multibody dynamics a, wb1310 1 introduction to adams course manual for multibody dynamics a, wb1310...

1Multibody Dynamics A, wb1310

Introduction to ADAMSIntroduction to ADAMSCourse manual for Multibody Dynamics A, wb1310

Martijn Wisse

29th december 1999

revised for V2005.0.0 by Bram Soethoudt

May 2005


Contents

Contents

1Example3

2Program Overview15

3Layout & View Control19

4Parts & Geometry23

5Joints & Motion generators26

6Markers30

7 Springs & Force generators 31

8 Simulations & Animations 35

9 Plotting & Measures 41

10 Tips & Useful Tools 45


Creating a new model

• Start ADAMS-View: Data Analysis & Simulation Software Adams 12.0 Aview ADAMS-View

• Use the startup dialogbox or from the Menu-bar select Build Model New…

• Change the Model Name to ‘example_1’

• Click OK, ADAMS is now ready to construct a model

Example


Environment Settings

To set gravity and units settings:

• From the Menu-bar select Settings Gravity…

• In the Gravity Settings window check the Gravity checkbox

• Apply

• From the Menu-bar select Settings Units…

• Select

Example


Creating a new link

• In the Main Toolbox click the icon Rigid Body: Link

• Check options Length, Width and Depth,

• Fill in desired dimensions: ‘(373mm)’, ‘(6mm)’ and ‘(6mm)’

* Hit return after entering the dimensions

* Notice instructions in lower left corner of screen

• Pick location of first end of link

• Pick second location to define orientation of link

Example


Creating a new joint

• In the Main Toolbox click the icon Joint: Revolute

• Select construction options:

- 1 Location

- Normal to grid

• Pick the location of the revolute joint on an existing rigid body

Example


Naming the model elements

• Right click on the created link

• Select Part: Part_1 Rename

• Change name into ‘.example_1.pendulum’

• Repeat procedure for the created joint

• Rename joint as ‘.example_1.hinge’

Example


Naming the view window

• From the Menu-bar select View View Accessories...

• In the View Accessories window type your id

• Click Enter

• Close View Accessories window

• Your id appears in the upper left corner of the model view window

Example


Rotating model elements

• In the Main Toolbox select the Select-tool

• Left click on the pendulum to select

• In the Main Toolbox select the Center-tool

• Center the view at the hinge

• In the Main Toolbox select the Position-tool

• Rotate the pendulum 30 degrees

Example


Saving the model

• From the Menu-bar select File Export

• In the File Export window right click at File Name

• Select Browse...

• Save model as ‘example_1.cmd’ in the File Selection window

• In the File Export window click OK

• Save your work frequently

Example


Loading a model

• From the Menu-bar select File Import

• In the File Import window right click at File To Read

• Select Browse...

• Open existing ‘.cmd’ - file

* Note: if the model was already loaded, a number of errors appears

Example


Running a simulation

• In the Main Toolbox select the Simulation-tool

• Change the number of steps into ‘100’

• Left click the Start or continue simulation button

• To simulate again, first press the Reset to input configuration button

* Note: The viewport shows the simulation; to return to the model view, left click the Select-tool

* Note: The simulated motion is stored, and available for animation or plotting

Example


Plotting simulation results

• In the Main Toolbox select the Plotting-tool

• For the Object to plot choose Constraint hinge Ax_Ay_Az_Projection_Angles Z

• Click Add Curve

• Double-click Page_1 and click on Plot_1

• Add Title and insert your id as Subtitle

• Click OK

Example


Simulation results

• Print your graph

• To leave the Plot Window click Return to modeling environment

This is the end of the example

Example


The ADAMS interface consists of two main windows:

- the View Window, displaying your current model

- the Main Toolbox

Most common ADAMS functions can be accessed through the Main Toolbox. All functions can also be found under the the Menu bar in the View Window.

The ADAMS interface

Program Overview

Coordinates WindowInstruction BarTriad

Title

Working Grid

Menu BarMain Toolbox

Modeling and simulation tools

Right click to open individual

tool stacks

ContainerDisplay changes depending upon the tool selected from the tools

above


ADAMS has an extensive online help facility in HTML and PDF format.

Most documentation on model construction is to be found under ADAMS/View.

ADAMS Online Help

Program Overview


The ADAMS model hierarchy

Program Overview

Database

Model Plot GUI

Measure Constraint ForceAnalysis

Model ElementsSimulation Output

Results Set

Component

Do not get saved in model command file format (.cmd)(See next Page for explanation)

Curve

More...

Part

Marker Construction points Geometry

The model element naming is consistent with the hierarchy (e.g. model_name.part_name.geometry_name or model_name.joint_name)


1 ADAMS/View Database files (.bin) Include the entire modeling session including models,

simulation results, plots, etc. Are large binary files

2 ADAMS/View Command files (.cmd) Includes only the model elements and their

attributes Are relatively small, editable text files

File Handling in ADAMS

The two most common formats in which models in ADAMS can be saved are:

The other formats in which data in ADAMS can be imported and exported are:

ADAMS/Solver Input files (.adm) Geometry files (STEP, IGES, DXF, DWG,

Wavefront, stereolithography) Test and Spreadsheet data files Simulation results files (.msg, .req, .out, .gra, .res)

Program Overview


View settings

View settings from the Main Toolbox:

Background Color

Triad visibility (the global coordinate system displayed in the lower left corner of the View Window)

View layout

Icon appearance: double click on the Icons button

Setting the View Title:

• From the Menu-bar choose View View Accessories

• Set your id as View Title in the View Accessories window

Layout & View Control


Viewpoint controls

The Viewpoint can be controlled from the Main Toolbox. Click the Select-tool and use the following view controls:

Fit Rotate

Window zoom Pan

Center Zoom

And the preset view orientations:

Front

Right

Top

Isometric



Setting Object Appearances

The appearance of a displayed object can be altered when the object is selected (highlighted):

• color: From the Menu-bar select Edit Appearancechange Color by right-clicking the Color-field

render mode: From the Menu-bar select View Render Mode toggle render on/off in the Main Toolbox



The Working Grid

The Working Grid is used:• as a plane for creating objects• to draw, move, resize, reshape geometry by snapping to grid

Change Working Grid settings by double-clicking the Grid-buttonon the Main Toolbox (first apply the Select-tool)

When creating a new model element, first set the Working Grid with the correct location and orientation.

Set the location of the Grid origin by:• global origin, or• pick location

Set the orientation as one of the principal planes:• Global XY,• Global YZ, or• Global XZ



Creating Parts & Geometry

Each rigid body in ADAMS is modeled as a part. Each part has one or more geometries. To create a new part, start with a geometry, e.g. a box or a cylinder.

To create a new geometry:

• In the Main Toolbox right-click on Rigid Body

• Select the appropriate geometry:

Link Sphere

Box Torus

Cylinder

• Choose New Part or Add To Part

• Enter required dimensions

• Follow instructions in lower left corner of screen

* When adding a geometry to an existing part, check the position of the automatically generated ‘Center of Mass’-marker

Parts & Geometry


Positioning Objects

Reposition objects relative to viewing coordinates

Translate from an initial location to another

Reposition objects relative to the working grid

Rotate about or align with grid or features Position objects by

aligning faces

Translation:Rotation:

Parts & Geometry


Modifying Part Properties

Parts & Geometry

To modify Mass and Inertia properties of a part:

• Right-click on the part to be modified

• ADAMS/View displays the names of all model elements near the cursor

• Select the part to be modified and then select Modify

• In the Modify Rigid Body window enter the user specified mass and inertia values

To modify the name of the part:

• Select the part to be modified and then select Rename


Joints

In ADAMS joints are used to connect rigid bodies to each other or to the ground with a limited number of degrees of freedom.

To create a new joint:

• Both parts to be connected by the joint should already exist

• In the Main Toolbox right-click on Joint

• Choose the appropriate joint:

revolute

translational

• Choose a connection between one part and the ground: 1 location, or between two parts: 2 Bod - 1 loc

• Choose the orientation of the joint by setting the axis for the degree of freedom:

- normal to the Working Grid- in a direction indicated with the mouse


Joints & Motion Generators


A degree of freedom in a joint can be replaced by a prescribed motion. A motion can be defined as displacement, velocity or acceleration as a function of time.

To create a motion generator:

• A joint should already exist

• In the Main Toolbox right-click on Rotational Joint Motion

• Choose the type of motion, equal to the degree of freedom allowed by the joint:

rotational, or

translational

• Enter the desired constant velocity

* When applying a rotational velocity, enter the letter d to ensure that ADAMS uses as units degrees/second


• If an other motion function than a constant speed is desired, modify the motion generator afterwards

Creating a Motion Generator



The prescribed motion of a motion generator can be a complex function of time. First, a motion generator with constant velocity must have been created.

To modify the motion function:

• Select the motion generator and then select Modify

• In the Impose Joint Motion window select the type of motion generator

• Right-click in the ‘F(time)=’-field

• Select Function Builder…

• Define a runtime function, using ‘time’ as independent variable, or

• Enter a more complex predefined function (next page)

Motion Generators with non-constant velocity



To enter a complex mathematical function of time for the motion generator:

• In the Function Builder window select the desired math function

• Use the Assist… dialog box

• Use the Verify button before closing the Function Builder

The Function Builder


* Note: The Function Builder cannot read lines over 80 characters long

* Note: If the function is new to you, see the description in the Help


Markers

In ADAMS, important geometrical points on a rigid body are represented by Markers. A marker is a massless entity, only possessing a location and an orientation. When a new rigid body or joint is created, ADAMS automatically creates the necessary markers (e.g. the ‘Center of Mass’-marker).

When a spring or other force must be attached at a previously undefined location on a part, first a new marker must be created.

To create a new marker:

• In the Main Toolbox right-click on Rigid Body

• Select Marker

• Choose Add to Ground or Add to Part

• For the orientation of the marker, choose one of the principal planes:

- Global XY

- Global YZ

- Global XZ


Markers


Spring/Damper

To create a spring/damper combination:

• Two markers on different parts should already exist for spring attachment

• In the Main Toolbox choose Connector: Translational Spring-Damper

• Check applicable properties and enter user-specified values


To change properties and graphic representation:

• Select spring to be modified and then select Modify

* Note: in order to see the diameter ratio option, load the <Sayfield> menu from the menu bar

Springs & Force Generators


Applied Force: TorqueTo create an applied torque on a rigid body:

• A marker should already exist as point of application for the torque

• In the Main Toolbox right click on Connector

• Select Applied Force:Torque (single component)

• Choose a Runtime Direction and Construction (initial direction)

• Choose Characteristic: - a simple force, or

- a to be defined complex custom function


To alter the force function:

• Right-click on the torque and select Modify

• In the Modify a Torque window right click in the ‘F(time,…)’-field

• Use the Function Builder

* Note: In contrast with a motion generator, an applied torque can be a function of positions of objects



Special Force: Tire

To create a new tire:

• In the Main Toolbox right click on Connector and select Tire

• In the Create Wheel and Tire window enter the following data:

• Enter Name

• Enter user specified Mass and Inertia properties

• Enter the required Tire Property File

• Enter the required Road name (create if it does not exist)

• Enter Location of the cm and Orientation of the wheel axis: default (0,0,0) is the wheel axis along the z-axis


A tire is represented in ADAMS as a special type of force. This special force automagically generates a part for the wheel.


Creating a Road

To create a new road:

• In the Create Wheel and Tire window right click on Road and select Create

• In the Create Road window enter the following data:

• Name

• Part that the road is attached to (usually ground)

• the required road Property File

• adjust the Euler Angles to (0,-90,0) for the plane y=0, contact if y<0


A tire in ADAMS needs a road. Multiple tires can use one road.


Debugging

Before running a simulation, you should check your model; are all parts connected as intended?

To check the number of Degrees of Freedom:

• use the Verify tool in the lower right corner of the screen

• the Information window displays the number of degrees of freedom, the number of moving parts and the number of joints

Simulation & Animation


Running a simulation


To run a simulation:

• In the Main Toolbox select the Simulation-tool

• Select Default analysis

• Enter the desired End Time or Duration

• Enter the desired integration Step Size or Number of Steps

• Select the Debug option, ADAMS shows the Maximum Equation Error window

• Use the Start, Stop and Rewind buttons

• To access advanced simulation settings, apply … (More)

See (next page)


Simulation Settings


Advanced Simulation Settings:

• In the Main Toolbox select the Simulation-tool, then select …(More)

• To find static equilibrium, apply

• To perform a linear modes analysis, first find static equilibrium, then apply, In the Linear Modes Controls window use , and to display and animate the eigenfrequencies and eigenmodes

• To change the integration accuracy, apply Simulation Settings…


Static*Static*LinearLinear

Kinematic*Kinematic* Dynamic*Dynamic*

Linear

Assembly Operation

AssembleAssemble

Eigensolution or State Matrices

Non-Linear

*Automatically performs an assembly operation

Non-Linear

DOF=0 DOF>0

Motion Study Equilibrium Calculation(s)

Types of Virtual Simulations in ADAMS

Default*Default*



Basic Animation Control

After Performing a simulation, the Animation Container on the Main Toolbox can be used to control the animation

Play-forwardPlay-forward

Play-reversePlay-reverse

Stop AnimationStop Animation

Reset to Frame 1Reset to Frame 1Step ForwardStep Forward

Step BackwardStep Backward

Frame SliderFrame SliderModify Animation ViewModify Animation View

Fixed Base: camera is fixed on the ground

Base Part: camera is fixed on the CM of the part

Base Point: camera is fixed on the selected CSMLoop FunctionLoop Function

Drag until the required frame is reached

Select to replay animation indefinitely Advanced Animation featuresAdvanced Animation features



Animation and Rendering

ADAMS has a built-in movie generator, which produces computer animations in .AVI-format.

To make an .AVI-movie:

• After running a simulation, select View Load Animation from the Plotting Main Menu

• Select desired view with the View Control toolbars or right click in main window

• If desired adjust settings for Animation, View, Camera, Record, Overlay, Contours

• Press record and press play to start the recording

• Movie is saved in working directory (default is L:\)



Overview of the Plot

Plotting & Measures

Plotting main menu

Plot locationPlot formatting

Plotting toolbar Return to modelingManage pages of plots


Overview of the Plot Builder

Displays list of current

simulationsDetailed List of Output

Types of results to be displayed:

Objects, Measures, Requests and Results

Manages curves of plots

Plotting & Measures

Parameter to plot against


Useful Plot functions

Useful functions in the Plot Window:

Display Plot Statistics

Zoom

Return to modeling environment

Useful functions in the Plot Builder:

Surf; automatically clears and updates plots as items are selected

Data filter

Plotting & Measures


Creating Measures in ADAMS

To create measures…

1 Use the Main MenuBuild| Measurecan be used for all measures

2 Use the Measure Tool Stack on the Main Toolbox

can be used for point-to-point and included angle measures

3 Use the right mouse button and select Measure from the pop-up menu

can be used for object and point measures

Plotting & Measures


Tips & Tricks

Some general tips & tricks:

• Use the Escape key to abort a command.

• Press ‘Enter’ after input to make sure that the new value is set.

• Edit Copy generates a copy at the same location as the original. Right-click on the model to select the copied element.

• Right click on any field for suggestions or options.

Tips & Useful Tools


Navigating through a Modeling Database

Use the Database Navigator to view and select objects in a modeling databaseTo open the Database navigator…

Use the menu barTools| Database Navigator

Execute an editing command when no object is selected

The Database Navigator only displays those types of objects that are appropriate for the command

you are executing

“+” indicates existence of hidden children

“-” indicates all children objects are displayed

Tips & Useful Tools


Using the Command Navigator

Use the command Navigator to enter ADAMS/View commands without knowing the entire command syntaxThe Command Navigator…

displays a list of all the ADAMS/View command keywords

corresponds to the matching menus available in previous versions of ADAMS/View

lets users perform advanced commands not immediately accessible

helps users learn the command syntax when customizing ADAMS/View

“+” indicates existence of hidden command levels

“-” indicates that the next command level is currently displayed

No indicator- when selected, a dialog box appears in which you enter values to execute the command

Tips & Useful Tools


Using the Information Window

The Information window displays different types of information about a model

Display parent and child information

Display object information

Display an object’s modify dialog box

Clear information window

Save information to a text file

Set the information mode

Display a text file

Copy text

Tips & Useful Tools


Using the Select List Manager

The Select List manager is used to…

get a list of selected objects

add/remove objects from a list

work with multiple geometries

Tips & Useful Tools

multibody dynamics a, wb1310 1 introduction to adams course manual for multibody dynamics a, wb1310...

Documents

multibody dynamics

model example

model view window example

view view accessories

new model

file export window

hinge example

file import window