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Course in ANSYS

Example0100

Example0100 2

Example Cantilever beam

E = 210000N/mm2

n = 0.3L = 100mm

a = 10mm

b = 10mm

F = 100N

Objective:Compute the maximum deflectionTasks:Create a table and compare resultswith results obtained from beam theory?Display the deflection figure?Topics:Topics: Start of analysis, Element type,Real constants, Material, modeling, ele-ment size for beam models, saving/restoring

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Example0100 3

Modeling considerations As you begin your model generation, you will (consciously or

unconsciously) make a number of decisions that determine how youwill mathematically simulate the physical system: What are the objectives of your analysis? Will you model all, or just a portion, of the physical system? How much detail will you include in your model? What kinds of elements will you use? How dense should your finite

element mesh be?

In general, you will attempt to balance computational expense (CPUtime, etc.) against precision of results as you answer thesequestions.

The decisions you make in the planning stage of your analysis will

largely govern the success or failure of your analysis efforts.

Example0100 4

Modeling considerations

Linear or Higher Order Elements Take Advantage of Symmetry

The axis of symmetry mustcoincide with the global Cartesian Y-axis. Negative nodal X-coordinates are not permitted. The global Cartesian Y-direction represents the axial direction, the

global Cartesian X-direction represents the radial direction, and theglobal Cartesian Z-direction corresponds to the circumferential direction. Your model should be assembled using appropriate element types:

For axisymmetric models, use applicable 2-D solids with KEYOPT(3) = 1,and/or axisymmetric shells. In addition, various link, contact, combination,and surface elements can be included in a model that also containsaxisymmetric solids or shells. (The program will not realize that these "other"elements are axisymmetric unless axisymmetric solids or shells are present.)

How Much Detail to Include Appropriate Mesh Density

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Example - title

Utility Menu > File > Change Title/title, Cantilever beam

Utility Menu > File > Change Jobname/jobname, Example0100

Enter: Cantilever beam

Command line entryGUI

Enter: Example0100

Example0100 6

Example - KeypointsPreprocessor > Modeling > Create > Keypoints > In Active CS/PREP7K,,,,K,,100,,

100

Press Apply

Note: An empty boxresult in a zero. It isallowed to enter 0.0in each box.

Enter 100 andPress Apply

General format:K,#,X,Y,Z

# Keypoint numberX Keypoint x-coordinateY Keypoint y-coordinateZ Keypoint z-coordinate

Note: An empty #result in automaticnumbering.

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Example - NumberingUtility Menu > PlotCtrls > Numbering Switch on Keypoint numbers

Press OK

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Example - LinesPreprocessor > Modeling > Create > Lines > Lines > Straight LineCreate a line between Keypoint 1 and Keypoint 2.L,1,2

HINT: By clicking with the right-hand mouse button you shiftbetween the Pick/Unpick

function. This is indicated bythe direction of the cursorarrow:

Pick: upward arrow

Unpick: downward arrow

Press OK or Cancelto finish selection

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Example - Plot - Nodes

Plot Keypoints and Lines

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Example Element TypePreprocessor > Element Type > Add/Edit/Delete

Press Add

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Example - Element TypePreprocessor > Element Type > Add/Edit/Delete

Press Options

Press Help to learn more about theelement.

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Example Real ConstantsPreprocessor > Real Constants > Add

Place the cursoron the relevantelement andpress OK

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Example - Real ConstantsPreprocessor > Real Constants > Add

Press OK

Press Closeto finish

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Example - Material PropertiesPreprocessor > Material Props > Material Models

Double Clickto step in thematerial tree

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Example - Material PropertiesPreprocessor > Material Props > Material ModelsEnter:Modulus of elasticity

Enter:Poissons ratio

Click hereto Close

Press OK

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Example - MeshingPreprocessor > Meshing > Size Cntrls > ManualSize > Lines > Picked Lines

Select/PickLines to

specifymesh sizefor

Press OK when finish with selection Enter 1

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Example - MeshingPreprocessor > Meshing > Mesh > Lines

Select individual lines to be meshed by Picking

Select all lines defined to be meshed

NB: It is often necessary to Clear the model for

example if Element Type is to be changed

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Example Analysis Type

Solution > Analysis Type > New Analysis

File > Write DB log file

Enter example0100.lgw

Press OK

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Example Define LoadsSolution > Define Loads > Apply > Structural > Displacement > On KeypointsSelect keypoint 1

Press OK

Select All DOF to fix/clamp the beam

Example0100 20

Example Define LoadsSolution > Define Loads > Apply > Structural > Force/Moment > On Keypoints

Change to FY

Select keypoint 2

Enter -100Press OK to finish

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Example - SaveDisplay of Analysis model

Save the model

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Example - SolveSolution > Solve > Current LS

Press OK

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Example - SolvePress ClosePress hereto Close

Example0100 24

Example - PostProcessingGeneral Postproc > Plot Results > Deformed Shape

Select Def+undeformedand Press OK

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Example - PostProcessing

Read Maximum displacement: DMX

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Example Comments/Questions

Why is it relevant to consider a Beammodel in many cases?

The example0100.lgw can be edited inNotepad

What are the assumptions in beamtheory?

Will the number of elements affect thesolution?

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File menu

Clears (zeros out) the database stored inmemory. Clearing the database has the sameeffect as leaving and reentering the ANSYSprogram, but does not require you to exit.

You can include commands to beexecuted when the program starts up inthe start71.ans file.