a max number of iterations of 20. Verify that

Repeat P-Loop Convergence is selected.

10. The dialog box should look like the following figure. Click Accept

> Done when finish.



NOTES

Figure 11 Optimization Study Definition

Task 2. (Optional)Run the optimization.

1. Run the optimization. Monitor the process using the summary file.

2. Alternatively, you can retrieve the provided result to save time.

Task 3. Create four result windows showing the optimization history of

displacement, tip displacement, von Mises stress and mass.

1. If you have run the optimization, use those results to create result

windows. Otherwise, use the results provided to create result

windows. Consult the instructor for the “stored results” location, if

necessary.

2. Create the following result windows to display the measure

variation vs. Iteration during the optimization.



NOTES

� NAME [vm_opt_pass ]; MEASURE: max_stress_vm

� NAME [disp_opt_pass ]; MEASURE: Y_disp_clip_tip

� NAME [mass_opt_pass ]; MEASURE: total_mass

� NAME [maxd_opt_pass ]; MEASURE: max_disp_mag

3. Examine the windows.

� The results show the measure variation during the

optimization. Notice the maximum von Mises stress changes

from 66 M Pa to approximately 50 M Pa.

� The optimized model satisfies all constraints.

� As Pro/MECHANICA approaches the optimal shape, the

values for stress, displacement, and mass stop fluctuating; and,

as soon as all of the values are within 2% of the goal and

limits, the optimization is complete.

Task 4. Create result windows for von Mises and displacement stress

fringe animations.

1. Create von Mises stress fringes without animation.

2. Click Info > Model Max to display the maximum von Mises stress

on the model.

3. Create an animated displacement result window. Review the

results window carefully.

4. Exit the result interface when finished.

Task 5. Update the current part design dimensions to those of the

optimized design.

1. Click Model > Dsgn Controls > Optimize Hist > Search Study.

2. Select clip_opt from the list. Pro/MECHANICA begins an

animation of the shape changes.

3. Click <Return> when prompted to review the next shape.

4. Click <Return> to confirm when prompted to leave the model at

the optimized shape.



NOTES

5. Compare the original design to the new one. In the original design,

the catch displacement was not sufficient to clear the latch, the

stresses were higher, and it was heavier. The new design has

sufficient displacement, less stress, and is lighter.




NOTES

MODULE SUMMARY

You have learned:

• How to run local sensitivity and global sensitivity studies tounderstand the effects of shape change on the model.

• How to run an Optimization Study and replace the Pro/ENGINEERpart with the optimized shape that Pro/MECHANICA developed.


1

Module

Running AnalysesIn this module, you will apply all you have learned to analyze and

optimize a plate-with-a-hole part.

Objectives

After completing this module, you should know how to:

• Define and run static analyses.

• Create design parameters.

• Define and run global sensitivity studies.

• Define and run optimization studies.


2 Fundamenta ls of MECHANICA STRUCTURE/THERMAL

NOTES

Model Description

The part is a 10 x 10 x 0.125” steel plate, with a 2” diameter hole through

its center. The hole can move along a 45° line from the upper left hand

corner, 2” from each edge, to the lower right hand corner, 2” from each

edge. The plate is subjected to a tensile load of 10,000 lbf on its vertical

sides. The model is shown in the following figure.

Figure 1: A Plate with A Hole

Task 1. Perform a static analysis on the design.

1. Perform a static analysis on the design as it exists. Your instructor

will review your results and modeling technique with you.

Task 2. Create a design parameter.

1. Create a design parameter to move the hole along the 45° line.

Task 3. Run a global sensitivity study.

1. Run a global sensitivity study to learn how von Mises stress is

affected by the hole’s location.

2. Record the hole location for minimum stress. Show your

instructor the results.

� Hole Location for Minimum Stress _______________


Running Analyses Page 10-3

NOTES

Task 4. Define and run an optimization study.

1. Define and run an optimization study to find the hole location that

minimizes von Mises stress.

� Test the optimizer by starting the optimization far from the

minimum value determined in the global sensitivity study. Start

the optimization with the hole’s design parameter value at

minimum of its range.

� Record the hole location for minimum stress. Show your

instructor the results.

� Hole Location for Minimum Stress ________________


1

Module

Advanced ExercisesIn this lesson, you will work with additional exercises to help further

your development in Pro/MECHANICA.

Objectives


• Describe the purpose of spot-welding.

• Desiree the purpose of contact analysis.

• Desiree the purpose of transient thermal analysis.

• Desiree the purpose of large deformation analysis.



NOTES

INTEGRATED MODE CONTACT FUNCTIONALITY

You can use contact analysis to solve design problems where parts come

into contact, but the exact regions that touch are unknown. Examples of

these parts are rollers pressing against each other, press fits, rotating gears

or shaft assemblies. Contact analysis is applicable whenever the model

stiffness or load path changes as a function of the applied load.

Before running a contact analysis, you first must define contact regions.

Contact regions indicate which curves or surfaces may touch during a

contact analysis. Pro/MECHANICA ignores contact regions for analysis

types other than contact. Additionally, contact regions are frictionless and

will only transfer normal forces.

When running a contact analysis, Pro/MECHANICA calculates the

detailed stress gradients and deformations found in contact regions that in

some cases may cause the part failure. Determining stresses and

deformations in a contact analysis is a non-linear problem requiring an

iterative solution scheme. The non-linearity is due to the contact area

varying non-linearly with the applied load.

Pro/MECHANICA uses advanced P-element technology and geometric

elements with a penalty solution method for achieving a converged contact

solution. This procedure is fully adaptive and automated and requires no

artificial constraints such as the gap elements used in conventional finite

element codes.

Running Contact Analyses

Contact analysis in Pro/MECHANICA is considered frictionless; the

interface in contact is assumed to be perfectly lubricated.

When using contact analysis on your own models, you should be aware of

the following limitations:

• You cannot use enforced displacements on contact regions.

• You can only run standard or global sensitivity design studies andoptimization with a contact analysis; local sensitivity design studies

can not be run.

• You can not use the iterative solver.

• You cannot combine results from two load sets.


Advanced Exerc ises Page 11-3

NOTES

• The contact solution is computed for solid elements only.Pro/MECHANICA will not create contact regions on surfaces with

shell or beam elements.

Pro/MECHANICA Structure handles moderate displacements and

rotations. These displacements and rotations are small enough so that the

Small Displacement Theory is adequate for element calculations, but large

enough that significant rotation of element normals or significant relative

tangential motion of the two surfaces of contact occurs. For 3D models,

the allowable inter-penetration tolerance is one-half the minimum “length”

of the two surfaces defining a contact region, where “length” represents

the square root of the surface area.

Defining Contact Regions

You can define the contact regions manually or automatically. However, if

you use the automatic option, and the assembly is complex (many possible

contact surfaces), some contact regions that are not needed may be

defined. To prevent longer run times, you should delete the excess contact

icons. For a complex model, this can be cumbersome, thus, use this option

with care.

Defining Contact Analysis Measures

There are two default global measures that are calculated for every contact

analysis:

• contact_area: Sums the total area of all the contact regions in themodel.

• contact_max_pres: Tracks the maximum pressure in any of thedefined contact regions.

You can also set up user-defined measures to track five attributes of a

single contact region. These are very helpful when your assembly contains

multiple contact regions:

• Contact area • Maximum contact pressure

• Average contact pressure • Contact load

• Force



NOTES

Setting Contact Analysis Options

The following options are available when defining contact analyses.

Specifying Load Increments

For contact analyses, you can enter a value for the Number of Load

Increments which specifies the steps at which Pro/MECHANICA

calculates results. This enables you to see how measures vary with the

load. This is similar to performing a global sensitivity with a design

parameter on the load (if that were possible in Structure).

You will use the default of 1 for number of load increments. This option

tells Pro/MECHANICA how to apply the loads or enforced displacements

to the model incrementally. You can set the number of load increments to

more than 1 if you want to view any contact measures as a function of the

applied load. For example, use a value larger than 1 if you need a plot of

contact area vs. applied load.

In conventional FEA (h-codes), the contact solution accuracy is dependent

on the load increment. Pro/MECHANICA, on the other hand, gives you

solution accuracy regardless of what load increment you specify.

Refining the Localized Mesh

Localized Mesh Refinement is available for achieving accurate contact

pressures in the model.

If Localized Mesh Refinement (often called h/p adaptive refinement) is

selected, the mesh will automatically be refined near the contact region to

improve the pressure accuracy. However, Localized Mesh Refinement

does increase analysis run time.

Contact analyses are run for a variety of reasons. One reason to define a

contact analysis is to calculate stresses at an interface of two parts that are

contacting each other. Another reason to run a contact analysis is to

accurately simulate the load transfer between parts, where the maximum

stress in the model is not at the contact zone. For this type of analysis,

localized mesh refinement is not needed, and should be turned off to save

run time.



NOTES

TRANSIENT THERMAL ANALYSIS

For engineering processes that involves heating and cooling, the

transitional period of time is of great interest. The analysis must be

modified to take into account the change in internal energy of the body

with time. In Pro/MECHANICA, this type of data is obtained through a

Transient Thermal analysis.

Fundamentals

When evaluating a design, you may need to investigate what will take

place between material bodies as a result of a temperature difference. This

energy transfer between two bodies (commonly referred to as heat) may

be considered in steady-state or in a transient state.

Thermodynamics deals with systems in equilibrium - it may not be used to

predict how fast a change will take place. Systems in equilibrium are

considered to be in steady-state.

Heat transfer is used to predict the rate at which this exchange will take

place under specified conditions. Bodies not in equilibrium are considered

to be in a transient phase.

Transient Heat Transfer

When bodies are suddenly subjected to a change in environment, some

time may elapse before an equilibrium temperature condition will exist in

the body. Until then, the body is in an unsteady state.

Many engineering problems are concerned only with the steady-state heat

transfer of a part or assembly. This type of information can be obtained by

running a Steady-State Thermal analysis in Pro/MECHANICA.

However, for engineering processes that involve heating and cooling, this

transitional period of time is of great interest as well. The analysis must be

modified to take into account the change in internal energy of the body

with time. In Pro/MECHANICA, this type of data is obtained through a

Transient Thermal analysis.

Whenever there exists a temperature difference in a medium or between

media, heat transfer must occur. This exercise deals with two modes of

heat transfer: conduction and convection.



NOTES

Thermal Conduction

Conduction is the heat transfer mode that occurs when a temperature

gradient exists in a stationary solid or fluid. Conduction is the transfer of

heat through materials without net mass motion of the material.

The general equation for heat transfer by conduction is:

q =-kA dT/dx where:

q is the rate of heat flow in x-direction

k is the thermal conductivity

A is the area normal to x-direction through which heat flows

dT/dx is the temperature gradient in the x-direction

dT is the temperature change in the x-direction and dx is increment in

length in x-direction

Thermal Convection

Convection is the heat transfer mode that occurs between a surface and

moving fluid when they are at different temperatures. It is the process inwhich thermal energy is transferred between a solid and a fluid flowing

past it. The general equation for heat transfer by convection is:

q = hA ∆T

where:

q is the rate of heat flow via convection

h is the heat-transfer coefficient (also known as the film coefficient)

A is the surface area through which heat flows (convection area)

∆T = Tw -T∞, (temperature potential for heat flow away from surface)

Tw is the wall (surface) temperature and T∞ is the bulk temperature

(average fluid temperature far away from wall)



NOTES

Defining the Measures

The Transient Thermal analysis has three default measures that are

evaluated over the model at each time step. They are:

• min_dyn_temperature

• max_dyn_ temperature

• max_ flux_ mag

Any information that you want graphed against time, other than these

measures, has to be specified as a user-defined measure before an analysis

is run.

The options for Quantity are:

• Temperature

• Heat Flux

• Temperature Gradient

• Driven Pro Parameter

• Time

The options for Spatial Variation are:

• At Point

• Max Over Model

• Range Over Model

• Min Over Model

• Max Abs Over Model

The options for Time Evaluation are:

• At Each Time Step

• Maximum

• Minimum

• Maximum Absolute

• At Time



NOTES


Goal

To gain more experience with idealizations and analyses.

Method

In the first exercise, you will create and analyze the spot welded sub-

assembly. The overall stress in the sub-assembly can be determined, as

well as any excessive stress concentrations at the location of the spotwelds

In the second exercise, you will use Pro/MECHANICA to determine:1)

The stress on the mounting surface of the pin. 2) The values for the

contact area and contact pressure. 3) Any unreasonable hot spots in the

latch mechanism.

In the third exercise you will set up and run a transient thermal analysis.

In the fourth exercise, you will set up and run a large deformation

analysis.



NOTES

EXERCISE 1: Creating and Analyzing Spot WeldedSub-Assemblies

Overview

A spot weld consists of a beam that is fused to a surface over an area

defined by the diameter of the weld. You can use spot welds to model

welded structures and bolted connections. When you use spots welds, you

must specify both the diameter of the weld and the material. The length of

the weld is determined by the location of the fusion points on each surface.

Spot welds can be used in both part mode and assembly mode, but patterns

and zero-length spot welds are not supported.

In this lesson, imagine the following scenario. You are the lead engineer

for a company that makes motor-controlled robots for picking up heavy

objects. Due to marketing demands, engineering has decided to use a

heavier, more powerful motor. The current motor rests in a u-channel that

is spot welded to an electronics barrier shelf. This shelf then slides into the

framework of a larger assembly. The team you are working with is

worried that the added weight of the new motor will cause excessive

deflection in the u-channel (the new motor weighs 1000 N). A deflection

of more than 2.54 mm would cause the motor to come in contact with the

lower level of the assembly. For this reason, they want to move to a

continuous seam weld instead of spot welds. From a labor point of view,

that option is very expensive and your boss wants you to make sure it is

absolutely necessary.

The motor has a 152 mm x 406.4 mm base attached to the bottom of the

U-Channel. The four spot welds are placed at 152.4 mm intervals between

them. Because the parts are thin, you will define the assembly as a shell

model. The spot welds are 25.4 mm diameter and 6.35 mm long.

Task 1. Define the surface pairs in part mode to model the assembly as

a shell model.



2. Open the SPOT_WELD.ASM. The units are mmNs. Notice the

there is a 6.35 mm gap between the parts.



NOTES

3. Enter Pro/MECHANICA Structure to test the sheet metal

compression. Notice no midsurfaces have been defined.

Note:

Recall that when simulating an assembly as a shell model, the

midsurfaces have to be defined at the part level.

4. Open the part U_CHANNEL.PRT. Enter Pro/MECHANICA

Structure. Auto-detect and compress the surface pairs. Save the

part and close the window.

5. Repeat the procedure to compress the SHELF.PRT.

Task 2. Idealize the assembly as a shell model. Assign material

properties.

1. Switch to the assembly window.



3. Compress the surface pairs. Click Model > Idealizations > Shells

> Midsurfaces > Compress > Shells only > ShowCompress.

4. Return to the STRC MODEL menu when finished.

5. Assign STEEL as the material for both parts.

Task 3. Create the spot welds.

1. Click Idealization > Spot Welds > Create.

2. Define the references.

� For the first surface, select the bottom surface of the shelf to be

welded.

� For the second surface, select the top right flange surfaces of

the U channel.

� For the points, select the 4 datum points on the right side of the

shelf and the 4 datum points on the right side of the U channel.

� Click Done Sel to finish.

3. Define the weld diameter. Enter [25.4 ].



NOTES

4. Assign STEEL as the material for the spot welds when prompted.

The system displays the spot weld icons.

5. Repeat the steps above to create spot welds on the left-hand side.

Task 4. Define the boundary conditions. The surface regions for the

boundary conditions have already been defined for your convenience.

1. Create a surface constraint to represent the slot that clamps the

edges of the shelf.


� Enter [slot ] as the name.

� Select the two surface regions that represent the clamp area on

the shelf part, as shown in the following figure.

� Fix all 6 DOFs.

2. Create a load to simulate the motor.

� Click [Create a surface load].

� Enter [motor ] as the load name.

� Select the rectangular surface region on the bottom of the U

channel.

� Enter [-1000 ] as the FORCE component in the Y direction.

Figure 1: Assembly With All The Boundary Conditions And Spot Welds Defined



NOTES

Task 5. Create and run a static analysis.

1. Define a static analysis named [spot_weld ]. Accept all the

defaults.

2. Run the spot_weld analysis.

3. A confirmation window warns that there are originally 2 disjoint

bodies in the model. They should be properly connected by spot

welds. Click Confirm to proceed.

Task 6. Display and interpret the results.

1. Create and show a displacement result window. Note the

maximum displacement in the model.

Figure 2: Displacement Fringe Plot

2. Create and show a von Mises stress result window. Note the

maximum stress in the model.



NOTES

Figure 3: Von Mises Fringe Plot

3. Do the spot welds create any excessive stress concentrations on the

shelf?



NOTES

EXERCISE 2: Contact Problems

Overview

The following figure shows a latch mechanism used to secure a small

electronic box on an airplane. When the front compartment door to this

box is closed, the latch is subjected to a horizontal force of 400 N. Further

movement is prevented when it comes into contact with a pin that is

completely fixed to the interior skin of the aircraft.

As an engineer, you are concerned about stresses on the mounting surface

of the pin due to this contact. In addition, you want to check for any

unreasonable stresses in the latch or pin due to the contact pressure.

Finally, some of your team thinks the mechanism is over designed and that

mass should be taken out of the latch.

Figure 4: Latch Mechanism

Task 1. Retrieve the latch model and enter MECHANICA.

1. Open LATCH.ASM. Verify that the units are mmNs.



Task 2. Assign STEEL as material for both parts.

1. Click Materials. Add STEEL to the model.



NOTES

2. Click Assign > Part. Select both parts, followed by Done Sel.

3. Click Close when finish.

Task 3. Constrain the latch assembly.

1. Constraint the bottom of the latch so that the latch can only move

freely in the x-direction.


� Select the bottom surface of the latch as shown in the following

figure.

� Free translation in x-direction. Fix all other DOFs. Click OK to

finish.

Figure 5: Latch Surface Constraint

2. Constrain the back of the pin.


� Select the back surface of the pin as shown in the following

figure.

� Fix all 6 DOFs. Click OK to finish.



NOTES

Figure 6: Pin Surface Constraint

Task 4. Apply the load.

1. Apply a load of 400 N in the x direction as shown in the following

figure.

Figure 7: Surface Load



NOTES

Task 5. Define the contact regions.

1. To define a contact region, click Model > Contacts > Create >

Face/Surface.

2. Select the surfaces that may be in contact (meshed in the following

figure).

3. Click Done Sel. Note that the contact icon appears.

4. Review the contact region.

� Click Review.

� Click the contact icon. The system highlight surfaces in red.

Figure 8: Contact Region Surfaces

Task 6. Define the measures.

1. Set up any relevant measures you need for this analysis. Two

contact measures are automatically defined for the contact analysis

pressure area.

Task 7. Define the contact analysis.

1. Click Analyses > Static > New.

2. Enter [contact_spa ] as the name.



NOTES

3. Click the Convergence tab.

� Make sure the Convergence Method is Single-Pass Adaptive.

� Select Localized Mesh Refinement.

� Click OK > Close.

4. Run the CONTACT_SPA analysis.

5. Confirm when prompted for error checking.

6. Click Confirm when system warns that there 2 disjoint bodies in

the model. Since there is a contact region defined between the 2

bodies, the model is sufficiently constrained.

7. Monitor the process using the summary file. Notice that the

Pro/MECHANICA recognizes the contact area is small and

automatically refines the mesh in that area.


1. Create and display an animated displacement fringe plot. Verify

that the loading is causing the latch to come into contact with the

pin. Note that the latch may appear to pass through the pin. This

happens because the magnitude of the displacement is magnified

(scale factor).

Figure 9: Displacement Result Window

8. Create and display a non-animated von Mises stress fringe plot.

Edit legend scale for clearer display as necessary.



NOTES

Figure 10: Von Mises Stress Fringe Plot

9. Notice that the contact area is very small. Is this an effective latch

mechanism? From the stress level, you can conclude that the latch

mechanism is over designed.

Task 9. The values at the mounting surface are reasonable. However, if

the team makes design changes to reduce mass in the mechanism, these

stress concentrations could pose problems. Take a closer look at the

contact area and pressure on the latch.

1. Create a cutting surface to look at the inside of the model.

� Click Insert > CuttingSurfs.

� Accept the default WCS as well as the XY plane.

� Enter [30%] for the cutting depth.


10. Dynamically modify the cutting plane.

� Click Edit > Cutting Plane.

� Click the Dynamic option.

� Drag left mouse button to move the cutting plane.

� Click the middle mouse button to finish.




NOTES

Figure 11: Stress Inside Of The Model Using The Cutting Plane

11. Exit the results interface.




NOTES

EXERCISE 3: Running Transient Thermal Analyses

Overview

The following figure shows a rocket-engine nozzle for a prototype shuttle

between Earth and the new Space Station. At the time of ignition, this

nozzle will be subjected to hot gases at 1648.8 °C. The gases combine and

reach their maximum temperature over time.

The part is coated with a ceramic material having the following properties:

Thermal Conductivity k=10,781 W/m o

C

Specific Heat c=1.624 kJ/kgoC

Density ρ=4.52 103 kg/m

3

The convective heat-transfer (film) coefficient between the nozzle and the

gases is 4 103 kW/ m

2 oC . The nozzle is initially at –17.7

oC.

Figure 12 A Rocket-Engine Nozzle Prototype

Your job as engineer is to determine if the rocket's engine is on too long

before launch, thus, over-heating the nozzle. The engine is on for 100

seconds before lift off. There is an electronic warning switch located on

the inner surface of the nozzle that will alert launch control if the nozzle

temperatures are higher than 1371°C. In addition, you need to ensure that

the temperature gradients in the coating are not too large during the initial



NOTES

start-up. There can be no more than a 400°C difference between the inner

and outer surfaces of the nozzle. Finally, the thermal protection engineerswould like to correlate data with your analysis and have asked you to

provide complete temperature profiles for two points during the count-

down; one half-way through ignition (50 seconds), and one right before

lift-off (100 seconds). You will use Pro/MECHANICA to determine:

• How long after start up will it take for the temperature on the ceramic

coating's surface to reach 1371°C.

• If there are any large thermal gradients during ignition that mightcause the ceramic coating to crack.

• What the temperature profile looks like half-way through ignition andright before lift-off.

Considerations for Transient Thermal Analyses

Some issues to consider when using Transient Thermal Analysis in

Pro/MECHANICA are as follows:

• The model cannot contain multi-point constraints.

• It is available for 3D models with isotropic elements only (noshells/beams).

• It is available for standard analyses only (no sensitivity oroptimization).

The time dependence is a multiplier function, so the user can only enter

loads that also have a spatial variation as the product of two functions. For

example:

f(x,y,z) * f(time)

NOT f(x,y,z,time)

Task 1. Retrieve the model and assign the material properties.

1. Open NOZZLE.PRT. Note that the unit system is mmNs.

2. Enter the Pro/MECHANICA Thermal module.

3. The material properties of the ceramic file and the convection

coefficient are as follows:

� Thermal Conductivity k=10,781 W/m o

C



NOTES

� Specific Heat c=1.624 kJ/kgoC

� Density ρ=4.52 (103) kg/m

3

� Young’s Modulus E = 400,000 N/mm^2

� Convection Coefficient h = 4 (103) kW/ m

2 oC

Using the units found in the strategy guide, the above information can

be converted as follow:

� Specific Heat Capacity c = 1624 m^2/sec^2C

� Thermal Conductivity k =10781 N/secC

� Density ρ== 4520 kg/m^3

� Convection coefficient h = 4000 mW/mm^2C

� Young's Modulus E = 400,000 N/mm^2

4. Create a new material named CERAMIC and assign the material

properties to the part using the information shown above.

Task 2. Apply the convection boundary conditions with a variable bulk

temperature. The gasses flow in at a rate such that temperature values per

unit of time are defined in a text file..

1. Click [Surface convection condition]. The CONVECTION

CONDITION dialog box appears.

2. Enter [flame ] for the name.

3. Accept the default constraint set.

4. Click [Select]. Select the inside nozzle surface, followed by

Done Sel.

5. Enter [4000 ] for the CONVECTION COEFFICIENT.

6. Enter [1] for the BULK TEMPERATURE.

7. Select the Time Dependant option.

Note:

In this case, the Bulk Temperature is only a factor. The actual

time dependent temperature is defined in the next step.



NOTES

8. Select Time Dependent > f(x).

9. Select Table from the TYPE drop-down list.

10. Click Import and retrieve the CONVECTION.TXT located in the

current directory.

11. Review the graph.

12. Finish the definition.

Task 3. Define and run a Transient Thermal analysis.

13. Click Analyses.

14. Choose Transient Thermal from the NEW ANALYSIS drop-down

list and name the analysis NOZZLE_THERM.

15. Name the analysis [nozzle_transient].

16. Select the constraint set.

17. On the Temperature tab, enter [-17.7 ] as the initial temperature.

18. On the Output tab,

� Select calculate Heat Flux.

� Choose User-defined Output Intervals.

� Set the number of Master Intervals to 3.

� Select the User-defined Steps button.

� For Interval 0, enter 0 seconds; for interval 1, enter 50 seconds;

for interval 2, enter 100 seconds; for interval 3, enter 120

seconds. Check the Full Results box next to each interval.

19. Click OK > Close to finish.

20. Run the analysis. Monitor the process using the summary file.

Task 4. Review the results.

1. Create a graph for max_dyn_temp measure vs. time. The result

window should appear as shown in the following figure.



NOTES

2. Using the following graph, determine at what time the nozzle

reaches a temperature of 1371 °C: ____________ . Is it prior tolift-off (100 seconds)? _______________

3. Create a temperature gradient fringe plot at 50 and 100 seconds.

Does the temperature gradient exceed 400 degrees C anywhere in

the model?

4. Create a temperature distribution fringe plot at 50 and 100 seconds.

This fringe plot could be used to correlate to experimental data.

5. Exit the results interface.


Figure 13: Maximum Dynamic Temperature vs. Time



NOTES

EXERCISE 4: Analyzing Large Deformation

Overview

The following figure shows an implant for an eye. As an engineer, you

are concerned about stresses and displacement around the tips of the

implant.

Task 1. Investigate the symmetric model.

1. Retrieve the EYE_IMPLANT.PRT located in the current

working directory.

2. The model is cut in half to take advantage of its symmetry.

Investigate the last cut by redefining it.

Figure 14: Symmetric model of Implant

3. Quit redefining without changing anything.



INFO dialog box.


3. Click Model > Materials.

4. Select Nylon from the MATERIALS IN LIBRARY.

5. Add the Nylon to the model.

6. Click Assign > Part.



NOTES

7. Select the eye implant part, followed by Done Sel.

8. Close the MATERIALS dialog box.

Task 3. Create a constraint for symmetry

1. Click Constraints > New from the CONSTRNTS menu followed

by Surface.

2. Enter [symmetry ] as the constraint name.

3. Click the [Select] icon under SURFACE(S) and select the cut

surface as shown in the following figure.

Figure 15: Surface for Symmetry Constraint

4. Click Done Sel to finish.

5. Click the [Select] icon under COORDINATE SYSTEM and

select the locate coordinate system CS1 previous created, as shown


Figure 16: Coordinate System for the Symmetry Constraint

6. Fix Z Translation and choose Free for all the DOF's. The data form

should look like the following figure.



NOTES

Figure 17: Symmetry Constraint Data Form


Task 4. Create a constraint on bottom of the implant.

1. Click New from the CONSTRNTS menu followed by Surface.

2. Enter [eyeball ] as the constraint name.

3. Click the [Select] icon under SURFACE(S) and select the

bottom surface as shown in the following figure.

Figure 18: Eyeball Surface Constraint



NOTES


5. Change the coordinate system to the World Coordinate System by

selecting WCS from the SIM CSYS SEL menu.

Figure 19: WCS for the Eyeball Constraint

6. Fix X, Y, Z Translation and choose Free for all the DOF's. The

data form should look like the following figure.

Figure 20: Eyeball Constraint Data Form


Task 5. Create a load at the end of the long segment

1. Click Loads from the STUC MODEL menu. Click New > Surface.



NOTES

2. Click the [Select] icon under SURFACE(S) and select the

surface region as shown in the following figure.

Figure 21: Tip Load Surface

3. Select the world coordinate system WCS from the SIM CSYS SEL

menu.

4. Select Total Load > Interpolated Over Entity from the

distribution drop down list.

5. Click Define to specify the interpolation points.

� Turn on the datum point display as necessary.

� Click Add in the INTERPOLATED OVER ENTITY dialog box.

� Select PNT0, PNT1, PNT2, as shown in the following figure.

Figure 22: Interpolation Points

� Click Done Sel > Done/Return when finish.

� Enter [1] for the second point and preview the load. The load

should look like the following figure. Click OK to finish.

6. In the FORCE/MOMENT data form, enter [-0.0008 ] as the Y

force component. The FORCE/MOMENT data form should look

like the following figure.



NOTES

Figure 23: Interpolation Points for the Tip Load

Figure 24: Tip Load Data orm


Task 6. Define a large deformation analysis.

1. Click Analyses. Accept the default Static from the NEW

ANALYSIS drop down list.

2. Click New to define a new static analysis. In the STATIC

ANALYSIS DEFINITION dialog box, accomplish the following

steps:

� Enter [large_def ] as the analysis name.

� Accept the default constraint set.



NOTES

� Accept the default load set.

� Check the Calculate Large Deformations check box under

the NONLINEAR OPTIONS.

� Accept the default Single-Pass Adaptive from the METHODS

drop down list on the CONVERGENCE tab.

� Click the LOAD INTERVALS tab, and examine the options.

You can use the Number of Intervals to run the analysis at

certain load intervals. To save time, accept the default interval

1.

� Click OK to close the STATIC ANALYSIS DEFINITION dialog

box.

3. Click Close to close the ANALYSES dialog boxes.

Task 7. Run the analysis.

1. Click Run from the MEC STRUCT menu.

2. Click Start in the RUN dialog box.

3. Click Yes, when prompted whether you want error detection.

4. Click Summary in the RUN dialog box and monitor the analysis

process.

5. When the analysis run is finished, close the summary window and

click Done to close the Run window.

Task 8. Create the result windows.




3. Create a window to display the displacement.

� Click Insert > Result Window.

� Name the result window DISPLACEMENT.

� Click the large_def\ in the CURRENT DIRECTORY.

� Click Accept.

� Fill out the data form as shown in the following figure.




NOTES

Figure 25: Definition for the Displacement Result window

4. Create a result window to display the stress using the same

procedure. Fill out the data form as shown in the following figure.

Click Accept to finish.



NOTES

Figure 26: Definition for the Stress Result Window.

Task 9. Display the result window and examine the results.

1. Click View > Display from the UNTITLED window.

2. Select both windows and click OK.

3. Select both windows. Press <Shift> key and click both windows.

The borders of both windows should be highlighted in yellow.

4. Play the animate. Stop when finished.

5. Notice there are only two frames for each result window. Had you

specified more intervals when you defined the analysis, there

would have been more frames generated for the result window.

6. Click File > Exit Results.

7. Choose No when prompted.



NOTES




NOTES

MODULE SUMMARY

You have learned:

• How to define spot weld idealizations.

• How to include contact regions in an analysis.

• How to define a transient thermal analysis.

• How to define a large deformation analysis.


1

Module

Fatigue AdvisorThis module presents the fundamentals of Fatigue Advisor, as well

as a tutorial demonstrating how to conduct a fatigue analysis.



NOTES

OVERVIEW

Pro/MECHANICA offers a tool called Fatigue Advisor, which can be

used to evaluate the potential of a model to fail due to fatigue damage. The

solving engine behind Fatigue Advisor is a product of nCode

International, a world leader in fatigue analysis. Through a partnership

between nCode and PTC, Fatigue Advisor is now accessible from within

the Pro/MECHANICA interface.

In general, fatigue may be defined as:

• Failure under a repeated or otherwise varying load, which neverreaches a level sufficient to cause failure in a single application.

• The initiation and growth of a crack or growth from pre-existing defectuntil it reaches a critical size.

As this definition suggests, to address the entire phenomenon of fatigue,

we must consider both the initiation and growth of a crack. The focus of

Fatigue Advisor is to predict the initiation of cracks. It uses a strain based

analysis (EN analysis) to predict this initiation. It does not address the

Linear Elastic Fracture Mechanics (LEFM) associated with crack growth.

The goal of Fatigue Advisor is to accomplish one of the following:

• Ensure an engineer that a particular model will not fail due to fatiguedamage throughout it’s desired life.

• Allow the engineer to optimize the model to eliminate fatigueproblems.

• Alert the engineer that, if the problems can not be eliminated throughoptimization, the model should be given to a fatigue expert for

additional attention.

To perform and analysis in Fatigue Advisor the following input is

required:

• Material properties (additional)– Ultimate Tensile Strength (UTS)

• A previously defined Pro/MECHANICA static analysis

• Load history information – characteristics of the loading

• Desired Life of the component

• Correction factors for surface treatment (optional)


Fat igue Advisor Page 12-3

NOTES

The results available from Fatigue Advisor are:

• Log life

• Log damage

• Confidence of life

• Factor of safety



NOTES


EXERCISE 1: Piston Fatigue

Figure 1: A Petrol Engine Piston

You are designing a petrol engine for a new range of small cars. It is a 4-

cylinder unit of 1100cc capacity with 90 ft.lb. torque. One of the

components that need analyzing is the new piston. Pistons have never been

known to fail through fatigue in the past but you are now required to prove

this before the component progresses to the next stage in the design.

Your colleague has provided you with Pro/ENGINEER geometry of ¼ of

the piston. The chief engine designer has estimated that each piston has a

force of 900 lbf. applied to the crown (i.e. 225 lbf. total on ¼ piston

model.) The material chosen is an aluminum alloy (details given in the

following table). The new engine has a target life of approximately

200,000 miles or 600 million cycles under a peak-to-zero loading.

Method

• Determine whether the piston is likely to suffer a premature fatigue

failure.

• Find the location that any cracks will start to form so the test engineerknows where to inspect after the tests are completed.



NOTES

• Determine the permitted factor of safety on load to determine howsensitive the piston is to overstress.

Table 1 Fatigue Parameters

Material Loading

Units lbf, in Desired Endurance 6e+008

Name AL2014 Load type Constant Amplitude

Material Type Aluminum Alloys Amplitude Type Peak-zero

Surface finish Polished Distribution Total load

Cut-off 2e+016 Force component Y = -225

UTS 70051

E 1.06e+007

µ 0.33

Kf 1

Goal

This is a typical example of an analysis where fatigue failure is not

expected but verification is still required. The piston will have to endure a

very high number of cycles; most fatigue analysis is only strictly valid for

less than 1E8 cycles. You will learn the following procedures:

• How to apply material fatigue properties to a Pro/MECHANICA solidmodel.

• How to apply fatigue load cases to the model.

• How to set up a static stress and fatigue analysis run.

• How to enable the Factor-of-Safety calculation using the Edit Session

option.

Task 1. Set the fatigue material properties.



2. Open PISTON.PRT and familiarize yourself with the model.


Continue > Structure. Notice that the model is properly

constrained for your convenience.

4. Assign material properties to the piston.



NOTES

� Click Model > Materials.

� Add AL2014 to the MATERIALS IN MODEL.

� Click Assign > Part.

� Select the piston part, followed by Done Sel.

5. Define the fatigue properties.

� Click Edit, and click the Fatigue tab.

� Enter the properties given in the previous table. The dialog box


� Click OK > Close to finish.

Figure 2: Fatigue Definition Form

Task 2. Define a surface load. The load simulates repetitive combustion

that causes fatigue.

1. Click [Create a surface load].

2. Enter [Combustion ] as the name.

3. Click [Select] under the SURFACE(S).



NOTES

4. Click the surfaces (meshed in the following figure) that make up

the piston crown.


Figure 3: Combustion Load Surfaces on Piston (shown meshed).

6. Enter [–225 ] as the Y force components.


Task 3. Setup a static analysis.

1. Click Analyses > Static > New.

2. Enter [piston_static ].

3. Accept the defaults. Click OK > Close to finish.

Task 4. Run the static analysis and display the result.

1. Run the analysis. Monitor the process using the summary file.

2. Create a result window to display the von Mises stress fringe plot.

3. Exit the result interface when finished.



NOTES

Task 5. Create a fatigue analysis.

1. Click Analyses and select Fatigue from the NEW ANALYSIS

drop-down list

2. Click New. Enter [piston_fatigue ] as the name.

3. Click the Load History tab. Enter the following information.

� Enter [6e8 ] for the DESIRED ENDURANCE.

� Select Constant Amplitude for the LOADING TYPE.

� Select Zero-Peak for the AMPLITUDE TYPE.

4. Click the Previous Analysis tab. Enter the following information.

� Check the Use static analysis results from previous design

study check box.

� Accept the default piston-static for both the DESIGN STUDY

and the STATIC ANALYSIS.

� Set the load to loadset1.

5. Set the PLOTTING Grid to 4. Click OK to finish.

Task 6. Run the analysis.

1. Run the piston_fatigue analysis. Monitor the process using the

summary file as it proceeds.


1. Create a result window for the piston_fatigue analysis to display

the Log Life plots.

2. Notice where the fatigue cracks is likely to form. The minimum

life is 1013.544

or 3.5E13, do you think this safety factor is OK?

3. Create a result window for the piston_fatigue analysis to display

the Confidence of Life plots.

4. Notice how the Confidence of Life is all green.



NOTES

5. Create a result window for the piston_static analysis to display

the animated von Mises stress plots.

6. Exit the result interface when finish.

Figure 4: Stress and Log Life Plots

Task 8. Enable the FACTOR OF SAFETY option and rerun the analysis.

The Factor of Safety option is switched off by default because it requires

longer run time. Had you created a Factor of Safety result window, the

value would be zero.

1. Turn on the Factor of Safety option using the session

configuration file.

� Return to the top-level menu. Click Configuration > Edit

Session.

� Add the keyword Fatigue_FOS_Calculation. Use <F4> as

necessary.

� Set the value to ON. Use <F4> to view options, as necessary.

� Click Exit when finish.

� Click Save Session As. Accept the default name.



NOTES

� Click Load File and load the saved file.

2. (Optional) Re-run the Fatigue Analysis. It could take long time

depending on the hardware. Alternatively use the results found in

the same directory generating the result windows.

3. Create and display a Factor of Safety result window.

4. View the Factor of Safety results. The minimum Factor of Safety

suggests a permissible overload of 2.8 times before the fatigue life

is jeopardized.

5. Change the legend for easier interpretation as necessary.

� Click Edit > Legend Value, and select the appropriate value to

edit.

� Use the FOS minimum (2.8 in this example) as the legend

minimum.

� Use around 10 times the minimum as the legend maximum.

6. Exit the result interface.




NOTES

MODULE SUMMARY

In this module, you learned how Pro/Pro/MECHANICA can be used to

calculate the fatigue life of a typical component.

• If this safety critical component were designed for a life of 10000cycles, would you pass this onto a fatigue expert or would you trust

this analysis?

• If you only required 5000 cycles what would you do?

• What is the value of Fatigue Advisor in this instance?


1

Module

Student ProjectsIn this module you measure your basic Pro/MECHANICA

Structure/Thermal knowledge.

Objectives


• Assign properties.

• Apply constraints.

• Define loads.

• Run static, thermal, and modal analyses.

• Modify the shape your part with design parameters.

• Use measures.

• Run sensitivity and optimization studies

• Evaluate your results.



NOTES

STUDENT PROJECTS

Each of the following design projects is outlined in detail. They vary in

degree of difficulty. Choose a project that most closely reflects you area of

interest.

• Flagpole • Driveshaft

• Wing spar • Valve Housing

• Heat Sink • Buckling Ring

• Beverage Can

Hints on how to design the projects are provided in the second half of the

module.

Designing a Flagpole

Design a horizontal flagpole, minimizing mass while keeping maximum

stress safely below yield.

The flag pole must be 4 meters long and extend in the z-direction. It must

be fully constrained at one end to represent the connection to the side of a

building. The other end must have a 100N downward load in the y-

direction representing the weight of the attached flag, and a 15N lateral

load in the x-direction representing wind loading on the flag (we can

ignore wind loading on the pole). Earthquake codes require that the pole

be able to carry 2G's worth of downward seismic loading in addition to the

regular 1G weight of the pole, for a total gravity load of 3G.

Build your model out of the "Steel" found in the Pro/MECHANICA

material library”, which is a general HS low-alloy steel. Shigley &

Mischke list the yield stress of 1212 Hot-Rolled steel to be 193 MPa. We

need a safety factor of 4 on this project. Choose a convergence value for

your static analyses of 10%, and an optimization convergence of 1%. Do

not build the model with beam elements, since we want very specific

stress information across the entire cross-section of the flagpole.

After validating that you've built a good model, incorporate design

variables on geometry and/or material properties to add design flexibility.

Optimize for minimum mass, while maintaining the other design criteria.

Any design with a total mass below 20 kg is acceptable, although there are

some designs with significantly less mass.


Student Pro jects Page 13-3

NOTES

No picture is shown because there could be many solutions to this

exercise. Your job is to find the one you think is the best and willing to put

into production.

Designing a Driveshaft

Design the lightest truck drive shaft that meets static and modal design

requirements.

You must design a 4 meter long driveshaft that is constrained at one end,

and has a 25,000 Nm axial torque at the other end. Although the loaded

end of the shaft is free to twist about its axis, for the purposes of looking at

realistic mode shapes, it should not be able to move radially or axially

since it represents the end of the shaft connected to the truck's

transmission. Due to packaging constraints, the shaft can have a radius no

greater than1 meter at any point.

The first mode of the shaft needs be greater than 60 Hz, so that engine and

ground terrain loading do not create destructive resonance in the shaft that

would shorten the shaft life.

Build your model out of the "Steel" found in the Pro/MECHANICA

material library, which is a general HS low-alloy steel. Shigley & Mischke

list the yield stress of 1212 Hot-Rolled steel to be 193 MPa. We need a

safety factor of 4 on this project.

Use sensitivity and optimization studies to find the design with the lowest

mass that meets these criteria. Choose a convergence value for your static

analyses of 10%, and an optimization convergence of 1%. Feel free to use

the single-pass adaptive algorithm where appropriate.

After you find the best design, run a pre-stress modal analysis to see if the

stress stiffness (and subsequent frequency of the first mode) is affected by

the torsion load.

No picture is shown because there could be many solutions to this

exercise. Your job is to find the one you think is the best and willing to put

into production.

Designing a Wing Spar

A Wing Support needs to be designed for low weight and displacement

resilience. The loads have been derived from wind tunnel experiments and



NOTES

have been given to the engineer as a boundary condition for the problem.

Stresses for fatigue failure are also a concern in the design.

Create the part as a shell model, using surfaces to represent the mid-plane

geometry. The part dimensions, in inches, are shown below. Each surface

should have a .2" thickness. The holes' axes must intersect the line that

connects the midpoints of one end of the beam web to the other. The holes

are equally spaced along this line.

Define loads and boundary conditions. The left (or larger) end of the spar

should be immovable. The part is loaded on the top surface(s) with a total

load of (100, -200, 0) in x, y, and z directions, respectively. Run a static

analysis, using convergence of .05%.

Place design parameters on the three holes, allowing them to vary in

radius from .25” to .4”. Using the existing static analysis, run sensitivity

studies and/or an optimization to minimize mass while keeping the

maximum Von Mises stress below 1900 psi and the maximum

displacement magnitude below .0025 inches.

Figure 1: Wing Spar



NOTES

Designing a Valve Housing

ABC Valve Company has an existing line of valves that have been in

production for over 35 years. They have an excellent safety record with

these valves. Lately, ABC Valve Co. has been losing some existing

accounts due to cost. ABC refuses to skimp on quality and safety, but

must find a way to reduce cost. ABC makes over one million valves a

year, and the ability to reduce material costs was judged to be imperative.

As a new engineer with the company, you were sent to Pro/MECHANICA

training. You were asked to evaluate the existing line of valves. After

evaluating each valve you were asked to propose improvements that

would reduce cost, increase valve life, and maintain the current safety

record.

The first part you are to evaluate is a small brass valve that is shown in the

following figure. This valve must be manufactured out of brass, due to the

environment to which it is exposed.

• Naval Brass Material Properties:

• Specific Weight = 0.304 lb/in3

• Modulus of Elasticity = 15,000 ksi

• Poisson's Ratio = 0.35

• Yield Stress = 60 ksi

• Ultimate Stress = 85 ksi

This design meets all OSHA's safety requirements. OSHA allows for

pressure valves to yield at 1.5 times their designed operating pressure.

This little valve is designed to a maximum operating pressure of 600 psi.

Under pressure testing the valve began to yield between 900 - 1,000 psi,

thus meeting the limits. Your assignment is to:

• Build this valve and confirm these test results.

• Propose changes that would reduce material costs while keeping thefailure pressure the same or higher.

There are certain design constraints that your final design must not violate.

You may not reduce the volume that is free inside the valve. For example,

the inside height must remain 0.875 inches, and the ID must remain 1.812

inches. The inside corner radii's can be as large as 0.075 inches. The 0.275

inch base must remain this thick, and top thread length must not change.

The overall height can not change either, due to current design constraints.



NOTES

The top outside thread is capped with a plastic cap to allow the housing to

hold pressure. This adds essentially no structural strength, so it need not be

modeled.

The bottom inside thread is where the pressure feed is attached, and

should be fixed from translating in all three directions.

A uniform pressure should be applied to all inside areas.

Use Failure due to yielding as your failure criteria on this valve. This is

Max. Distortion Energy Theory (or Von Mises - Henckly Theory). Max

distortion energy theory has been found to agree best with available test

data for ductile materials.

Figure 2: Valve Housing



NOTES

Designing a Heat Sink

You must attach a heat sink to a 20W CPU that has been running too hot

in past designs. This CPU will be mounted to a circuit card assembly for a

flight control computer box in an aircraft. An engineer looks in a vendor

catalog to find a simple “heat sink” that will fit the profile of the CPU. He

discovers that there are 40 different types to choose from that also vary in

price and availability. There is no forced air moving over this heat sink.

The challenge is to select the best heat sink for the job.

The engineer must use Pro/MECHANICA to validate a base line heat sink,

then use sensitivities and optimization to decrease the mass of the part

while maintaining a maximum temperature of 135 degrees F. These

studies will assist the engineer in selecting the proper heat sink for the

application at hand. The initial model will have a 20W heat source placed

on the bottom surface, and a convection of 0.01 placed on the long vertical

faces of the fins.

hstart = 0.01 (lbf /in degree F sec) => free convection or no forced air.

Q = 20 (Watts) = 14.75 (lbf in/sec).

Figure 3: Heat Sink Drawing



NOTES

Analyzing a Buckling Ring

Determine the best way to simplify the buckling analysis of a disk under

radial compression.

You are designing components for a jet engine. One of your components

is a complex ring that undergoes a radial (inward) load. You wish to see if

that load is at or above the critical load that will induce linear buckling.

The complex model would take a long time to run, so you would like to

simplify the model, using shells, symmetry, and/or axisymmetric

modeling. Not knowing your buckling mode shapes ahead of time,

however, you're not sure what kinds of simplifications are appropriate. So

you should build a full 3D solid test model with the approximate shape of

your ring, look at the mode shapes, estimate what types of simplification

that you can put on the model, build a simplified test model, and then run

that simplified model to confirm validity.

If the simplified test model gives the same answers as the full test model,

then you can be reasonably confident that the complex model can be

simplified in the same way.

The test model with the same approximate shape as your real-world part

would be an annulus with an outer diameter of 2 meters, an inner diameter

of .2 meters, and a thickness of .02 meters, as shown in the following

figure. The material is “Steel”. Remember to add your constraints and

loads in the current working coordinate system. Build your model with

solid elements. Since buckling analyses take more time to run than regular

static analyses, make sure to use whatever element creation method

necessary such that there are fewer than 100 solid elements, or you will

spend too much time waiting for the analysis to solve. Constrain the inner

radius of the annulus in all 6 DOF. Load the outer radius with an inward

radial load. Run a buckling analysis for the first 5 buckling load factors

(BLF), with all convergences set to 10%

Look at animations of the buckling shapes that correspond to each of the

BLF.

Are all five half symmetric? If so, you could cut the model in half, add

appropriate symmetric boundary conditions, and run it that way. Are all

five quarter symmetric? If so, you could cut the model in quarters, again

adding appropriate symmetric boundary conditions. Are all 5

axisymmetric? If so, you could rebuild this model as axisymmetric.



NOTES

Decide how you wish to simplify the model (half symmetric, quarter

symmetric, or axisymmetric). Then rebuild the test model with shell

elements. Run the simplified test model. Notice that the shell model runs

much, much faster than the solid model.

Compare the BLF and buckling shapes in the simplified shell test model to

those from the solid test model. Are they essentially the same? Does your

simplified model capture a wide enough numerical range of BLF that you

are confident that you've captured the major BLF of concern? If the

answer to both of these questions is “yes”, then your simplification of the

solid model is valid in an engineering sense, and you can expect that a

similar simplification of your real world part would be similarly valid.

Based on either of your models, would the part be able to sustain a

500,000 N load without undergoing linear static buckling?

Figure 4: Ring

Analyzing a Beverage Can

You will create a shell model of a beverage can and determine how much

stiffer the can is with positive pressure inside (before being opened) vs.

with atmospheric pressure inside (after being opened).

If you are starting in Pro/ENGINEER, create the can_body and can_lid

parts. Make sure to start each part with a default coordinate system and

default datum planes. Use an aluminum material for the body and a steel

material for the lid. Auto-pair each part and check the results using the

Shell Compress command. Assemble the parts together, making sure youuse offsets (mate or align) appropriate to allow the shell compressions of

the parts to meet up edge to edge. Check the shell compression of the

assembly for connectivity before preceding.



NOTES

If you are starting in Pro/MECHANICA Structure, define the midplane

surfaces for the body and the lid in one part, making sure that associativity

exists around the upper edge.

Apply a breathing constraint on the bottom surface of the can using a

cylindrical coordinate system (i.e. constrain theta and z translations).

There will be two load sets, a pressure load set and a ‘step' load set

(simulating standing on the can):

• Apply a 30 psi pressure load to all the internal surfaces of the can(don't pressurize the rim on top) in a load set called press_load.

Display the load to verify that the pressure is directed outward.

• Apply a -165 lb load in the negative z-direction along a single edge onthe rim of the can (the top surface will be compressed so a load on the

surface will cause an error). Use the load set name step_load. Display

the load to verify its distribution.

Next you will define three analyses. For each analysis, converge to 10%

on Local Displacement, Local Strain Energy and Global RMS Stress.

Allow a maximum p-order of 9 and increase the plotting grid to 7 or more.

The analysis types and load sets are as follows:

• A Static analysis called ‘press_ld_only' will have only the pressureload set applied.

• Another Static analysis will have only the step load applied.

• A Pre-stress Static analysis called ‘pre_sts_step' will have only thestep load applied. Click the Page Down button and verify that the

specified Static Analysis (providing the pre-stress condition) is the ‘

press_ld_only' analysis already defined.

Run the analyses one at a time or together in a design study called

something like ‘can_study'.

Compute the stiffness for the pressurized can and compare to the stiffness

of the ‘open' (de-pressurized) can. Stiffness units are force per length and

the stiffness values can be calculated by dividing the applied load (165

lbs) by the displacement of the top of the can.

If you have extra time you can create a Buckling analysis using the

step_load load set. Find the first two or three Buckling Modes with 10%

convergence on the Buckling Load Factor & Local Displacement & Local

Strain Energy & RMS Stress. Use a maximum p-order of 9 and a plotting

grid of 7 or more.



NOTES

Figure 5: Beverage Can Body

Figure 6: Beverage Can Lid



NOTES

STUDENT PROJECT HINTS

Flagpole

1. Build a shell model. Flag poles are generally thin walled, so a solid

model would contain too many elements.

2. Use extruded or lofted surfaces.

3. Apply all loads, constraints, and properties to geometry (curves

and surfaces) not elements, so that if Pro/MECHANICA must re-

mesh as a result of design variable changes, it can.

4. Put the end load and the gravity load in the same load set, for

easier display of results.

5. Use Total Load Applied at Point to apply the load at the end of the

pole.

6. Use Load > Gravity to apply the 3G load, which has a magnitude

of -29.4 m/s^2 (in MNS units) and -29400 mm/s^2 (in mmNS

units).

7. Converge on the quantity of interest, the maximum von Mises

stress measure.

8. The maximum von Mises stress in the model must be below

(193e6/4=) 4.5e7 Pa (in MNS units) or 45 Mpa (in mmNS units.)

Driveshaft

1. Since drive shafts are generally thick walled structures, you should

use solid elements in your model.

2. Shell mesh a surface and then extrude it. If you AutoGEM the

surface, consider the number of elements created, and whether you

can more efficiently hand-mesh the same surface.

3. Note the aspect ratios of the solids you create. This model has a

very simple and smooth load path, so there's no reason not to use

aspect ratios of 20 or 30 to 1. At the same time, though, design

your mesh so that you can change the geometry of the model with

a minimum of automatic smoothening and regeneration by the

engine.



NOTES

4. You must have some sort of constraint at the loaded end of the

shaft. Consider defining a User Coordinate System before defining

the constraint, so that it's in a system other than the World

Coordinate System.

5. Use Total Load Applied at Point to apply the load at the end of the

pole.

6. After running your first static analysis, look at fringe plots of

maximum Von Mises stress and maximum principal stress. Which

one do you consider to be a better failure criteria?

7. The stress in the model (whichever stress criteria you choose to

use) must be below (193e6/4=) 4.5e7 Pa (in MNS units) or 45 Mpa

(in mmNS units.)

8. The default number of requested modes, 4, will be enough to

confirm that the frequency of the first mode is significantly below

the frequency of the next lowest mode.

1.

Wing Spar

All users:

1. The dimensions shown in the diagram refer to the “ideal” part.

Since a shell model uses midsurfaces, you will need to figure out

your dimensions with reference to the midsurfaces.

2. The performance criteria are maximum Von Mises stress and

maximum displacement magnitude. Specify that the static analyses

converge on these quantities.

3. To be able to specify your convergence percentage, you must run

the Multipass Adaptive Convergence Algorithm.

4. If your top surface is actually two separate surfaces, you will need

to place two loads of (50, -200, 0) on each of those surfaces.

5. Make your optimization convergence 1%, and limit your

maximum number of iterations to 20.

If using Pro/MECHANICA in Integrated Mode:

1. The part geometry and material must be in inches.



NOTES

2. Careful attention must be paid to the thickness of the beam. These

surfaces will be paired at a later time, so this step is very critical.

We want to have a .2” surface thickness property after

compression.

3. Place an “immovable” displacement constraint on the left hand or

thicker end of the part. The constraints must be on the inside edges

of the surface for them to properly pair during the compression.

The constraints must be for all translations but no rotations.

Valve Housing

1. Use symmetric boundary constraints to reduce the size of the

model. A 30, 45, or 90 degree section would run much more

quickly, and with less disk, than the full 360 degree model.

2. The last paragraph in the instructions that refers to Max. Distortion

Energy Theory (or von Mises - Henckly Theory) means that you

should use Maximum Von Mises stress as your failure criteria. It

should never exceed 60 ksi (60e3 psi), and it should be the quantity

upon which your static analysis converges.

If using Pro/MECHANICA in Integrated Mode:

1. Start your model by creating a DATUM COORD SYS, and

DEFAULT DATUM PLANES.

2. Build your profile on the DTM3, the XY plane of the coordinate

system.

3. When defining your revolved protrusion select Variable as the

REV TO option. Enter a value of about 15 to 20 degrees. Use this

parts symmetry to reduce the GEA model size.

4. When defining the fillets and rounds use the SURF-SURF option.

If you use the default EDGE option, the regeneration will fail if

you Redefine the protrusion to 360 degrees. If you use SURF-

SURF then there is no problem with Redefining the protrusion.

5. As the drawing states all of the unmarked radii are 0.032 inches.

These do not have to remain all the same value. Make them

separate rounds, and do not define relationships between them.

6. To make your design parameters easy to remember, you may want

to modify the dimension cosmetics of the dimension symbols, to

more logical names. For example: Rename a radius dimension

from Rd15 to Rtop_rad.



NOTES

If using Pro/MECHANICA in Independent Mode:

1. Build your geometry on the default XY plane, with the Y-axis as

the valves centerline.

2. For the Model Type use 2D Axisymmetric.

3. As the drawing states all of the unmarked radii are 0.032 inches.

These do not have to remain all the same value. Have them defined

by separate Parameters.

Heat Sink

1. Starting in Pro/MECHANICA Structure, create the surface of

extrusion according to the dimensions given above, and AutoGEM

and extrude this surface 1”.

2. Use AL2014_IPS is the material.

3. Place a “Total” heat load of 14.75 on the base surface.

4. Place a convection coefficient of 0.01 lbf /in deg F sec and Bulk

temperature of 90 deg. F, on the long vertical faces of the fins.

There should be a total of 12 surfaces selected.

Validation Analysis:

1. Convergence Method: Multipass Adaptive.

2. Convergence: Measures: Local Temps & Local & Global Energy

Norms 1%.

Design Variables and Sensitivity Studies:

1. For the fin height, translate the top fin surface. Original height =

0.7”. Final height = .2”

2. For the base thickness, translate the base surface. Original

thickness = .3”. Final thickness =.15”

3. All convection Film Coefficients should range from 0.01 to 1. The

quantity 1 is derived from 2 cfm of airflow that could be

potentially rerouted through the enclosure to the CPU. The

question should be asked “What does a varying convection

coefficient relate to physically”. You should be comparing this

variable to mass flow rate.

4. Plot max_temperature vs. design variable.



NOTES

5. Run sensitivities on all the above, referencing the same validation

analysis mentioned before.

Optimization

1. Goal: minimize total_mass.

2. Limits: max_temperature < 135 degree F.

3. Optimization Convergence should be 1%, Maximum # Iterations =

20.

4. Deselect Smooth, Regenerate, & repeat

Extra Credit:

1. Run a sensitivity on the Convection Bulk Temperature from 70 to

130 Deg. F. The question should be asked, “What does a varying

convection bulk temperature relate to physically”. Students should

relate this to the ambient operating temperature of the flight control

computer box in the air craft.

Buckling Ring

1. Since the output of a buckling analysis is a buckling load factorthat represents the critical buckling load over the current load,

enter a magnitude of “1” for the solid model radial load. That way,

the buckling load factor will be equal to the critical buckling load.

If you build quarter or half symmetric models later, make sure to

scale the load so that you are comparing “apples to apples” when

comparing the buckling load factors. If you build an axisymmetric

model, use a value of “1” since axisymmetric loads are input with

the magnitude that they would have on an entire model.

2. Some of your buckling shapes (and BLF) will essentially be

duplicates of each other. This is normal- Mechanica is finding two

different “poles” of the same buckling shape.

3. One criteria for deciding if you've looked at enough BLF might be

the following: if the highest BLF is at least twice the lowest BLF,

then your BLF are not just “clustered” around one particular value,

and it would be very unlikely that a small design change would

make a previously unseen buckling shape (with a higher BLF

value) drop it's BLF in half to become the new, lowest (and hence

most critical) buckling shape.



NOTES

Beverage Can

1. Below are two more efficient ways to analyze the stiffness of the

can (using less elements; therefore, solving more quickly);

however, these simplified models will not be suitable for a

buckling analysis.

2. To save analysis time, you can cut the Pro/ENGINEER assembly

to a smaller section (a 30 degree pie section for instance) and apply

symmetry constraints at the boundaries. A 30 degree section

should require about 1/12 the degrees of freedom to solve than a

360 degree section. Remember to reduce the load appropriately if

using a partial model!

3. Since the model and loads are axisymmetric you could run the

model in independent mode using an axisymmetric model type and

2D-shell elements along the boundary. To do this cut the model to

a section with one side of the cut on the xy plane. Transfer the

model to Independent MEC, verifying that the setting to Use Pairs

is checked. Once in Mechanica do a top view and delete all

geometry except the curves on the xy plane. Make sure all

geometry is in the positive xy plane and use the Axisymmetric

model type. AutoGEM the curves and apply the loads and

constraints.

Note:

If you attempt this Exercise in Independent Mode, use only theouter surfaces of the can -- not the midsurfaces.


Page A-1

Appendix

Using PTC HelpIn this module you learn how to use PTC Help to search for

Pro/ENGINEER information. PTC Help provides quick references

and detailed information on selected topics.

Objectives


• Start PTC Help.

• Search for specific information about Pro/ENGINEER.

• Obtain context-sensitive help while performing a task.


Page A-2 Append ix

NOTES

DEFINING THE PTC HELP FEATURES

The PTC Help system is integrated into Pro/ENGINEER. It offers:

• A table of contents, an index, and searching capability.

• Context-sensitive help access.

• Online tutorials focussed on teaching different aspects of the software.

• Expanded help topics available as special dialog boxes.

For addition help, the PTC Technical Support online Knowledge

Database features thousands of suggested techniques. Detailed

information on the Knowledge Database is referenced in the Technical

Support Appendix.

USING THE Pro/ENGINEER ONLINE HELP

The Pro/ENGINEER Online Help can be accessed:

• Using the Main Menu.

1. Click Help > Contents and Index from the Pro/ENGINEER Main

Menu, as shown in the following figure.

Figure 1: Accessing Help from the Main Menu


Using PTC Help Page A-3

NOTES

The Pro/ENGINEER Online Help homepage displays in your web

browser window. A list of topics displays in the left frame of the window.

Figure 2: Online Help Homepage

• Using Context-Sensitive Help.

1. Click the icon in the Pro/ENGINEER Main Menu toolbar.

2. Click any icon or any part of the Pro/ENGINEER Main Menu for

detailed information on a particular item. A browser window

displays with a description of the item.


Page A-4 Append ix

NOTES

In the following example, clicking the Model Tree icon in the Main Menu

toolbar displays a browser window explaining the Model Tree icon

functionality.

Figure 3: Model Tree Icon

Figure 4: The Help Browser Window for the Model Tree Icon

3. The lower left corner of the browser window displays a See Also

link, as shown in the previous figure



NOTES

4. The See Also link provides a list of related topics, as shown in the

following figure.

Figure 5: The See Also List of Topics


Page A-6 Append ix

NOTES

• Using the Pro/ENGINEER Menu Manager.

1. Click the icon in the Pro/ENGINEER Main Menu toolbar.

2. Select any menu command from the Menu Manager.

3. A TOPIC ROUTER browser window opens with a list of topic links

that explain the menu command.

4. Select a topic link.

The X-Section menu command in the Menu Manager displays the TOPIC

ROUTER browser window with a list of two related topics, as shown in the

following figure.

Figure 6: Using the Menu Manager



NOTES

• Using Vertical Menu Commands.

1. Right-click and hold on a menu command until the GETHELP

window displays.

Figure 7: Right-Clicking in Menu Manager


Page A-8 Append ix

NOTES

Defining the PTC Help Table of Contents

There are four branches in the PTC Help Table of Contents:

Figure 8: Four Main Branches in Help System

Figure 9: Foundation and Additional Modules in Help


Page B-1

Appendix

Technical Support

In this module you learn about the telephone hotline and the online

services that provide 24 hour / 7 day Technical Support.

Objectives

After completing this module you will be able to:

• Open a Technical Support telephone call.

• Register for online Technical Support.

• Navigate the PTC Products Knowledge Base.

• Locate telephone numbers for technical support and services.


Page B-2 Append ix B

NOTES

Locating the Technical Support Web Page

Select SUPPORT from the PTC HOME PAGE, www.ptc.com, or go

directly to www.ptc.com/support/support.htm.

Opening Technical Support Calls via E-Mail

Send email to [email protected]. Use copen as the e-mail subject.

Use the following format (or download the template from

www.ptc.com/cs/doc/copen.htm):

FNAME First Name

LNAME Last Name

CALLCENTER U.S., Germany, France, U.K.,

Singapore,Tokyo

TELEPHONE NNN NNN-NNNN x-NNNN

CONFIG_ID NNNNNN

PRODUCT

MODULE

PRIORITY

DESC_BEGIN description starts

description continues

description ends

DESC_END


Custom er Support In fo rmat ion Page B-3

NOTES

Opening Technical Support Calls via Telephone

For your local Technical Support Center, refer to the Contact Information

telephone list referenced at the end of this module.

When logging a call, you must provide the following information to the

Technical Support Engineer:

• Your PTC softwareConfiguration ID.

• Your name andtelephone number.

• The PTC product name.

• Priority of the issue.

Opening Technical Support Calls via the Web

To open Technical Support calls 24 / 7, select PRO/CALL LOGGERY in the

PTC web site, www.ptc.com/support.

Sending Data Files to PTC Technical Support

To send data files to PTC Technical Support, follow the instructions at:

www.ptc.com/support/cs_guide/additional.htm.

Note:

When a call is resolved, your data is deleted by a Technical

Support Engineer. Your data confidential and will not be shared

with any third party vendors, under any circumstances. You may

request a Non-Disclosure Agreement from the Technical SupportEn gineer.



NOTES

Routing Your Technical Support Calls

Call

Customer question

Telephone Call Web Call

Tech SupportEngineer

creates a call in the database

Call is automatically created

in the database

Investigation Call Back and Investigation

Support Engineer

solves issue or

reports it

to Development (SPR)

SPRSoftware Performance Report

Software Performance Report (SPR)

SPR Verification through Tech. Support Engineer

Update CD to customer

SPR fixed from Development



NOTES

Technical Support Call Priorities

• Extremely Critical – Work stopped

• Critical – Work severely impacted

• Urgent – Work impacted

• Non Critical

• General Information

Software Performance Report Priorities

• Top Priority – Highly critical software issue that is causing a workstoppage.

• High – Critical software issue that affects immediate work and apractical alternative technique is not available.

• Medium – Software issue that does not affect immediate work or apractical alternative technique is available.

Registering for On-Line Support

To open a registration form, go to www.ptc.com/support,

click Sign-up Online, then enter your CONFIGURATION ID.

To find your CONFIGURATION ID, click Help > About Pro/ENGINEER.

Complete the information needed to identify yourself as a user. Note your

username and password for future reference.



NOTES

Using the Online Services

After you have registered, you will have full access to the online tools.



NOTES

Finding Answers in the Knowledge Base

The Technical Support KNOWLEDGE BASE contains over 18,000

documents.

Technical Application Notes (TANs), Technical Point of Interest (TPIs),

Frequently Asked Questions (FAQs), and Suggested Techniques offer up-to-

date information about all relevant software areas.



NOTES

Terminology Used by Technical Support

TAN – A Technical Application Note provides information about SPRs that

may affect more than just the customer originally reporting an issue. TANs

also may provide alternative techniques to allow a user to continue working.

TPI – A Technical Point of Interest provides additional technical

information about a software product. TPIs are created by Technical Support

to document the resolution of common issues reported in actual customer

calls. TPIs are similar to TANs, but do not reference an SPR.

Suggested Techniques – Provides step-by-step instructions including

screen snapshots, on how to use PTC software to complete common tasks.

FAQ – Frequently Asked Questions provides answers to many of the most

commonly asked questions compiled from the PTC Technical Support

database.

FAQs and Suggested Techniques are available in English, French, and

German.

Getting Up-To-Date Information

To subscribe to our KNOWLEDGE BASE MONITOR e-mail service, go to

www.ptc.com/support, and click Technical Support > Online Support

Applications > Knowledge Base Monitor. You will receive daily e-mail

with the latest information on your product.

Figure 1: Knowledge Base Monitor Sign Up



NOTES

CONTACT INFORMATION

Technical Support Worldwide Electronic Services

The following services are available 24 / 7:

• Web

� www.ptc.com/support/index.htm (Support)

� www.ptc.com/company/contacts/edserv.htm (Education)

• E-mail

� [email protected] (for opening calls and sending data)

� [email protected]

(for suggestions about the Customer Service web site)

• FTP

• ftp.ptc.com (for transferring files to PTC Technical Support)

Technical Support Customer Feedback Line

The Customer Feedback Line is intended for general customer service

concerns that are not technical product issues.

• E-mail

� [email protected]

• Telephone

� www.ptc.com/cs/doc/feedback_nums.htm



NOTES

TELEPHONE AND FAX INFORMATION

For assistance with technical issues, contact the Electronic Services noted in

the previous section, or the Technical Support line as listed in the Telephone

and Fax Information sections below.

PTC has nine integrated Technical Support Call Centers in North America,

Europe, and Asia. Our worldwide coverage ensures telephone access to

Technical Support for customers in all time zones and in local languages.

North America Telephone Information

Customer Services (including Technical Support, License Management, and

Documentation Requests):

• Within the United States and Canada

� 800-477-6435

• Outside the United States and Canada:

� 781-370-5332

� 781-370-5513

• Maintenance

� 888-782-3774

• Education

� 888-782-3773



NOTES

Europe Telephone Information

Technical Support Telephone Numbers

• Austria

� 0800 29 7542

• Belgium

� 0800-15-241 (French)

� 0800-72567 (Dutch)

• Denmark

� 08001-5593

• Finland

� 0800-117092

• France

� 0800-14-19-52

• Germany

� 0180-2245132

� 49-89-32106-111 (for Pro/MECHANICA® outside of

Germany)

• Ireland

� 1-800-409-1622

• Israel

� 1-800-945-42-95 (All languages including Hebrew)

� 77-150-21-34 (English only)

• Italy

� 0800-79-05-33

• Luxembourg

� 0800-23-50



NOTES

• Netherlands

� 0800022-4519

• Norway

� 8001-1872

• Portugal

� 05-05-33-73-69

• South Africa

� 0800-991068

• Spain

� 900-95-33-39

• Sweden

� 020-791484

• Switzerland

� 0800-55-38-33 (French)

� 0800-83-75-58 (Italian)

� 0800-552428 (German)

• United Kingdom

� 0800-318677

License Management Telephone Numbers

• Belgium

� 0800-75376

• Denmark

� 8001-5593

• Finland

� 0800-117-092

• Eastern Europe

� 44 1252 817 078

• France

� 0800-14-19-52

• Germany

� 49 (0) 89-32106-0



NOTES

• Ireland

� 1-800-409-1622

• Italy

� 39 (0) 39-65651

• Netherlands

� 0800-022-0543

• Norway

� 8001-1872

• Portugal

� 05-05-33-73-69

• Russia

� 44 1252 817 078

• Spain

� 900-95-33-39

• Sweden

� 020-791484

• Switzerland

� 41 (0) 1-8-24-34-44

• United Kingdom

� 0800-31-8677



NOTES

Education Services Telephone Numbers

• Benelux

� 31-73-644-2705

• France

� 33-1-69-33-65-50

• Germany

� 49 (0) 89-32106-325

• Italy

� 39-039-65-65-652

� 39-039-6565-1

• Spain/Portugal

� 34-91-452-01-00

• Sweden

� 46-8-590-956-00 (Malmo)

� 46-8-590-956-46 (Upplands Vasby)

• Switzerland

� 41 (0) 1-820-00-80

• United Kingdom

� 44-0800-212-565 (toll free within UK)

� 44-1252-817-140



NOTES

Asia and Pacific Rim Telephone Information

Technical Support Telephone Numbers

• Australia

� 1800-553-565

• China*

� 10800-650-8185 (international toll free)

� 108-657 (manual toll free)

• Hong Kong

� 800-933309

• India*

� 000-6517

• Indonesia

� 001-803-65-7250

� 7-2-48-55-00-35

• Japan

� 120-20-9023

• Malaysia

� 1-800-80-1026

• New Zealand

� 0800-44-4376

• Philippines

� 1800-1-651-0176

• Singapore

� 65-830-9899

• South Korea

� 00798-65-1-7078 (international toll free)

� 080-3469-001 (domestic toll free)



NOTES

• Taiwan

� 0080-65-1256 (international toll free)

� 080-013069 (domestic toll free)

• Thailand

� 001-800-65-6213

Callers dialing from India or China must provide the operator with the

respective string:

• China

� MTF8309729

• India

� MTF8309752

The operator will then connect you to the Singapore Technical Support

Center.

License Management Telephone Numbers

• Japan

� 81 (0) 3-3346-8280

• Hong Kong

� (852) 2802-8982

Education Services Telephone Numbers

• Australia

� 61 2 9955 2833 (Sydney)

� 61 3 9561 4111 (Melbourne)

• China

� 86-20-87554426 (GuangZhou)

� 86-21-62785080 (Shanghai)

� 86-10-65908699 (Beijing)

• Hong Kong

� 852-28028982

• India



NOTES

� 91-80-2267272 Ext.#306 (Bangalore)

� 91-11-6474701 (New Delhi)

� 91-226513152 (Mumbai)

• Japan

� 81-3-3346-8268

• Malaysia

� 03-754 8198



NOTES

• Singapore

� 65-8309866

• South Korea

� 82-2-3469-1080

• Taiwan

� 886-2-758-8600 (Taipei)

� 886-4-3103311 (Taichung)

� 886-7-3323211 (Kaohsiung)

ELECTRONIC SERVICES

Up-to-Date

Information+ Worldwide

ISO 9000

Certification

Quality Control

System

= Maximum

Productivity

with

PTC

Products


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