Adams Solver Guide

7/28/2019 Adams Solver Guide

1/111

VERSION 12.0

PART NUMBER

120BSOLTR-01

Visit us at:www.adams.com

Basic ADAMS/SolverTraining Guide
http://www.adams.com/http://www.adams.com/


2/111

U.S. Government Restricted Rights: If the Software and Documentation are provided in connection with a

government contract, then they are provided with RESTRICTED RIGHTS. Use, duplication or disclosure issubject to restrictions stated in paragraph (c)(1)(ii) of the Rights in Technical Data and Computer Software

clause at 252.227-7013. Mechanical Dynamics, Incorporated, 2300 Traverwood Drive, Ann Arbor, Michigan

48105.

The information in this document is furnished for informational use only, may be revised from time to time,

and should not be construed as a commitment by Mechanical Dynamics, Incorporated. Mechanical

Dynamics, Incorporated, assumes no responsibility or liability for any errors or inaccuracies that may

appear in this document.

This document contains proprietary and copyrighted information. Mechanical Dynamics, Incorporated

permits licensees of ADAMSsoftware products to print out or copy this document or portions thereof

solely for internal use in connection with the licensed software. No part of this document may be copied for

any other purpose or distributed or translated into any other language without the prior written permission of

Mechanical Dynamics, Incorporated.

2002 by Mechanical Dynamics, Incorporated. All rights reserved. Printed in the United States of America.

ADAMSis a registered United States trademark of Mechanical Dynamics, Incorporated.

All other product names are trademarks of their respective companies.


3/111

3

&RQWHQWV

:HOFRPHWR%DVLF$'$066ROYHU7UDLQLQJ7

About Mechanical Dynamics 8

Content of Course 9

Getting Help at Your Job Site 10

9LUWXDO3URWRW\SLQJZLWK$'$0611

Virtual Prototyping Process 12

Basic ADAMS/Solver Course 13

Four File Types in ADAMS/Solver 14

ADAMS/Solver Dataset File 15

ADAMS/Solver Command File 16

ADAMS/Solver Analysis Files 17

ADAMS/Solver Message File 18Simulating a Model in ADAMS/Solver 19

Workshop 1Process Overview 20

9LHZLQJ5HVXOWV25

PostProcessing Interface Overview 26

Animating 27

Plotting 28

Getting Help 29

Workshop 2Viewing Results 30

)DOOLQJ6WRQH41

System-Level Design 42

Coordinate Systems 43

Part Coordinate System 44

Coordinate System Marker 45

Differences Between Parts and Graphics 46

Parts, Graphics, and Markers 47

Types of Parts in ADAMS 48Part Properties (Mass and Inertia) 49

Graphic Properties 50

Workshop 3Falling Mass 51
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


4/111

4 Content

&217(176

2QH'2)3HQGXOXP57

Constraints 58

Use of Markers in Constraints 59

Three-Point Orientation Method 61

Degrees of Freedom (DOF) 62

Workshop 4One DOF Pendulum 63

/LQHDU6SULQJ'DPSHU,69

Initial Condition Simulation 70

Types of Simulations 71

Simulation Hierarchy 72

Forces in ADAMS 73

Spring Dampers in ADAMS 74

Magnitude of Spring Dampers 75

Workshop 5Spring Damper I 76

/LQHDU6SULQJ'DPSHU,,81

Single-Component Forces: Action-Reaction 82

Functions in ADAMS 83

Measuring Displacement (Functions continued) 84

Measuring Velocity (Functions continued) 85

Workshop 6Spring Damper II 86

%UDNH6\VWHP,91Applying Motion 92

STEP Function 93

REQUESTing Measurement Data 94

Workshop 7Brake System I 95

%UDNH6\VWHP,,105

Multi-Component Forces 106

Incorporating Test Data (Splines) 108

AKISPL Function 109Workshop 8Brake System II 110
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


5/111

Contents

&217(176

%UDNH6\VWHP,,,117

Design Study: Quasi-static 118

Workshop 9Brake System III 119

6XVSHQVLRQ125

Bushings 126

Workshop 10Suspension 127

%RXQFLQJ%DOO143

Modeling Contact: IMPACT Function 144

Workshop 11Bouncing Ball 146

7DEOHV153

Constraints Tables (Incomplete) 154

Forces Tables (Incomplete) 155Constraint Tables (Complete) 156

Forces Tables (Complete) 157

Mass Moments of Inertia 158

6DPSOH'DWDVHWV161

.acf files 162

ball.adm file 163

brake.adm file 164

susp1.adm file 165
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


6/111

6 Content

&217(176
http://-/?-http://-/?-


7/1117

:(/&20(72%$6,&$'$0662/9(575$,1,1

ADAMS is a powerful modeling and simulating environment that lets you

build, simulate, refine, and ultimately optimize any mechanical system, from

automobiles and trains to VCRs and backhoes.

Basic ADAMS/Solver training teaches you how to build, simulate, and refine

a mechanical system using Mechanical Dynamics, Inc.s ADAMS/Solver and

ADAMS/PostProcessor.

:KDWVLQWKLVVHFWLRQ

About Mechanical Dynamics, 8

Content of Course, 9

Getting Help at Your Job Site, 10
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


8/1118 Welcome to Basic ADAMS/Solver Training

$ERXW0HFKDQLFDO'\QDPLFV

)LQGDOLVWRI$'$06SURGXFWVDW

http://www.adams.com/mdi/product/modules.htm

/HDUQDERXWWKH$'$06&$'&$0&$(LQWHJUDWLRQDW

http://www.adams.com/mdi/product/partner.htm

)LQGDGGLWLRQDOWUDLQLQJDW

http://support.adams.com/training/training.html

Or your local support center
http://-/?-http://www.adams.com/mdi/product/modules.htmhttp://www.adams.com/mdi/product/modules.htmhttp://www.adams.com/mdi/product/partner.htmhttp://www.adams.com/mdi/product/partner.htmhttp://support.adams.com/training/training.htmlhttp://support.adams.com/training/training.htmlhttp://-/?-http://support.adams.com/training/training.htmlhttp://www.adams.com/mdi/product/partner.htmhttp://www.adams.com/mdi/product/modules.htm


9/111Welcome to Basic ADAMS/Solver Training 9

&RQWHQWRI&RXUVH

$IWHUWDNLQJWKLVFRXUVH\RXZLOOEHDEOHWR

Build simple ADAMS models.

Understand ADAMS product nomenclature and terminology.

Understand basic modeling principles.

Use the crawl-walk-run approach to virtual prototyping.

Debug your models for the most common modeling challenges (for example,

redundant constraints, zero masses, and so on).

Use and be informed about all methods of ADAMS product support.

Use the product documentation optimally.

2UJDQL]DWLRQRIJXLGH

This guide is organized into modules that get progressively more complex. Each module

focuses on solving an engineering-based problem and covers mechanical system simulation

(MSS) concepts that will help you use ADAMS most optimally. The earlier workshops provide

you with more step-by-step procedures and guidance, while the later ones provide you with less

Each module is divided into the following sections:

1 Problem statement

2 Concepts

3 Workshop

4 Module review
http://-/?-http://-/?-


10/11110 Welcome to Basic ADAMS/Solver Training

*HWWLQJ+HOSDW


11/1111

9,578$/352727


12/11112 Virtual Prototyping with ADAMS

9LUWXDO3URWRW\SLQJ3URFHVV

Build

Test

Validate

Refine

Iterate

Automate

...a model of your design usingBodies ForcesContacts Joints

Motion generators

...your design usingMeasures AnimationsSimulations Plots

...your model byImporting test data

Superimposing test data

...your model by addingFriction Forcing functionsFlexible partsControl systems

...your design throughvariations usingParametricsDesign variables

Validate

Refine

Iterate

Do resultscompare withmeasureddata?

DESIGNPROBLEM

Cut timeand costs

Increasequality

Increaseefficiency

IMPROVEDPRODUCT

...your design usingDOEsOptimization

...your design process usingCustom menusMacrosCustom dialog boxes

Optimize

Automate

No

Yes
http://-/?-http://-/?-


13/111Virtual Prototyping with ADAMS 13

%DVLF$'$066ROYHU&RXUVH

7KUHHVWHSVRIWKHYLUWXDOSURWRW\SLQJSURFHVVWKDWWKLVFRXUVHFRYHUV

Build(design) a virtual prototype of a mechanical system using an ADAMS dataset

file.

Testyour mechanical system using ADAMS/Solver.

Validate (review) the results of your output files using ADAMS/PostProcessor.

Build

Test

Validate

...a model of your design usingBodies Forces

Contacts JointsMotion generators

...your design usingMeasures AnimationsSimulations Plots

...your model by

Importing test dataSuperimposing test data

Validate
http://-/?-http://-/?-



)RXU)LOH7\SHVLQ$'$066ROYHU

'DWDVHWILOHDGPFRQWDLQVVWDWHPHQWVDQGIXQFWLRQV

&RPPDQGILOHDFIFRQWDLQVFRPPDQGVDQGIXQFWLRQV

$QDO\VLVILOHVUHTUHVJUDRXWFRQWDLQVLPXODWLRQRXWSXW

0HVVDJHILOHPVJFRQWDLQVVWDWLVWLFVDERXWVLPXODWLRQRXWSXW

ADAMS dataset

.adm .req

Analysis files

.res

.gra

.out

Command file

.acf

1 - Build (Input) 3 - Validate (Output)

Message file

.msg

2 - Test (ADAMS/Solver)
http://-/?-http://-/?-



$'$066ROYHU'DWDVHW)LOH

'DWDVHWILOHDGPFRQWDLQVVWDWHPHQWVDQGIXQFWLRQV

Statements define an element of a model, such as a part, constraint, or force.

Functions are a numeric expression that define the magnitude of an element, such as

force or motion.Sample .adm file

FunctionStatement

TITLE LINE

!-------------------------------- SYSTEM UNITS --------------

UNITS/FORCE = NEWTON, MASS = KILOGRAM, LENGTH = MILLIMETER,

,TIME = SECOND

!

PART/1, GROUND

!

MARKER/5, PART = 1, QP = 175, -225, 0

!

PART/2, MASS = 70.94, CM = 3, IP = 2.01E+006, 1.80E+005

, 2.01E+006, MATERIAL = steel

!

MARKER/2, PART = 2, REULER = 37.87498365D, 90D, 0D

!

MARKER/3, PART = 2, QP = 175, -225, 0, REULER = 37.87498365D, 0D, 0D

!

GRAPHICS/1, CYLINDER, CM = 2, LENGTH = 570.08, RADIUS = 71.26

!

JOINT/1, REVOLUTE, I = 4, J = 1

!

REQUEST/1, DISPLACEMENT, I = 3, J = 5, RM = 5

ACCGRAV/JGRAV = -9806.65

OUTPUT/REQSAVE, GRSAVE

RESULTS/

!

MOTION/1, ROTATIONAL, JOINT = 1, FUNCTION = 30.0d * time

!

END
http://-/?-http://-/?-



$'$066ROYHU&RPPDQG)LOH

&RPPDQGILOHDFIFRQWDLQVFRPPDQGVDQGIXQFWLRQV

Commands are actions that you issue during an analysis to make changes to your

model or analysis settings.

You can enter commands interactivelyone at a timeor you can enter them from acommand file.

Sample .acf file

model_name.adm

output_name

SIMULATE/STATIC

SIMULATE/DYNAMIC, END=3.0, STEPS=30DEACTIVATE/JOINT, ID=3

SIMULATE/DYNAMIC, DURATION=2.0, STEPS=200

STOP

Command
http://-/?-http://-/?-



$'$066ROYHU$QDO\VLV)LOHV

$QDO\VLVILOHVUHTUHVJUDRXWSURYLGHVLPXODWLRQRXWSXW

The output corresponds to these statements in your dataset: REQUEST, RESULT, GRAPHICS,

and OUTPUT.

5HTXHVWILOHUHTSURYLGHV

Key system measurements:

toe angle or displacement in a local markers coordinate system.

Data for plotting in ADAMS/PostProcessor.

5HVXOWVILOHUHVSURYLGHV

Default calculations in Global Coordinate System:

part displacements and constraint reaction forces

Data for plotting in ADAMS/PostProcessor.

*UDSKLFVILOHJUDSURYLGHV

Data for animating in ADAMS/PostProcessor.

2XWSXWILOHRXWSURYLGHV

Tabular output of request data.
http://-/?-http://-/?-



$'$066ROYHU0HVVDJH)LOH

0HVVDJHILOHPVJFRQWDLQVUXQWLPHVWDWLVWLFVRQVLPXODWLRQRXWSXWLQFOXGLQJ

Warning messages

Error messages

Excerpts from a .msg file

---- WARNING ----

IP data specified for PART test.PAR5200 is not physically

meaningful, since it does not satisfy the requirement

that Iyy + Izz must be greater than or equal to Ixx.

The moments of inertia about the Center of Mass are:

Ixx = 500.80, Iyy = 115.29, Izz = 98.147

---- ERROR ----

The simulation stopped at time = 7.82641E-02.

ADAMS cannot solve the equations of motion.
http://-/?-http://-/?-



6LPXODWLQJD0RGHOLQ$'$066ROYHU

,QWHUDFWLYHPRGH

Non scripted: lets you enter commands one by one.

Scripted: lets you enter commands from the command file (.acf).

%DWFKPRGH

Runs multiple jobs using a log file and one or more command files (.acf).

([DPSOHVRIUXQQLQJLQWHUDFWLYHVLPXODWLRQLQ$'$06RQ81,;DQG17

UNIX shell (what you might type to simulate)

NT DOS shell (what you might type to simulate)

adams12 -c

ru-standard

interactive

my_file.acf

adams12

ru-standard

my_file.acf
http://-/?-http://-/?-



3UREOHPVWDWHPHQW

Simulate a dynamic model and review the associated output files.

0RGHOGHVFULSWLRQ

The model you will use in this workshop represents a quarter-front, short-long-arm (SLA) car

suspension.

:RUNVKRS3URFHVV2YHUYLHZ
http://-/?-http://-/?-



6WDUWLQJ$'$066ROYHU

7RVWDUW$'$066ROYHUIURP\RXU81,;ZRUNLQJGLUHFWRU\

1 Open a UNIX shell and enter the commands to locate and change to your working

directory.

Use the ls command to review a list of files and directories.

Use the cd command to change from one directory to another.

For example, to change your location from the directory, bso_exercises, to mod_01_intro,

enter the following:

cd bso_exercises

lscd mod_01_intro

ls

2 Once you have located your working directory, enter the command to start ADAMS, for

example, adams12 -c.

A text menu appears inside of your command shell window.

At your site, your systems administrator determines the alias to start ADAMS/Solver.In class, ifadams12 -c does not launch ADAMS/Solver, see your class instructor for thecorrect command.

3 Enter ru-standard (or use the shortcut ru-s) to run standard ADAMS/Solver.

4 Enter interactive (or use the shortcut i)to run ADAMS/Solver in interactive mode.Skip to Step 1 in Simulating your model on page 23.

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-



7RVWDUW$'$066ROYHUIURP\RXU17ZRUNLQJGLUHFWRU\

1 Do one of the following:

From the Start menu, point to Programs, and then select Command Prompt.

The Command Prompt window appears.

From the Start menu, select Run and enter cmd.

The Command Prompt window appears.

2 Enter the commands to locate and change to your working directory.

Use the dir command to display your list of files and directories.

Use the cd command to change from one directory to another.

For example, to change your location from the directory, bso_exercises, to mod_01_intro,

enter the following:

cd bso_exercises

dir

cd mod_01_intro

dir

3 Once you have changed to your working directory, enter the command to start ADAMS,for example, adams12.

A text menu appears inside of your Command Prompt window.

At your site, your systems administrator determines the alias to start ADAMS/Solver.In class, ifadams12 does not launch ADAMS/Solver, see your class instructor for thecorrect command.

4 Enter ru-standard (or use the shortcut ru-s) to run standard ADAMS/Solver.

http://-/?-http://-/?-http://-/?-http://-/?-



6LPXODWLQJ\RXUPRGHO

7RVLPXODWH\RXUPRGHO

1 Enter the name of the ADAMS command file sla.acf.

The command file gives ADAMS/Solver instructions on how to simulate your model, for

example, it defines the run time and type of simulation.

2 Enter exit to close the ADAMS menu.

3 To list the files that are in your working directory, enter ls on UNIX or dir on NT.

Your directory should contain more files than before you ran the simulation.

81,;RSWLRQDOWDVNV

Quickly set up and run a simulation entering all of the necessary commands on one

line. For example, from a UNIX prompt, enter:

adams12 -c ru-s i sla.acf exit

17RSWLRQDOWDVNV

Quickly set up and run a simulation entering all of the necessary commands on one

line. For example, from a command prompt, enter:

adams12 ru-s sla.acf




0RGXOHUHYLHZ

1 What are the three categories of syntax used in the ADAMS language?

________________________________________________________________________

2 Which two out of the three are used in the .adm file?

________________________________________________________________________

3 Which two out of the three are used in the .acf file?

________________________________________________________________________

4 In this course, we are going to use ADAMS/Solver to process the results and ADAMS/

PostProcessor to view the results. What are we going to use as a pre-processor?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

5 When you use ADAMS after this course, you will probably be using a pre-processor (that

is, ADAMS/Pre, ADAMS/View, ADAMS/Car, and so on). Why, then, do you need to

learn how to write .adm and .acf files on your own?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________



25/11125

9,(:,1*5(68/76

In this module you will use ADAMS/PostProcessor to manipulate, review, and

refine the results of the suspension model you simulated in the previous module

:KDWVLQWKLVPRGXOH

PostProcessing Interface Overview, 26

Animating, 27

Plotting, 28

Getting Help, 29

Workshop 2Viewing Results, 30

Module review, 40
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


26/11126 Viewing Results

3RVW3URFHVVLQJ,QWHUIDFH2YHUYLHZ

$'$063RVW3URFHVVRUKDVWZRPRGHVGHSHQGLQJRQWKHDFWLYHYLHZSRUW

Animation

Plotting

([DPSOH

The tools in the Main toolbar change if you load an animation or a plot into the viewport

The elements shown above are common to both modes.
http://-/?-http://-/?-


27/111Viewing Results 27

$QLPDWLQJ

Viewport

Reset, Rev, Pause,Animation settings

Slider barDashboard

Treeview

Property

editor

Main toolbar

Fwd, Record

categories

Mode type
http://-/?-http://-/?-



3ORWWLQJ

Viewport

List of simulation results

Types of List of requests/ Manage

results to curves

be displayed

Treeview

Property

editor

Main toolbar

results

Mode type
http://-/?-http://-/?-



*HWWLQJ+HOS

5HIHUHQFLQJWKHRQOLQH$'$066ROYHUJXLGHV

'RLQJJOREDOVHDUFKHVRQDQ\RQOLQH$'$06JXLGH
http://-/?-http://-/?-



3UREOHPVWDWHPHQW

Use ADAMS/PostProcessor to manipulate, review, and refine the results of the suspension

model you simulated in the previous module.

0RGHOGHVFULSWLRQ

This model represents a quarter-front, short-long-arm (SLA) car suspension.

You can use the files you generated in Module 1, or use the ones in the directory,exercise_dir/mod_02_view_results.

:RUNVKRS9LHZLQJ5HVXOWV



6WDUWLQJ$'$063RVW3URFHVVRU

7RVWDUW$'$063RVW3URFHVVRU

1 Go to the directory where your analysis files are stored.

If youre using the files you generated, the directory should be mod_01_intro.

If youre using the files we provided for you, the directory should be

mod_02_view_results.

2 Open the ADAMS Selection menu.

For UNIX, enter adams12 -c.

For NT, enter adams12.

The ADAMS Selection Menu appears.

3 At the command line, enter appt.

The ADAMS/PostProcessor Main window appears.

$ERXWWKH$'$063RVW3URFHVVRUZLQGRZ

ADAMS/PostProcessor has two modes: animation and plotting. It switches its modes

automatically depending on the contents of the active viewport. For example, the tools in the

Main toolbar change if you load an animation or a plot into the viewport.

Figure 1 on page 31 shows a conceptual sketch of the ADAMS/PostProcessor window. The

elements shown are common to both modes.

Figure 1. ADAMS/PostProcessor Window

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-



,PSRUWLQJILOHV

7RLPSRUW\RXUDQDO\VLVILOH

1 From the File menu, point to Import, and then select AnalysisFiles.

The File Import dialog box appears.

2 Right-click the File Name text box, and then select Browse.

The Select File dialog box appears.

3 Select any one of the files that starts with sla_output.

4 In the Select File dialog box, select OK.

5 In the File Import dialog box, select OK.

The graphics representing the initial conditions of your simulation appear in the viewport




9LHZLQJUHVXOWV

7RYLHZDQDQLPDWLRQRIWKHUHVXOWV

Adjust your view of the model on your screen using the tools above the viewport. The

figure below highlights some of the tools that are available. Try experimenting withthe rotate, zoom, and translate tools.

7RSOD\DQDQLPDWLRQRIWKHUHVXOWV

Play an animation of your model using the tools that are located above the viewport

and in the dashboard. Experiment with the play and pause tools.

Select

Dynamic Rotate

Dynamic TranslateCenter

View Zoom

View Fit

Front View

Reset Animation

Play Animation Backward

Pause Animation

Play Animation

Record Animation




0RGLI\LQJWKHJUDSKLFVRI\RXUDQLPDWLRQ

7RPRGLI\WKHJUDSKLFVVHWWLQJVRI\RXUDQLPDWLRQ

Select the View tab in the dashboard.

Your view options appear below the View button.

Experiment with the options that are available.

7RFKDQJHWKHFRORURIWKHZKHHO

1 From the treeview, expand the model by clicking on the + sign.

2 Select PART_5, which is the wheel.

3 Below the treeview, in the property editor, select the arrow next to the Color text box.

4 Select Coral for the color setting.

7RHQODUJHWKHJUDSKLFVWKDWLOOXVWUDWHIRUFH

1 From the Edit menu, select Preferences.

The PPT Preferences dialog box appears.

2 In the Force Scale text box, enter a value that is greater than 1, and then select Enter.

3Experiment with changing the scale of the force graphics.

7RPDNHPRUHJUDSKLFHQKDQFHPHQWV

1 From the same PPT Preferences dialog box, select the Geometry tab, and check the Graphics

Endcaps box.

Selecting the box adds endcaps to cylinders.

2 Change the view from shaded to wireframe.

3 On the top tool bar, select Wireframe/shaded.

Icon Visibility

Wireframe/shaded




3ORWWLQJ

7RSORWWKHWRHDQJOHYHUVXVWLPH

1 Create a new page by clicking the Create a New Page tool above the viewport.

You should now have two pages in your session.

2 Change the viewport to plotting by right-clicking in the viewport, and choosing Load Plot

from the pop-up menu.

Notice how the dashboard changes from animation tools to plotting tools.

3 Create a plot on this page by doing the following:

From the Simulation list, select the only simulation in your session, sla_output.

From the Request list, select REQUEST_2.

From the Component list, select X.

Below the Independent Axis: heading, make sure Time is selected.

Select Add Curves.

Create a New Page

Delete a PagePrevious Page

Next Page




Notice the dashboard settings in the following figure:




7RSORWWKH7RH$QJOHYV9HUWLFDO:KHHO3RVLWLRQQH[WWRDQDQLPDWLRQ

1 Go back to page_1 in ADAMS/PostProcessor.

2 Split the screen by right-clicking on the Page Layout tool above the viewport and choosing

the Split Screen tool.

3 Set the new viewport to Plotting by right-clicking in the viewport and choosing Load Plot

from the pop-up menu.

4 Plot Toe Angle vs. Vertical Wheel Position by doing the following:

In the Simulation list, select the only simulation in your session, sla_output.

In the Request list, select REQUEST_2.

In the Component list, select X.

Below the Independent Axis: heading, toggle Data.

The Independent Axis Browser appears.

In the Request list, select REQUEST_1.

In the Component list, select Z.

Select OK.

Select Add Curves.

Split Screen




7RXVHWKHGRFXPHQWDWLRQWRJHWSORWVWDWLVWLFV

1 From the Help menu, select ADAMS/PostProcessor Guide.

2 Search for the phrase plot statistics and see where it leads you.

If you are unable to find the phrase ask the instructor for help.

3 Use the plot statistics toolbar to find the maximum Toe Angle value.

4 Once you find the maximum toe angle value, use it to answer Question 1 in Module

review on page 40.

7RDQLPDWHWKHPRGHOZKLOHYLHZLQJWKHSORW

1 Left-click the viewport that contains your graphics so the dashboard changes to animation

tools.2 Play an animation.

7RPRGLI\WKHJUDSKLFVRIWKHSORW

1 Modify the plot title by doing the following:

In the treeview, expand page_1 by clicking the + sign.

Select plot_2.

Clear the selection ofAuto Title.

In the Property Editor below, enter the title Toe Angle vs. Wheel Height.

Select Enter.

2 Label the vertical axis as Toe Angle (radians) by doing the following:

In the treeview, expand the plot by clicking the + sign.

select vaxis.

In the Property Editor below, toggle Labels.

Change the label from NO UNITS to Toe Angle (radians).

3 Modify the legend text by doing the following:

In the treeview, select curve_1.




In the Property Editor, change the Legend text box to sla_output.

6DYLQJ

7RVDYH\RXU$'$063RVW3URFHVVRUVHVVLRQ

1 Save your session by doing the following:

From the File menu, select Save As.

Name your file in the File Name text box.

Select OK.

This saves the results from your entire session in one file.

2 Exit ADAMS/PostProcessor by doing the following:

From the File menu, select Exit.

Select Exit, Dont Save.




0RGXOHUHYLHZ

1 What was the maximum toe angle value?

________________________________________________________________________

2 What is the difference between the two search tools (the ones with the binoculars)

available in Adobe Acrobat Reader, which is the software we use to view the online

users guides?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

3 To view an animation, which file type will you need to import?

________________________________________________________________________

4 Both the results (.res) and the request (.req) file can be imported and used to plotinformation. What is the difference between the results (.res) and the request (.req) files?

(You may need to refer back to Virtual Prototyping with ADAMS on page 11 for help on

this.)

________________________________________________________________________

________________________________________________________________________

_______________________________________________________________________



41/1114

)$//,1*6721(

Find the displacement, velocity, and acceleration of a lumped mass after one

second, when it falls under the influence of gravity, with zero initial velocity

:KDWVLQWKLVPRGXOH

System-Level Design, 42

Coordinate Systems, 43

Part Coordinate System, 44

Coordinate System Marker, 45

Differences Between Parts and Graphics, 46

Parts, Graphics, and Markers, 47

Types of Parts in ADAMS, 48

Part Properties (Mass and Inertia), 49

Graphic Properties, 50

Workshop 3Falling Mass, 51

Module review, 56

g
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


42/11142 Falling Stone

6\VWHP/HYHO'HVLJQ

7KHFUDZOZDONUXQDSSURDFK

Do not build the entire mechanism at once.

As you add a new component, make sure that it works correctly.

Check your model at regular intervals.

$YRLGWKHQHHGIRUFRPSOH[GHEXJJLQJE\IROORZLQJWKHFUDZOZDONUXQDSSURDFK
http://-/?-http://-/?-


43/111Falling Stone 43

&RRUGLQDWH6\VWHPV

'HILQLWLRQRIDFRRUGLQDWHV\VWHP&6

A coordinate system is essentially a measuring stick to define kinematic and dynamic

quantities.

7\SHVRIFRRUGLQDWHV\VWHPV

Global coordinate system (GCS):

Rigidly attaches to the ground part.

Defines the absolute point (0,0,0) of your model and provides a set of axes

that is referenced when creating local coordinate systems.

Local coordinate systems (LCS):

Part coordinate systems (PCS)

Markers

Point O

Point P

zG

RR Rxx Ryy Rzz+ +=

xG

yG
http://-/?-http://-/?-



3DUW&RRUGLQDWH6\VWHP

'HILQLWLRQRISDUWFRRUGLQDWHV\VWHPV3&6

Only one exists per part.

Location and orientation is specified by providing its location and orientation with

respect to the GCS.

For the purpose of this class, and because most pre-processors do so, it is recommended that

each parts PCS has the same location and orientation as the GCS.

Global coordinate system

Part coordinate systemPart 1 at location (10, 5.5, 0)

ground body at location (0, 0, 0)

10

5.5

xG

yG

zG

xP1

yP1

zP1
http://-/?-http://-/?-



&RRUGLQDWH6\VWHP0DUNHU

'HILQLWLRQRIDPDUNHU

It attaches to a part and moves with the part.

Several can exist per part.

Its location and orientation can be specified by providing its location and orientation

with respect to PCS.

It is used wherever a unique location needs to be defined. For example:

The location of a parts center of mass.

The reference point for defining where graphical entities are anchored.

It is used wherever a unique direction needs to be defined. For example:

The axes about which part mass moments of inertia are specified.

Directions for constraints.

Directions for force application.

All marker locations and orientations are expressed in PCS.

Part coordinate systemMarker 1 on Part 1at location (-5, -1, 0)

Part 1 at location (10, 5.5, 0)-5-1

xG

yG

zG

xP1

yP1

zP1

Ground Body at location (0, 0, 0)

xM1

yM1

zM1
http://-/?-http://-/?-


46/111



3DUWV*UDSKLFVDQG0DUNHUV

'HSHQGHQFLHVLQ$'$06

To understand the relationship between parts, graphics, and markers in ADAMS, it is

necessary to understand the dependencies shown next:

MARKER/Corner Marker

(CM)

MARKER/Center Marker

(CM)

GRAPHIC/BLOCK

MARKER/Center of Mass

(CM)

GRAPHIC/CYLINDER

PART/

CYLINDER

BLOCK

PART

CM

GRAPHIC CMs
http://-/?-http://-/?-



7\SHVRI3DUWVLQ$'$06

5LJLGERGLHV

)OH[LEOHERGLHVEH\RQGWKHVFRSHRIWKLVFRXUVH

*URXQGSDUW

Must exist in every model.

Defines the GCS and the global origin and, therefore, remains stationary at all times.

Acts as the inertial reference frame for calculating velocities and acceleration.

Are movable parts.

Possess mass and inertia properties.

Cannot deform.

Are movable parts.

Possess mass and inertia properties.

Can bend when forces are applied to them.
http://-/?-http://-/?-



3DUW3URSHUWLHV0DVVDQG,QHUWLD

7KURXJKWKH3$57VWDWHPHQW\RXPXVW

Provide the mass for a rigid body.

Provide the inertia matrix for a rigid body.

Assign mass to a marker that represents the parts center of mass (CM).

Assign inertia to a marker about which the moments of inertia are defined (CM or

IM).

([DPSOH

PART/20, MASS = 63.71, CM = 2000, IP = 1.50E5, 1.68E6, 1.68E6

MARKER/2000, PART = 20, QP = -75, 200, 0

ADAMS willnot use the dimensions of the graphics to define the mass and inertia.

No IM marker was defined in this example, therefore, the CMs orientation is

referenced for inertia.

Inertia can be calculated for some simple shapes using the Mass Moments of Inertia

sheet in Tables on page 153.

Many pre-processors leave the QG argument out of the statement (as seen above),

which is the equivalent to it being all zeros.

X

Z

YMARKER/2000

(center of mass)
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-



*UDSKLF3URSHUWLHV

7KURXJKWKH*5$3+,&VWDWHPHQW\RXPXVW

Define the shape type (cylinder, circle, and so on).

Provide the dimensions for the chosen shape.

Assign graphic to a marker, which defines:

which part the graphic will follow

the location of the graphic

the orientation of the graphic

([DPSOH&



3UREOHPVWDWHPHQW

Find the displacement, velocity and acceleration of a lumped mass after one second, when it

falls under the influence of gravity, with zero initial velocity.

MASS

g

mass=1kg

radius=50mm

:RUNVKRS)DOOLQJ0DVV
http://-/?-http://-/?-http://-/?-



&UHDWLQJWKHPRGHOGDWDVHW

7RFUHDWHWKHPRGHOGDWDVHWEDVHGRQWKHILJXUHJLYHQ

1 Go to the/mod_03_falling_stone directory.

2 Open a text editor to create a new file.

UNIX: Use jot or vi.

NT: Use Notepad or WordPad.

3 Define the title by entering ! Falling Stone Model on the first line of the dataset.

4 Define the units by entering UNITS/.

To get help with the various statements, go to the ADAMS online documentation, andopen the guide, Using ADAMS/Solver.

5 Define the acceleration due to gravity for the model by entering ACCGRAV/.

6 Create the ground part by entering PART/.

7 Create the stone part by entering PART/, and defining the mass, inertia, and location of

center of mass.

The inertia can be calculated using the Mass Moments of Inertia sheet in Tables on

page 153.8 Define the location of the center of mass to be at the global origin by entering MARKER/.

9 Create a circle graphic to represent the stone by entering GRAPHICS/.

Use the CM marker for the part and the CM marker for the graphic.

10 Generate a graphics (.gra) file for animating later by entering OUTPUT/GRSAV.

11 Generate a results (.res) file for plotting later by entering RESULTS/.

12Signify that this is the end of the dataset by entering END.

13 Save the file as stone.adm in the mod_03_falling_stone directory.

:RUNVKRS)DOOLQJ0DVV



6LPXODWLQJWKHPRGHO

In this section, you will create a command file (*.acf) to dynamically simulate the model for

1 second with 100 output steps.

7RVLPXODWHWKHPRGHO

1 Open a text editor.

2 Enter stone.admas the first line of the command file.

This is the name of the .adm file you are going to simulate.

3 Enter stone_output as the second line of the command file.

This is the name that you want assigned to your output files.

4 Enter SIMULATE/DYNAMICS, END=1, STEPS=100 as the third lineof your command file.

To get help with the various commands, go to the ADAMS online documentation.

5 Enter STOP to signify the end of the commands.

6 Save the file as stone.acf.

7 Run the simulation.

Ensure that the file was simulated properly (no errors or unexpected warning messages).

3ORWWLQJUHVXOWV

7RSORWWKHUHVXOWV

1 Open ADAMS/PostProcessor.

2 Import the stone_output Solver analysis files (.req, .res, .gra).

Because you did not generate a .req file, ADAMS/PostProcessor only imports the .res and

.gra files.

3 Animate the model to ensure the movement you expected.

4 Create a new page.

5 Right-click in the viewport and select Load Plot.

6 Set Source to Result Sets.

7 Choose the part whose results you want to plot.

:RUNVKRS)DOOLQJ0DVV



8 Above the Add Curves button, on the right side of the dashboard, toggle the Surf tool.

Surf lets you view a selected result component without using the Add Curves button.

9 Now, select different components from the Component section and see the plot refresh

with each new selection.

6ROYLQJIRUWKHSUREOHPVWDWHPHQW

7RVROYHIRUWKHSUREOHPVWDWHPHQW

1 Find the value of the stones displacement after 1 second. Use the plot tracking tool on the

ADAMS/PostProcessor main toolbar.

2 Determine if this result makes sense.

If not, check for mistakes in your model and correct them.

3 If the results do make sense, answer Question 1 in the Module review on page 56.

4 Find the value of the stones velocity after 1 second.

Use it to answer Question 2 in the Module review, 56.

5 Find the value of stones acceleration after 1 second.

Use it to answer Question 3 in the Module review, 56.

6 Exit ADAMS/PostProcessor without saving the session.

2SWLRQDOWDVNV

7RFKDQJHWKHIDOOLQJVWRQHWRDSURMHFWLOH

1 Edit the stone.adm file so that the part has an initial velocity of6 m/sec, at an angle of60o

with respect to the horizontal.

Use VX and VY parameters for the PART/statement.

Plot Tracking

:RUNVKRS)DOOLQJ0DVV
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-



2 Save the file as projectile.adm.

3 Edit the stone.acf file, so that it will run the new file, projectile.adm.

4 Save the file as projectile.acf.

5 Simulate the model.

6 Animate and plot to see the stones new displacement and velocity values.

$'$06UHVXOWV

Displacement after 1 sec = -4903.3 mm

Velocity after 1 sec =-9806.6 mm/sec

Acceleration after 1 sec = -9806.6 mm/sec2

&ORVHGIRUPVROXWLRQ

$QDO\WLFDOVROXWLRQ

s = (at2) = 4903.325 mm

v = at = 9806.65 mm/sec

a= g = 9806.65 mm/sec2

:KHUH

s = Distance (mm)

a = Acceleration (mm/sec2)

t = Time (sec)

v = Velocity (mm/sec)

:RUNVKRS)DOOLQJ0DVV



0RGXOHUHYLHZ

1 What is the stones displacement after one second?

________________________________________________________________________

2 What is the stones velocity after one second?

________________________________________________________________________

3 What is the stones acceleration after one second?

________________________________________________________________________

4 What do many pre-processors write for the QG argument in the PART/statement?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

5 The CM argument appears in both the PART/statement and certain GRAPHIC/

statements. What is the difference in each case?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

6 Can the CM be the same marker in both the PART/statement and the GRAPHIC/

statement?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

:RUNVKRS)DOOLQJ0DVV


57/11157

21('2)3(1'8/80

Find the initial force supported by the pin at A, for a bar that swings in a vertical

plane about a pivot, given the initial angular displacement (o).

qo=45o

mass=1 kgradius=25 mmlength=250 mm

g

A

:KDWVLQWKLVPRGXOH

Constraints, 58

Use of Markers in Constraints, 59

Three-Point Orientation Method, 61

Degrees of Freedom (DOF), 62

Revolute Joint, DOF Removed by, 154

Workshop 4One DOF Pendulum, 63

Module review, 68
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


58/11158 2QH'2)3HQGXOXP

&RQVWUDLQWV

'HILQLWLRQRIDFRQVWUDLQW

Restricts relative movement between parts.

Represents idealized connection.

Removes rotational and/or translational DOF from a system.

([DPSOH

7UDQVODWLRQDOFRQVWUDLQWVRIWKHKLQJH

5RWDWLRQDOFRQVWUDLQWVRIWKHKLQJH

(about x-axis)

(about y-axis)

Therefore,

Wall

Door

Wall

Door

Zw

Xw

Yw

ZD

XD

YD

XD XW 0=

YD YW 0=

ZD ZW 0=

D W 0=

D W 0=

D and W are free
http://-/?-http://-/?-


59/1112QH'2)3HQGXOXP 59

8VHRI0DUNHUVLQ&RQVWUDLQWV

&RQVWUDLQWHTXDWLRQVLQ$'$06

Constraints are represented as algebraic equations in ADAMS/Solver.

These equations describe the relationship between two markers.

Joint parameters, referred to as I and J markers, define the location, orientation, and

the connecting parts:

First marker, I, is fixed to the first part.

Second marker, J, is fixed to the second part.

$QDWRP\RIDFRQVWUDLQWLQ$'$06

JOINT/0120(hinge)

PART/20(door)

PART/01(wall)

MAR/2001(I marker)

MAR/0101(J marker)

Model(example.adm)
http://-/?-http://-/?-


60/11160 2QH'2)3HQGXOXP

8VHRI0DUNHUVLQ&RQVWUDLQWV

The I and J markers referenced in the joint (and therefore, the parts to which they

belong), move with respect to each other as follows:

The I and J markers overlap at time = 0.

During simulation, the z-axes of both markers stay aligned.

([DPSOH5HYROXWH-RLQW,DQG-PDUNHUV

JOINT/0120, REVOLUTE, I=0103, J=2003

MAR/0103, PART=01, QP = 3,5,0

MAR/2003, PART=20, QP = 3,5,0

zi zj,

y i yj

x i

xj

zi zj,

xi xj,

yi yj,

PART/01

PART/20

MAR/0103

MAR/2003

The Magical Cactus
http://-/?-http://-/?-


61/1112QH'2)3HQGXOXP 6

7KUHH3RLQW2ULHQWDWLRQ0HWKRG

You can define a coordinate systems orientation using two methods:

Rotation sequence method (Euler angles). See the guide, Using ADAMS/Solver for

more details.

Three-point method.

'HILQHWKHRULHQWDWLRQRIDFRRUGLQDWHV\VWHPXVLQJWKHWKUHHSRLQWPHWKRG

In the MARKER/statement, definethree points:

QP - origin of the coordinate system

ZP - coordinates of a point that you want the z-axis to point at

XP - coordinates of a point that you want the x-axis to point at

([DPSOH0$5.(5

MARKER/2003, PART=20, QP=3, 5, 0, ZP=9, 5, 0, XP=3, 10, 0

Zm

Xm

Ym

Yg

ZgXg

QP (3,5,0)

XP (3,10,0)

ZP (9,5,0)

(0,0,0)
http://-/?-http://-/?-


62/11162 2QH'2)3HQGXOXP

'HJUHHVRI)UHHGRP'2)

&RQVWUDLQWVDQG'2)

Each DOF corresponds to at least one equation of motion.

A freely floating rigid body in three-dimensional space is said to have six DOF.

A constraint removes one or more DOF from a system, depending on its type.

'HWHUPLQHWKHQXPEHURIV\VWHP'2)

ADAMS/Solver will provide an estimated number of system DOF by using the

Grueblers Count:

ADAMS/Solver also provides the actual number of system DOF, as it checks to see

whether:

Appropriate parts are connected by each constraint.

Correct directions are specified for each constraint.

Correct type of DOF (translational versus rotational) are removed by each

constraint.

Redundant constraints exist in the system.

Rigid body

zx

y

System DOF = number of movable parts 6 DOF/ part( )

# Constraints # DOF (Constraint)[ ]i type=
http://-/?-http://-/?-


63/1112QH'2)3HQGXOXP 63

3UREOHPVWDWHPHQW

Find the initial force supported by the pin at A for a bar that swings in a vertical plane about a

pivot, given the initial angular displacement, o.

o=45o

mass=1kgradius=25mm

length=250mm

g

A

:RUNVKRS2QH'2)3HQGXOXP
http://-/?-http://-/?-


64/11164 2QH'2)3HQGXOXP



1 Change to the/mod_04_pendulum directory.

2 Open a text editor:


NT: Use Microsoft Notepad or WordPad.

3 Enter ! Pendulum Model as the first line of the dataset.

This is the title.

4 Define the units by entering UNITS/.

5 Define the acceleration due to gravity by entering ACCGRAV/.


7 Create the pendulum part by entering PART/and setting the inertia properties.

8 Define the location and orientation of the center of mass by entering MARKER/.

Location is very important in this model because the pendulum is going to start at an

angle.

Orientation is also important because the inertia values (Ixx, Iyy, and Izz) are not allthe same for this part. In the last module, you created a sphere (where: Ixx = Iyy = Izz).

A cylinder is not that simple. In addition, the orientation is dependent on the initial

conditions of the part.

To define the orientation, use the three-point method.

9 Create a cylinder graphic to represent the pendulum by entering GRAPHICS/.

10 Define the location and orientation of the center marker for the cylinder graphic by

entering MARKER/.

The orientation for this marker is dependent on the initial conditions for the cylinder.

Again, use the three-point method.

11 Generate a graphics (.gra) file for output by entering OUTPUT/GRSAV.

12 Generate a results (.res) file for output by entering RESULTS/.



65/1112QH'2)3HQGXOXP 65

13 Signify that this is the end of the dataset by entering END.

14 Save the file as pendulum.adm in the mod_04_pendulum directory.

7HVWLQJWKHPRGHO

7RFUDZOZDONUXQWHVWWKHPRGHOVRIDU

1 Create a command file (*.acf) to dynamically simulate the model for 1 second with

50 output steps.

2 Run the simulation.


3 View the animation to visually check for errors.

At this point you have no constraints in the model, so the pendulum should just fall.

But you can check your initial conditions and make sure they are acceptable.

You may want to turn on the global triad in ADAMS/PostProcessor.

Toggle the View button in the dashboard below your viewport.

Check the Display Triad box.

4 If anything in the results does not make sense, modify your .adm file.

&RQVWUDLQLQJWKHSHQGXOXP

7RFRQVWUDLQWKHSHQGXOXP

1 Open a text editor to modify your .adm file.

2 Create the appropriate joint between the pendulum and ground by entering JOINT/.

3 Create the I marker for the constraint by entering MARKER/.

4 Create the J marker for the constraint by entering MARKER/.

5 Run the simulation and check your results.

6 Plot the FX and FY components of force for the revolute joint.

Use the values to answer Question 1 in the Module review on page 68.



66/11166 2QH'2)3HQGXOXP



67/1112QH'2)3HQGXOXP 67

2SWLRQDOWDVNV

7RDGGIRUFHJUDSKLFV

Visualize the reaction forces in the joint by entering GRAPHICS/.

7RYLHZWKHDQLPDWLRQDQGWKHSORWVDWWKHVDPHWLPH

1 Right-click the Page Layout tool.

2 Choose a layout that has enough viewports to view your plots and the animation.

3 In the viewport where you would like to put your animation, right-click and select Load

Animation.

4 In the other ports, right-click and select Load Plot.

5 Set up your plots (if they are not set up already).

6 Animate the results.

7 You may need to modify the scale of the force graphics in ADAMS/PostProcessor.

From the Edit menu, select Preferences.

In the PPT Preferences dialog box, in the upper left corner, toggle Animation.

To modify the scale, from the upper right corner use the Force and Torque Scale text

boxes.



68/11168 2QH'2)3HQGXOXP

0RGXOHUHYLHZ

1 What are the initial values of force in the global x and y directions?

________________________________________________________________________

2 If a markers QP=10,14,2, and you want its z-axis to point in the global y direction, what

could ZP equal?

________________________________________________________________________

3 In the JOINT/statement, how do you indicate which two parts are being connected?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________



69/11169

/,1($5635,1*'$03(5,

Investigate the linear spring-damper system shown in the following figure, using

different types of simulations in ADAMS.

MASS

kc

g

:KDWVLQWKLVPRGXOH

Initial Condition Simulation, 70

Types of Simulations, 71

Simulation Hierarchy, 72

Forces in ADAMS, 73

Spring Dampers in ADAMS, 74

Magnitude of Spring Dampers, 75

Workshop 5Spring Damper I, 76

Module review, 80
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


70/11170 /LQHDU6SULQJ'DPSHU,

,QLWLDO&RQGLWLRQ6LPXODWLRQ

'HILQLWLRQRILQLWLDOFRQGLWLRQVVLPXODWLRQ

Attempts to resolve any conflicts in the initial conditions specified for the entities in

the model (for example, broken joints).

Is also known as an assemble simulation.

,QLWLDOORFDWLRQDQGRULHQWDWLRQRISDUWV

You specify the initial position and orientation for a part when you create it.

For a part to be held fixed during the initial condition simulation, you can specify up

to three positions ( ) and up to three orientations (psi, theta, phi).

To do so, use the EXACTargument in thePART/statement

Use initial positions sparingly. If you fix the initial positions of too many parts, theinitial conditions simulation can fail.

([DPSOH,QLWLDOFRQGLWLRQVFRPPDQG

SIMULATE/INTIAL_CONDITIONS

xG yG zG, ,
http://-/?-http://-/?-


71/111/LQHDU6SULQJ'DPSHU, 7

7\SHVRI6LPXODWLRQV

6WDWLF

'\QDPLF

.LQHPDWLF

System DOF > 0.

System velocities and accelerations set to zero.

Can fail if the static solution is a long way fromthe initial condition.

([DPSOHSIMULATE/STATIC

System DOF > 0.

Driven by a set of external forces and excitations.

Nonlinear differential and algebraic equations

(DAEs) are solved.

([DPSOHSIM/DYNAMIC, END=1, STEP=100

System DOF = 0.

Driven by constraints (motions).

Only constraint (algebraic) equations are beingsolved.

Calculate (measure) reaction forces in constraints.

([DPSOHSIM/KINEMATIC, END=1, STEP=100
http://-/?-http://-/?-



6LPXODWLRQ+LHUDUFK\

Often a linear simulation is preceded by a static equilibrium or dynamic simulation. We

are not going to use linear simulations in the next workshop.

Initial Condition Simulation

Transient* Static*

Kinematic* Dynamic*

Nonlinear

MotionStudy Equilibrium

Nonlinear

DOF = 0 DOF > 0

* Automatically performs an assemble simulation

Linear

Eigensolution

or State Matrices

Linear

Calculation(s)

Initial Condition
http://-/?-http://-/?-



)RUFHVLQ$'$06

'HILQLWLRQRIIRUFHV

Try to make parts move in certain ways.

Do not perfectly connect parts together the way constraints do.

Do not absolutely prescribe movement the way motion drivers do.

Neither add nor remove DOF from a system.

&KDUDFWHULVWLFVRIIRUFHV

The characteristic: Defines:

Bodies Which parts are affected

Points of application Where the parts are affected

Vector components How many vector components there are

Direction/Orientation How the force is oriented

Magnitude Whether the force is pre-defined or user-defined
http://-/?-http://-/?-



6SULQJ'DPSHUVLQ$'$06

'HILQLWLRQRIVSULQJGDPSHUV

&KDUDFWHULVWLFVRIVSULQJGDPSHUV

See also: Characteristics of a translational and rotational spring damper, page 155.

They are pre-defined forces.

They represent compliance:

Between two bodies.

Acting over a distance.

Along or about one

particular direction.


Bodies Two (A, B)

Points of application Two (I and J marker)

Vector components One

Orientation (only fortranslational)

Acts along the line of sight between the I and J markers

Positive force repels the two parts

Negative force attracts the two parts

MagnitudePre-defined equation based on stiffness and damping

coefficients (linear)

I marker

J marker

BA

(+)



0DJQLWXGHRI6SULQJ'DPSHUV

0DJQLWXGHEDVHGRQVWLIIQHVVDQGGDPSLQJFRHIILFLHQWV

Linear spring-damping relationship can be written as:

ForceSPDP = k(q - L0) c + F0

where:

q - Distance between the two locations that define the spring damper

- Relative speed of the locations along the line-of-sight between them

k - Spring stiffness coefficient (always > 0)

c - Viscous damping coefficient (always > 0)

F0 - Reference force of the spring (preload)

L0 - Reference length (at preload, always > 0)

Spring damper forces become ill-defined if endpoints become coincident because of

undefined direction.

([DPSOH7UDQVODWLRQDO6SULQJ'DPSHU,DQG-PDUNHUV

SPRINGDAMPER/0120, I=0107, J=2006, K=5, C=.1, L=400, TRANSLATION

MAR/0107, PART=01, QP=0,100,0

MAR/2006, PART=20, QP=0,500,0

q

q

Fk= k(q-L0) +

Fk

kL0+F0

F0

L0

r

-k

free length

c

Fc

Fc = c(dq/dt)

dq/dt

Linear Spring Linear Damper
http://-/?-http://-/?-



3UREOHPVWDWHPHQW

Investigate the linear spring-damper system shown in the following figure, using different types

of simulations in ADAMS.

MASS

k=5.0 N/mmc=0.05N-sec/mm

Lo=400mm g

m=187.224kg

:RUNVKRS6SULQJ'DPSHU,
http://-/?-http://-/?-





1 Change to the /mod_05_springdamper_1 directory.

2 Open a text editor.


NT: Use Microsoft Notepad or WordPad.

3 Enter ! SpringDamper Model as the first line of the dataset.

This is the title.

4 Enter UNITS/to define the units.

5 Enter ACCGRAV/to define the acceleration due to gravity for the model.


7 Create the mass part by entering PART/.

Because you are going to constrain the mass with a translational joint, you dont needinertia properties.

8 Define the location of the center of mass by entering MARKER/.

9 Enter GRAPHICS/to create a circle graphic representing the mass.

10 Define the location and orientation of the center marker for the circle graphic by entering

MARKER/.

Orientation is very important for this graphic.

11 Enter JOINT/to constrain the mass to move only in the Global-Y direction using a

translational joint.

12 Create the I marker for the translational joint by entering MARKER/.

The orientation of the I and J markers are what define the orientation of the joint.

13 Answer Question 1 in the Module review on page 80.

14 Create the J marker for the translational joint by entering MARKER/.

15 Enter OUTPUT/GRSAV to generate a graphics (.gra) file for output.




16 Enter RESULTS/to generate a results (.res) file for output.

17 Signify that this is the end of the dataset by entering END.

18 Save the file as spring_1.adm in the mod_05_springdamper_1 directory.

7HVWLQJWKHPRGHO


1 Create a command file (spring_1dyn.acf) to dynamically simulate the model for 2 seconds

with 50 output steps.



3 Play the animation to visually check for errors.

Because you have only the translational joint in the model, the mass should just fall.

4 If needed, modify your .adm file.

+DQJLQJWKHPDVV

7RKDQJWKHPDVVIURPDVSULQJDQGGDPSHULQSDUDOOHO

1 Open a text editor to modify your .adm file.

2 Create a spring between the mass and ground by entering SPRINGDAMPER/.

3 Create the I marker for the spring by entering MARKER/.

If the I marker is going to be on the mass, then you could just use the center of mass marker

4 Create the J marker for the spring by entering MARKER/.

The J marker should be located 400 mm above the I marker.5 Save the file.

6 Run a dynamic simulation.

7 View the animation of the model.

Does the animation make sense?




8 Plot the Magnitude of Force in the SpringDamper vs. the Position of the Mass Part.

9 Answer Question 2 in the Module review on page 80.

)LQGLQJWKHVSULQJGDPSHUIRUFH

7RILQGWKHVSULQJGDPSHUIRUFHDWVWDWLFHTXLOLEULXP

1 Run an equilibrium simulation.

2 Create a new command file (spring_1static.acf) to find the static equilibrium.


4 Using the Result Sets as the source, plot the spring dampers force magnitude (FMAG).

The results of an equilibrium simulation, may be just one data point; therefore, if you usethe Plot Tracking tool, it is easier to find the value of the single point.

5 Use the values to answer Question 3 in the Module review on page 80.

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-



2SWLRQDOWDVNV

1 Use the GRAPHICS/command to add a graphic to visualize the spring (coils, and so on).

2 Use the GRAPHICS/command to add graphics to see the reaction forces on the I and J

markers of the spring.

3 When you animate the results, you may need to modify the scale of the force graphics in

ADAMS/PostProcessor.

From the Edit menu, select Preferences.

In the upper left corner of the PPT Preferences dialog box, select Animation.

To modify the scale, use the Force and Torque Scale text boxes in the upper right

corner.

0RGXOHUHYLHZ

1 Which axis of theI and J markers defines the axis of translation for the translational joint?

________________________________________________________________________

2 What is the approximate slope of the Spring Force versus Mass Position plot? Does this

value make sense?

________________________________________________________________________

________________________________________________________________________________________________________________________________________________

3 What is the value of spring damper force at static equilibrium?

________________________________________________________________________



81/1118

/,1($5635,1*'$03(5,,

Replace the linear spring damper created in the previous module with a single-

component force that enables you to provide an equation that describes the force

magnitude, allowing for more flexibility.

MASS

F=-k*(q-Lo)-c*q.

g

:KDWVLQWKLVPRGXOH

Single-Component Forces: Action-Reaction, 82

Functions in ADAMS, 83

Measuring Displacement (Functions continued), 84

Measuring Velocity (Functions continued), 85

Workshop 6Spring Damper II, 86

Module review, 89
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


82/11182 /LQHDU6SULQJ'DPSHU,,

6LQJOH&RPSRQHQW)RUFHV$FWLRQ5HDFWLRQ

&KDUDFWHULVWLFVRIDQDFWLRQUHDFWLRQVLQJOHFRPSRQHQWIRUFH6)25&(

They are user-defined forces.

They represent forces:

Between two bodies.

Acting over a distance.

Along or about one

particular direction.

See also: Characteristics of an action-reaction S-force, page 155

ADAMS applies action and reaction forces to the I and J markers that are created.


Bodies Two (A, B)

Points of application Two (I and J markers)

Vector components One

Orientation Acts along the line of sight (between the I and J

markers)

Positive force repels the two parts

Negative force attracts the two parts

Magnitude User-defined

Sforce

I marker

(+)

BA

J marker


83/111/LQHDU6SULQJ'DPSHU,, 83

)XQFWLRQVLQ$'$06

'HILQLWLRQRIIXQFWLRQVLQ$'$06

You use functions to define magnitudes of input vectors used in motions and applied

forces.

Every function evaluates to a single value at each particular point in time.

Motions can only be a function of time:

M = f(time)

Applied forces can be a function of just about any measurement in your model

F = f(displacement, velocity, reaction force in a joint, ...)

([DPSOH6)25&(UHSUHVHQWLQJDGUDJIRUFH

SFORCE/2080, I=2010, J=8013, TRANSLATIONAL

, FUNCTION = 0.5*0.0032*(VX(2010, 8013, 8013)**2)*1.4*19.3

The equation for drag force looks like:

Fdrag1

2--- Vx( )

2C

DA

=
http://-/?-http://-/?-



0HDVXULQJ'LVSODFHPHQW)XQFWLRQVFRQWLQXHG

'LVSODFHPHQWIXQFWLRQV

Translational displacement returns scalar portions of vector components

(measurements are taken to a marker (I) from another (J), resolved in Rs CS), as

shown in the example below.

Rotational displacement returns angles associated with a particular rotation sequence.

6\QWD[IRUWUDQVODWLRQDOGLVSODFHPHQWIXQFWLRQV

DM(I,J)

DX, DY, DZ(I,J,R)

([DPSOH

DY(I,J,R)

R

yR x

R

DX(I,J,R)

DM(I,J)I J

(-)(+)

y y

x x
http://-/?-http://-/?-



0HDVXULQJ9HORFLW\)XQFWLRQVFRQWLQXHG

'HILQLWLRQRIYHORFLW\IXQFWLRQV

Returns scalar portions of velocity vector components (translational or rotational).

6\QWD[IRUWUDQVODWLRQDOYHORFLW\IXQFWLRQV

VM(I,J)

VR(I,J)

VX, VY, VZ(I,J,R,L)

The velocity function, VR, is used to define velocity along the line of sight, which is

commonly used in spring dampers.

If the markers are separating: VR > 0.

If the markers are approaching: VR < 0.
http://-/?-http://-/?-



3UREOHPVWDWHPHQW

Replace the linear spring damper created in the previous module with a single-component force

that enables you to provide an equation that describes the force magnitude, allowing for more

flexibility.

MASS

F=-k*(q-Lo)-c*qg.

:RUNVKRS6SULQJ'DPSHU,,
http://-/?-http://-/?-



*HWWLQJVWDUWHG

7RJHWVWDUWHG

1 Copy the .adm and .acf files from that last module to the directory,

/mod_06_springdamper_2.

If you did not finish the last module workshop, you can use the files that are provided in the

completed directory in mod_05_springdamper_1. You should copy those to the

mod_06_springdamper_2 directory.

UNIX: Make sure the current directory is /mod_05_springdamper_1

directory and use the cp command.

cp *.adm *.acf. ./mod_06_springdamper_2

This UNIX command copies (cp) all files that end with .adm and .acf to a particular directory(mod_06_springdamper_2).

NT: Use the mouse and the exploring capabilities to move files.

2 Change to the /mod_06_springdamper_2 directory.

(GLWLQJWKHPRGHOGDWDVHW

7RHGLWWKHPRGHOGDWDVHWEDVHGRQWKHILJXUHJLYHQ

1 Open your .adm file in a text editor.

2 Enter ! SPRINGDAMPER/to comment out the SPRINGDAMPER/ statement lines that you

created during the first module.

3 Add a single-component force that will behave exactly as the spring did, by entering

SFORCE/:

Use the same I and J markers you used with the SPRINGDAMPER/.

The function syntax should be:

where q = DM( _ , _ ) and qdot = VR( _ , _ )

For help with the DM and VR functions, look them up in the guide, Using ADAMS/

Solverin the Functions section.

4 Save the file as spring_2.adm in the mod_06_springdamper_2 directory.

k q Lo

( ) cq




7HVWLQJWKHPRGHO


1 Edit the command file, spring_1dyn.acf to dynamically simulate the new model

spring_2.adm.



3 Play the animation to visually check for errors.

4 If needed, modify your .adm file.

)LQGLQJWKHVSULQJGDPSHUIRUFH

7RILQGWKHVSULQJGDPSHUIRUFHDWVWDWLFHTXLOLEULXP

1 Edit the command file, spring_1static.acf, to find the static equilibrium of the model

spring_2.adm.

2 Run an equilibrium simulation.


4

Using the result sets as the source, plot the SFORCEs force magnitude (FMAG).5 Use the values to answer Question 1 in the Module review on page 89.

2SWLRQDOWDVNV

7RXQGHUVWDQGWKHIUHHGRPRIXVLQJXVHUGHILQHGIRUFHVPDNHWKHVSULQJGDPSHUQRQOLQHDU

Change the single-component force so that its function describes a nonlinear force.

For example, add an exponential to the deformation portion of the force:

F k q Lo

( )2

cq

=




0RGXOHUHYLHZ

1 Does the force magnitude at static equilibrium equal the value that was derived in the

previous module?

________________________________________________________________________

2 What is the benefit of using an SFORCE/instead of a SPRINGDAMPER/?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

3 What is the drawback of using an SFORCE/instead of a SPRINGDAMPER/?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________



91/1119

%5$.(6


92/11192 Brake System

$SSO\LQJ0RWLRQ

$'$06SURYLGHVWZRW\SHVRIPRWLRQV

Joint motion

Point motion (marker based)

-RLQWPRWLRQ

There are two types:

Translational: applied to translational or cylindrical joints (removes 1 DOF)

Rotational: applied to revolute or cylindrical joints (removes 1 DOF).

You define the joint to which motion is applied.

ADAMS uses the joints I and J markers and a single DOF.

You define motion magnitude as a:

Displacement function of time

Velocity function of time

Acceleration function of time

([DPSOH-RLQW'LVSODFHPHQW-RLQW0RWLRQJOINT/2010, REVOLUTE, I=2011, J=1011

MOTION/2010, JOINT=2010, DISPLACEMENT, FUNCTION=80D*sin(360D*time)
http://-/?-http://-/?-


93/111Brake System I 93

67(3)XQFWLRQ

'HILQLWLRQRID67(3IXQFWLRQ

In ADAMS, the STEP function approximates an ideal mathematical step function

(but without the discontinuities).

Avoid discontinuous functions because they lead to solution convergence difficulties.

The STEP function steps quantities, such as motions or forces, up and down, or on

and off.

A STEP function is used when a value needs to be changed from one constant toanother.

6\QWD[IRU67(3IXQFWLRQ

STEP (q, q1, f1, q2, f2)

where:

q - Independent variable

q1 - Initial value for q

f1 - Initial value for f

q2 - Final value for q

f2 - Final value for f

([DPSOH

STEP (time,1,5,3,10)

Time

q1 < q2
http://-/?-http://-/?-



5(48(67LQJ0HDVXUHPHQW'DWD

'HILQLWLRQRID5(48(67

Indicates a set of data you want written to the request (.req) file.

7KHUHDUHWZRW\SHVRI5(48(67V

Pre-defined

Displacements

Reaction forces

And so on

User-defined

User-written functions

User-written subroutines

:K\XVH5(48(67VLQVWHDGRI5(68/7V"

Results (.res) files do not allow you to write your own functions to be evaluated

during the simulation.

Results (.res) files are often very large. A large amount of CPU time can be spentgenerating the data in these files, when you may only be concerned with certain

measurements.

([DPSOH3UHGHILQHG5(48(67

REQUEST/01, DISPLACEMENT, I=0201, J=0103

, COMMENT=CRANK CENTER OF MASS DISPLACEMENT

Requesting the displacement ofMAR/0201 with respect to MAR/0103.

When you import the .req file into ADAMS/PostProcessor, it offers you all

translational and rotational components (x,y,z,mag) of displacement.

You will also see the COMMENT in ADAMS/PostProcessor if you include one.
http://-/?-http://-/?-



3UREOHPVWDWHPHQW

Constrain the given brake system, and approximate the effort (force) required to fully engage

the brake.

0RGHOGHVFULSWLRQ

The given model is a simplified model of a brake system that currently has three parts

and the associated graphics defined.

In addition, there is a single-component force (SFORCE) already defined that

describes a linear force between the cylinder and ground. The SFORCE represents the

tension in the brake cable.

You are going to add constraints to the brake system.

*HWWLQJVWDUWHG

7RJHWVWDUWHG

1 Change to the /mod_07_brake_1 directory.

2 Simulate the given model.

Use the given files, brake.adm and brake.acf.

Pedal

Cylinder

Connecting RodCable Tension

:RUNVKRS%UDNH6\VWHP,
http://-/?-http://-/?-



3 View the animation in ADAMS/PostProcessor.

You should see the connecting rod and pedal fall due to gravity.

The cylinder will swing around some but it should not fall off of the screen because it is

attached to the SFORCE that is described in the Model Description on page 95.

*HWWLQJWRNQRZWKHPRGHO

(Pedal)

PART/10

PART/30

(Connecting Rod)

PART/20

(Cable Tension)SFORCE/3001

(0,0,0)

(-225,-150,0)(-175,-150,0)

(-125,-150,0)

(25,-300,0)

(100,-500,0)

(16.33,-200,0)

(Cylinder)




&RQVWUDLQLQJWKHPRGHO

7RFRQVWUDLQWKHPRGHO

1 Open the brake.adm file in a text editor.

Adding constraints to the model will involve JOINT/ and MARKER/ statements. Also,

dont forget that the orientation and the location of the I and J markers define the

location and orientation of the joints.

2 Constrain the pedal to the ground.

Save the brake.adm file.

Simulate the model.

Animate the output to ensure this joint is placed correctly.

3 Constrain the connection rod to the pedal.

Save, simulate, and animate again.

4 Constrain the cylinder part to the connection rod.

Save, simulate, and animate again.

5

Constrain the cylinder part to the ground.Save, simulate, and animate again.

When you animate the constrained model, it will not have much movement due to gravity.

Next, you drive the model with a motion.




&KHFNLQJIRUPRYHPHQW

7RFKHFNIRUWKHDSSURSULDWHDPRXQWRIF\OLQGHUPRYHPHQW

1 Use the MOTION/statement to apply a motion to the joint that is between the pedal and the

ground) to move the cylinder at least 30 mm.

To get 30 mm of cylinder movement, you must rotate the pedal about 9o.

For the motion function, use the following equation to represent displacement with

respect to time: STEP(time,0,0,0.1,-9D). Depending on the positive direction in your

model, the last argument -9D may need to be positive in your model.


3 View the animation to check if the brake system is moving properly.




5HTXHVWLQJWKHPRYHPHQW

7RUHTXHVWWKHPRYHPHQWRIWKHF\OLQGHUDQGWKHWRUTXHLQWKHPRWLRQ

1 Request the displacement of the cylinder by entering REQUEST/. Use the I and J markers of

the translational joint between the cylinder and the ground.

2 Request the torque (force) in the motion by entering REQUEST/.

3 Add the REQSAV argument to the OUTPUT/statement that is near the top of the .adm file.


5 Use requests as your source in ADAMS/PostProcessor and plot the displacement through

which the cylinder goes.




6 Use your other request and plot the torque applied to the model by the motion.

$SSUR[LPDWLQJWKHIRUFH

7RDSSUR[LPDWHWKHPD[LPXPIRUFHWKDWQHHGVWREHDSSOLHGWRWKHSHGDO

Approximate the moment arm.

Later, in the next module, you will apply a force to the pedal at a location that is

directly in between markers 1081 and 1082.




To approximate the needed force magnitude, you can divide the torque plot by the

length of the moment arm. First, however, you must calculate the length of the

moment arm.

7 Answer Questions 1 and 2 in the Module review on page 103.

8 Scale the curve:

From the View menu, point to Toolbars, and then select Curve Edit Toolbar.

From the toolbar that appears, select the Scale tool.

Type the reciprocal of the moment arm value in the text box to the right of the Curve

Edit toolbar.

Select Enter.

Left-click the curve you want to scale.

A new curve appears.

You may want to delete the original curve to clean up the view and improve the scale

Answer Question 3 in the Module review on page 103.

(Pedal)PART/10

MAR/1081

MAR/1082

(Connecting Rod)

PART/20

Location?

http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-



2SWLRQDOWDVNV

7RUHPRYHUHGXQGDQWFRQVWUDLQWV

1 By using the .msg file, check to see how many redundant constraints exist in your model.

How many redundant constraints would you need to remove, in order to not have any?

2 Remove the redundant constraints created by two of the joints.

Replace the revolute joint between the pedal and the connecting rod with a spherical

joint.

Replace the translational joint between the cylinder and the ground with a cylindrical

joint.

3 Simulate the model and check for redundancies in the .msg file.




0RGXOHUHYLHZ

1 What are the coordinates of the location exactly in between markers 1081 and 1082?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

2 What is length of the moment arm?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

3 Using the torque measurement, what is the equivalent steady-state force that could be

applied to the pedal?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

4 Does a motion remove DOF?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

5 If you were simulating a complex model and assuming you could get the same

information, would it be quicker to just ask for a request (.req) file or justask for a results(.res) file?

Documents

Adams Solver Guide