MSC ConfidentialPart Number: MDAM*R3*Z*FLEX*Z*SM-ADM710-NT
Copyright 2009 MSC.Software CorporationJuly 2009ADM710 Course
NotesADAMS/FLEXMSC.Software CorporationEuropeMSC.Software GmbHAm
Moosfeld 1381829 Munich, GermanyTelephone: (49) (89) 43 19 87 0Fax:
(49) (89) 43 61 71 6CorporateMSC.Software Corporation2 MacArthur
PlaceSanta Ana, CA 92707 USATelephone: (800) 345-2078Fax: (714)
784-4056Asia PacificMSC.Software Japan Ltd.Shinjuku First West
8F23-7 Nishi Shinjuku1-Chome, Shinjuku-KuTokyo 160-0023,
JAPANTelephone: (81) (3)-6911-1200Fax: (81) (3)-6911-1201MSC
ConfidentialCopyright 2009 MSC.Software Corporation2Legal
InformationMSC.Software Corporation reserves the right to make
changes in specifications and other information contained in
thisdocument without prior notice. The concepts, methods, and
examples presented in this text are for illustrative andeducational
purposes only, and are not intended to be exhaustive or to apply to
any particular engineering problem ordesign. MSC.Software
Corporation assumes no liability or responsibility to any person or
company for direct or indirectdamages resulting from the use of any
information contained herein.Copyright 2009 MSC.Software
Corporation. All Rights Reserved. This notice shall be marked on
any reproduction ofthis documentation, in whole or in part. Any
reproduction or distribution of this document, in whole or in part,
without theprior written consent of MSC.Software Corporation is
prohibited.The MSC.Software corporate logo, Adams, Dytran, Easy5,
Fatigue, Laminate Modeler, Marc, Mentat, MD Nastran, Patran,MSC,
MSC Nastran, Mvision, Patran, SimDesigner, SimEnterprise,
SimManager, SimXpert and Sofy are trademarks orregistered
trademarks of the MSC.Software Corporation in the United States
and/or other countries. NASTRAN is aregistered trademark of NASA.
All other trademarks belong to their respective owners.MSC
ConfidentialCopyright 2009 MSC.Software Corporation3CONTENTSSection
Page0.0 Welcome to Adams/Flex TrainingAbout MSC.Software .....
0-3Course Overview ... 0-4Getting Help .... 0-51.0 Introducing
Adams/FlexVirtual Prototyping Process ..... 1-4How You Benefit from
Using Adams/Flex . 1-8Linear Assumption . 1-12Flexible Body Linear
Limit Check 1-13Controlling Modal Content 1-14Inertia Modeling .
1-19Visualization Attributes . 1-22Workshop 1: Preparing a Can
Crusher Presentation .. WS1-12.0 Theoretical BackgroundModal
Superposition ..... 2-4Craig-Bampton Component Mode Synthesis ...
2-7Mode Shape Orthonormalization . 2-8Kinematics of Markers on
Flexible Bodies . 2-10Applied Forces ... 2-14Flexible Body
Equations of Motion ..... 2-193.0 Replacing Rigid Bodies (Part
I)Renaming Flexible Bodies ....... 3-4Modeling Attributes .......
3-5List Info ........ 3-6Nodes ... 3-7Plotting ........
3-10Workshop 2: Performing a Simple Swap ....... WS2-1MSC
ConfidentialCopyright 2009 MSC.Software Corporation4CONTENTS
(cont.)Section Page4.0 Replacing Rigid Bodies (Part II)About Joints
and Motions ..... 4-4Joints Connection Limitations ...... 4-5About
Dummy Parts ...... 4-7About Forces ...... 4-9Workshop 3: Performing
an Advanced Swap ....... WS3-15.0 Optimizing MNFs and Exporting
LoadsModal Neutral Files .... 5-4Introducing Adams/Flex Toolkit ..
.... 5-5MNF Browser Application ..... 5-6Adams/Flex Toolkit
Optimization Options .. 5-10Command Line Flex Toolkit .
5-25Exporting FEA Loads .... 5-29FEMDATA 5-32Workshop 4: Optimizing
MNFs and Exporting Loads ..... ..... WS4-16.0 Using Flexible Body
StatementsData Transfer ... 6-4Statements Used .... 6-5Matrix Files
...... 6-6Workshop 5: Using External Adams/Solver ...... WS5-17.0
Contacts and Modal ForcesContact with Flexible Bodies . 7-4Modal
Applied Force and Preloaded Flexible Bodies .. 7-6Workshop 6: Using
Contacts and Modal Force ..... ... WS6-1MSC ConfidentialCopyright
2009 MSC.Software Corporation5CONTENTS (cont.)Section Page8.0
Stress Recovery with Adams/DurabilityIntroduction to
Adams/Durability . 8-4Theory of Modal Stress Recovery .. 8-5MSR
Nastran Example 8-13Improving Graphics Performance in
Adams/PostProcessor .. 8-18Using the Hot Spots Table ...
8-23Workshop 7: Stress Recovery with Adams/Durability .........
WS7-19.0 Fatigue AnalysisWhat is Metal Fatigue? ..... 9-4Durability
Design Process .... 9-5Determining Loads .... 9-6Overview of
Fatigue Life Analysis ....... 9-7Stress Life (S-N) Approach ..
9-8Strain Life (E-N) Approach 9-9MSC.Fatigue .. 9-10Workshop 8:
Fatigue Analysis using Adams and Fatigue ........................
WS8-110.0 MNF Generation in NastranModal Neutral Files
10-3Superelement Definition ... 10-4Selecting Attachment Points
10-9What is a Spider Web? .. 10-10ADAMSMNF Case Control ..
10-11Units . 10-16ADMOUT = YES 10-18FLEXONLY = NO .. 10-19Residual
Vectors ....... 10-20Releasing DOF ...... 10-25Common MD DB
10-26MSC ConfidentialCopyright 2009 MSC.Software
Corporation6CONTENTS (cont.)Section Page11.0 Modeling
ConsiderationsFirst Thoughts .... 11-4FE Modeling Considerations
... 11-5Special Adams Modeling Considerations ..... 11-12Concluding
Thoughts .... 11-1512.0 Validating and DebuggingValidating Your
Flexible Body ...... 12-4Workshop 9: Validating and Debugging
........ WS9-113.0 Appendix A Application ExamplesIndustrial Robot
...... A-4Low-Voltage Circuit Breaker .... A-6Flexible Go-Kart
........ A-11Comfort Tire Model ....... A-13Satellite with Flexible
Panels and Antennas ..... A-15Flexible Vehicle Suspension ....
A-17Shell Panels for Missile Separation ........ A-18Landing
Aircraft ...... A-20Flexible Vehicle Frame and Chassis .....
A-22Flexible Car Body in Passing Maneuver .... A-23Pothole Passing
with a Truck ...... A-25Rail Vehicle Comfort Calculations ...
A-3314.0 Appendix B Making an MNF Using FEM SoftwareABAQUS ......
B-4ANSYS ........ B-5I-DEAS ......... B-6Nastran ........ B-7Marc
...... B-10Other MSC Products ...... B-12MSC ConfidentialCopyright
2009 MSC.Software Corporation7CONTENTS (cont.)Section Page15.0
Appendix C Adams/View Command Language SyntaxFlex Body .....
C-4Establish the Selected Modes .. C-5Modifying/Disabling Modes ...
C-6Visualization Attributes ......... C-7Auto-generated Matrix ...
C-8Flex Body Markers ..... C-916.0 Appendix D Adams/Vibration
Frequency Domain AnalysesAdams to Nastran for NVH D-4Nastran Modal
Export for Frequency Domain Stress Recovery . D-5Frequency Response
Function Plots for Stress and Strain . D-617.0 Appendix E Answer
KeyAnswer Key for Workshop 1 .... E-4Answer Key for Workshop 2 ....
E-6Answer Key for Workshop 3 .... E-7Answer Key for Workshop 4 ....
E-9Answer Key for Workshop 5 .... E-14Answer Key for Workshop 6
.... E-17Answer Key for Workshop 9 .... E-18MSC
ConfidentialCopyright 2009 MSC.Software Corporation8S0-1ADM710,
Section 0, July 2008Copyright 2008 MSC.Software CorporationSECTION
0WELCOME TO ADAMS/FLEXTRAININGS0-2ADM710, Section 0, July
2008Copyright 2008 MSC.Software CorporationS0-3ADM710, Section 0,
July 2008Copyright 2008 MSC.Software CorporationABOUT MSC.SOFTWARE
Find a list of MSC.Software products at:
http://www.mscsoftware.com/products/products.cfm Find a list of
Adams products at:
http://www.mscsoftware.com/products/products_detail.cfm?PI=413 Find
additional training at: http://store.mscsoftware.com/training/ Or
your local support center Run through verification problems at:
http://support.mscsoftware.com/kb/results_kb.cfm?S_ID=1-KB9587S0-4ADM710,
Section 0, July 2008Copyright 2008 MSC.Software CorporationCOURSE
OVERVIEW Lecture Hands-on workshops TheoryS0-5ADM710, Section 0,
July 2008Copyright 2008 MSC.Software CorporationGETTING HELP Online
Help To access the Online Help, do either of the following: While
working in any Adams/Flex dialog box, press F1 todisplay Online
Help specific to that dialog box. From the Help menu, select
Adams/View Help. Once the Online Help is displayed, you can browse
throughthe table of contents or the index, or search for any
terms.S0-6ADM710, Section 0, July 2008Copyright 2008 MSC.Software
CorporationGETTING HELP (CONT.)Contents of selected tabTable of
Contents for selected tagIndex/search for entire
Adams/FlexS0-7ADM710, Section 0, July 2008Copyright 2008
MSC.Software CorporationGETTING HELP (CONT.) Technical support To
find your local support center, go to:
http://www.mscsoftware.com/support/contacts/index.cfm To read the
Standard Enhancement & Technical SupportUsage Guide, do one of
the following: If in the United States, go to
http://www.mscsoftware.com/support/Tech_Spt_Guide_Americas.cfm If
outside the United States, go to:
http://www.mscsoftware.com/support/contacts/, and then selectyour
regionS0-8ADM710, Section 0, July 2008Copyright 2008 MSC.Software
CorporationGETTING HELP (CONT.) Knowledge base Go to
http://support.mscsoftware.com/kb Consulting services: Go to
http://www.mscsoftware.com/services/esg/ Adams News and Users
Forums To join the community of Adams users, go to:
http://forums.mscsoftware.com/news/ubbthreads.phpS1-1ADM710,
Section 1, July 2008Copyright 2008 MSC.Software CorporationSECTION
1INTRODUCING ADAMS/FLEXS1-2ADM710, Section 1, July 2008Copyright
2008 MSC.Software CorporationS1-3ADM710, Section 1, July
2008Copyright 2008 MSC.Software CorporationINTRODUCING ADAMS/FLEX
Whats in this section: Virtual Prototyping Process How You Benefit
from Using Adams/Flex Linear Assumption Flexible Body Linear Limit
Check Controlling Modal Content Inertia Modeling Visualization
AttributesS1-4ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationVIRTUAL PROTOTYPING PROCESS Build a model
of your design using: Bodies Forces Contacts Joints Motion
generatorsBuild Test Review ImproveDESIGNPROBLEM Cut time andcosts
Increasequality Increaseefficiency IMPROVEDPRODUCTS1-5ADM710,
Section 1, July 2008Copyright 2008 MSC.Software CorporationVIRTUAL
PROTOTYPING PROCESS (CONT.) Test your design using: Measures
Simulations Animations Plots Validate your model by: Importing test
data Superimposing test dataBuild Test Review ImproveDESIGNPROBLEM
Cut time andcosts Increasequality Increaseefficiency
IMPROVEDPRODUCTS1-6ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationVIRTUAL PROTOTYPING PROCESS (CONT.) Review
your model by adding: Friction Flexible Parts Forcing functions
Control Systems Iterate your design through variations using:
Parametrics Design VariablesBuild Test Review ImproveDESIGNPROBLEM
Cut time andcosts Increasequality Increaseefficiency
IMPROVEDPRODUCTS1-7ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationVIRTUAL PROTOTYPING PROCESS (CONT.) Improve
your design using: DOEs Optimization Automate your design process
using: Custom menus Macros Custom dialog boxesBuild Test Review
ImproveDESIGNPROBLEM Cut time andcosts Increasequality
Increaseefficiency IMPROVEDPRODUCTS1-8ADM710, Section 1, July
2008Copyright 2008 MSC.Software CorporationHOW YOU BENEFIT FROM
USINGADAMS/FLEX Better loading prediction for durability analysis
Improved system performance Additional benefits Adams/Flex provides
valuable insight for the analyst,balancing strength and flexibility
design factors with the costand weight of a mechanism.S1-9ADM710,
Section 1, July 2008Copyright 2008 MSC.Software CorporationHOW YOU
BENEFIT FROM USINGADAMS/FLEX (CONT.) Better loading prediction for
durability analyses The flexible component is the focus of your
attention. What is the system doing to my flexible component?
Examples: Connecting rod Automotive jack standS1-10ADM710, Section
1, July 2008Copyright 2008 MSC.Software CorporationHOW YOU BENEFIT
FROM USINGADAMS/FLEX (CONT.) Improved system performance The model
fidelity is the focus of your attention. Componentflexibility is
just another parameter of the system design. What is the flexible
component doing to my system? Examples: Handling characteristics of
a vehicle with a flexible frame Robot manipulator
pathManipulatorS1-11ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationHOW YOU BENEFIT FROM USINGADAMS/FLEX
(CONT.) Contrasting MSS and FEA Finite element analysis (FEA)
offers excellent modelingcapabilities for individual components in
isolation. Estimatingloads is an art.FEA is too inefficient for
system level modeling and isincapable of analyzing large motion.
Rigid body mechanical system simulation (MSS) efficientlyanalyzes
large motions of complex systems and can be usedto generate
component loads for FEA. However, failure toaccount for component
flexibility can dramatically reducemodeling fidelity. Flexible body
MSS gives you the best of both worlds.S1-12ADM710, Section 1, July
2008Copyright 2008 MSC.Software CorporationLINEAR ASSUMPTION Modal
flexible bodies are linear modeling elements. Deformations are
assumed to be small and within the linearrange. With large
deformations (> 10% of its characteristic length),the
assumptions of modal superposition are violated andresults will be
inaccurate. Sometimes, a flexible body can be deformed beyond
itslinear limit.S1-13ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationFLEXIBLE BODY LINEAR LIMIT CHECK Linear
limit check (C++ Solver Only): Settings > Solver > Flex
Bodies Limit Check Skin: Solver will check the deformation of all
the surface nodes on the skin ofthe flexible body to see whether
they violate the linear limit. Selnod: Solver will only check the
nodes specified in the SELNOD section ofthe mtx file. Limit Action
Halt: Terminates execution of Solver. Return: Stops the simulation
and returns to the command level. Message Only (Default): Only
issues a warning message.S1-14ADM710, Section 1, July 2008Copyright
2008 MSC.Software CorporationCONTROLLING MODAL CONTENT Mode
enabling and disabling Disabling a mode prevents Adams/Flex from
considering thatshape when generating the overall deformed shape of
thecomponent. Manual Table (modal ICs) Range By strain energy
(auto) If a mode does not contribute to the response of the
flexiblecomponent during a simulation, consider disabling it. Your
control over modal degrees of freedom (DOFs) cangreatly affect the
success of your analysis: Too many DOFs can mean unacceptably long
computation time Too few DOFs can prevent Adams from converging to
anacceptable solutionS1-15ADM710, Section 1, July 2008Copyright
2008 MSC.Software CorporationCONTROLLING MODAL CONTENT
(CONT.)S1-16ADM710, Section 1, July 2008Copyright 2008 MSC.Software
CorporationCONTROLLING MODAL CONTENT (CONT.) Modal damping Default:
1% damping for all modes with frequency lower than 100 Hz. 10%
damping for modes with frequency between 100 and 1000Hz. 100%
critical damping for modes with a frequency higher than1000 Hz.
Single scalar damping value applied to all the modes Function
expressions: Damping ratio can be defined by any generic function
expression Two special functions can be used to define the damping
ratio: FXMODE: Returns the mode number of the current mode of
theflexible body FXFREQ: Returns the modal frequency (Hz) of the
current mode ofthe flexible body.S1-17ADM710, Section 1, July
2008Copyright 2008 MSC.Software CorporationCONTROLLING MODAL
CONTENT (CONT.) Example:FLEX_BODY/1CRATIO =
IF(FXFREQ-100:0.01,0.1,if(FXFREQ-1000:0.1,1.0,1.0)) This example
recreates the default modal damping scheme usingnested IF function
expressions. Cycles/user time Control the damping using a DMPSUB
user-writtensubroutine:If you want to specify the modal damping
using morecomplicated expressions, consider a DMPSUB
user-writtensubroutine. For more information, see Knowledge
BaseArticle 9000
at:http://support.mscsoftware.com/kb/results_kb.cfm?S_ID=1-KB9000.S1-18ADM710,
Section 1, July 2008Copyright 2008 MSC.Software
CorporationCONTROLLING MODAL CONTENT (CONT.)S1-19ADM710, Section 1,
July 2008Copyright 2008 MSC.Software CorporationINERTIA MODELING
Inertia modeling There are four preset options and one custom
option: Rigid body - approximates rigid body behavior but
usesflexible body formulation (INVAR6 disabled). Constant -
deformations dont affect the inertial properties. Partial coupling
- the default. Full coupling - uses all nine invariants and,
therefore, is themost computationally intensive choice. Custom -
allows you to set your own or view a preset option,as shown next.
Note that check mark indicates on (or true).S1-20ADM710, Section 1,
July 2008Copyright 2008 MSC.Software CorporationINERTIA MODELING
(CONT.) Preset optionsS1-21ADM710, Section 1, July 2008Copyright
2008 MSC.Software CorporationINERTIA MODELING (CONT.)
CustomS1-22ADM710, Section 1, July 2008Copyright 2008 MSC.Software
CorporationVISUALIZATION ATTRIBUTES Plot type Deformation scale
factor Datum nodeS1-23ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationVISUALIZATION ATTRIBUTES (CONT.) Plot type
Enable color contour or vector plots for a flexible body Options
include: Contour - Sets Adams/Flex so it displays color contour
plots Vector - Sets Adams/Flex so it displays vector plots None -
Displays neither the color contours or vector plots Both - Displays
both the color contours and vector plotsS1-24ADM710, Section 1,
July 2008Copyright 2008 MSC.Software CorporationVISUALIZATION
ATTRIBUTES (CONT.) Deformation scale factor Used to exaggerate
deformation for viewing purposes only Can scale up or down The
deformation scale does not affect the position of markericons
Constraints can appear violated when the scale is >1. This
ismerely visual: the analysis will, of course, maintain
theconstraints youve defined. When the scale is equal to 0, only
the rigid body motion ofthe flexible body will be animated. This
produces fasteranimations for flexible bodies.S1-25ADM710, Section
1, July 2008Copyright 2008 MSC.Software CorporationVISUALIZATION
ATTRIBUTES (CONT.)S1-26ADM710, Section 1, July 2008Copyright 2008
MSC.Software CorporationVISUALIZATION ATTRIBUTES (CONT.) Datum node
Deformation is a relative term and should be expressed withrespect
to a node: You select which node Adams/Flex considers as
theundeformed (datum) node and then color contour plots
revealdeformation relative to it. LBRF (local body reference frame,
the default) is in the samelocation as the reference frame used in
FEA.S1-27ADM710, Section 1, July 2008Copyright 2008 MSC.Software
CorporationVISUALIZATION ATTRIBUTES (CONT.)S1-28ADM710, Section 1,
July 2008Copyright 2008 MSC.Software CorporationVISUALIZATION
ATTRIBUTES (CONT.) Example of using different datum nodes Here,
node 1000 is the datum node. In this case, node 1001 is the datum
node. The color red denotes maximum deformation relative to
thedatum node.Node 1000 Node 1001Node 1000 Node 1001WS1-1ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1PREPARING A
CAN-CRUSHERPRESENTATIONWS1-2ADM710, Workshop 1, July 2008Copyright
2008 MSC.Software CorporationWS1-3ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 PREPARING A
CAN-CRUSHERPRESENTATION Problem statement You have just been
promoted to a high-profile project. Yoursupervisor is responsible
for the dynamic analysis of a can-crushing mechanism. He wants you
to prepare apresentation that includes: Table of eigenvalues from
Adams/Linear Screen snapshot (.jpg) of system mode 8 A plot of the
y-component of the torque in a revolute jointversus the distance
the can has been compressed Animation movie files (.avi) of the
flexible body model alongsidethe rigid body model A Web page with
the presentation. For example:WS1-4ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.)WS1-5ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)
Mechanism information This model represents a can-crushing
mechanism, as shownin Figure 1:CanBaseCouplerPlungerNode 2505Node
2502Node 2498flx_leverWS1-6ADM710, Workshop 1, July 2008Copyright
2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) The mechanism includes the following
parts:WS1-7ADM710, Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) An input
force is applied to the end of FLX_LEVER with aSTEP function and
turns off after 0.55 seconds.ForceWS1-8ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) Setting up the model To set up the model:1.
Start Adams/View from the
directoryexercise_dir/mod_01_cancrusher.Where exercise_dir is the
directory where the workshopsubdirectories reside.2. From the same
directory, import the model command
filecancrusher_start.cmd.ADAMS/View displays the model named
cancrusher. Inspecting the flexible lever You can quickly inspect
the flexible lever to see how each modewould contribute to its
deformation.WS1-9ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)
To inspect the flexible lever:1. From the Main Toolbox, select the
Isometric tool , and then selectRender.2. Turn off icon (v) and
grid visibility (g). You can turn on and off the iconand grid
visibility as needed throughout the course.3. If the strip chart is
blocking the view, you can move it aside.4. Right-click FLX_LEVER,
point to Flexible_Body: FLX_LEVER, andthen select Modify.5. In the
Mode Number text box, enter 10, and then press Enter.ADAMS/View
displays mode 10 superimposed on the undeformedbody:Mode
10WS1-10ADM710, Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)6. In the
Flexible Body Modify dialog box, select the Animate tool
.Adams/View animates mode 10 for three cycles.7. To see how
Adams/View displays the deformation mode and theundeformed body,
toggle the Superimpose option a few times.8. Set Plot Type to
Contour.The resulting contours show deformation, not stress.9. To
exaggerate the results, set Deformation Scale Factor to 2.0,
andthen press Enter.WS1-11ADM710, Workshop 1, July 2008Copyright
2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.)10. Animate mode 10 once again and note the
difference caused by theincreased deformation scale factor.11.
Review modes 7 - 28. The first six modes are rigid body modes
andare automatically disabled because Adams/Flex already handles
thedynamics for those modal degrees of freedom.12. Set Deformation
Scale Factor back to 1.0.WS1-12ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) Simulating the rigid lever Make the lever
temporarily rigid, and then simulate it to observethe can-crushing
operation. To simulate the rigid lever:1. Set Inertia modeling to
Rigid body.2. Select OK.3. Confirm that the flexible body is not
selected. From the Main Toolbox,select the Select tool to clear the
Select List. You should do thiswhenever you want to stop seeing the
model in a dimmedappearance.4. From the Simulate menu, select
Scripted Controls.WS1-13ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.)5. Run scripted simulation using the script
.cancrusher.RIGID_SCRIPT.The script uses the following Adams/Solver
commands:SIM/STATICSINTEGRATOR/GSTIFF, HMAX=.01SIM/TRANSIENT,
END=0.75, STEPS=50The strip chart CAN_COMPRESSION_MEA displays the
deformationof the can versus time.WS1-14ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.)6. From the Simulation Control dialog box,
select the Save SimulationResults tool .7. Save the results with
the name rigid. You will use these results laterin your
presentation material.8. Animate the results of the simulation.The
lever arm stays blue because its not deforming. It is notdeforming
because you set Inertia Modeling to Rigid Body.9. Close the
Animation Controls dialog box or reset the model to themodeling
view by other means.WS1-15ADM710, Workshop 1, July 2008Copyright
2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) Simulating the flexible lever Make the lever
flexible again, and then simulate it to observe itsmotion. To
simulate the flexible lever:1. Right-click FLX_LEVER, point to
Flexible_Body: FLX_LEVER, andthen select Modify.2. In the Flexible
Body Modify dialog box, set Damping Ratio todefault.Deformations of
the flexible body are displayed relative to the datumnode. You'll
choose node 2505 because it is at the opposite end of theapplied
load, as shown in Figure 1. The colors indicate the magnitudeof the
deformation: red indicates the most deformation, blue the least.2.
Clear the selection of LBRF.3. In the Datum Node text box, enter
2505.4. Set Inertia modeling to Partial coupling.Partial coupling
is the default flexible body representation of the
inertiainvariants.5. Select OK.6. Clear the selection of the
lever.WS1-16ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.)7. Perform another scripted simulation
using.cancrusher.FLEX_SCRIPT.The script uses the following
Adams/Solver commands:SIM/STATICSLINEAR/EIGENSOLINTEGRATOR/GSTIFF,
SI2, HMAX=0.01SIM/TRANSIENT, END=0.75, STEPS=508. Save the
simulation results as flexible.9. Animate the results of the
simulation.By animating the results you've seen how the flexible
lever deforms asthe load is applied. You may have noticed in the
script that anAdams/Linear eigenvalue solution was performed at the
static position.In the next section you will learn how to export a
table of eigenvaluesand create an image of one of the eigenmodes
which will be used inyour presentation.WS1-17ADM710, Workshop 1,
July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 1
CAN-CRUSHER PRESENTATION(CONT.) Preparing the eigenvalue data table
For your presentation, generate a table of system eigenvaluesfrom
Adams/Linear and export it to a text file. To prepare the data
table:1. From the Review menu, select Postprocessing or press the
F8 key.2. Right-click the viewport, and then select Load Mode
ShapeAnimation.3. From the Database Navigator, under flexible,
double-click the Eigenresults (for example,
EIG_1).Adams/PostProcessor displays the model and updates the
dashboardwith mode shape animation controls.4. From the dashboard,
select Table of Eigenvalues.The Information window displays the
table.5. Select Save to File, and save the file as
system_modes.txt.6. Close the Information window.WS1-18ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) Creating an
image of the lever For your presentation, create a color image of
system mode8 and name it mode_8.jpg.Figure 2. System Mode
8WS1-19ADM710, Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) To create the
image:1. To display the triad, from the dashboard, select the View
tab, andthen select Display Triad.2. For optimal viewing, fit the
model in the viewport by using the viewcontrol keyboard shortcuts,
rotate, zoom, and translate so that youhave a view of the model
similar to the view in Figure 2.3. From the dashboard, select the
Mode Shape Animation tab.4. Set Mode Number to 8, to display mode 8
and its frequency. Note itsfrequency: _____(hz).5. Change the Scale
Factor to 0.1.6. To animate mode 8, select the Play tool
.WS1-20ADM710, Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)7. Observe the
mode shape animation, and when youve finishedanimating, press the
Pause tool .Why do you think that mode 8 is
important?________________________________________________________________________________________________________________________________________________________________________8.
Select the Reset tool .9. From the File menu, select Print.10. Set
Print to File.11. In the File Name text box, enter mode_8.jpg.12.
Set the pull-down menu, directly under File Name, to JPG.13. Select
OK.Adams/PostProcessor creates the image file.WS1-21ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) Comparing
animations You use Adams/PostProcessor to compare the animationsof
the rigid and the flexible levers. You compare animationsusing the
overlay feature.Figure 3 shows how your window looks after
youvecompleted the steps in this section.WS1-22ADM710, Workshop 1,
July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 1
CAN-CRUSHER PRESENTATION(CONT.)Figure 3. Overlaying Animation
ResultsWS1-23ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)
To compare animations:1. Delete the current page to remove the mode
shape animation.2. From Adams/PostProcessors Main toolbar, from the
Page layouttool stack, select the 2 Views, side by side tool .3.
Right-click the viewport on the right, and then select Load
Animation.4. Double-click rigid.5. For optimal viewing, fit the
model in the viewport.6. As shown in Figure 3, overlay the
simulation named flexible: From the dashboard, select the Overlay
tab. In the Offset text box, enter -10, 0, 0. In the Colors text
box, enter blue. Hold down the Control key and multiple-select
.cancrusher.rigid and.cancrusher.flexible. Move the pointer out of
the dashboard area, to execute the command(which can take a
while).7. Fit the models in the viewport and then animate by
selecting the Playtool.8. After you finish viewing the animation,
pause it.WS1-24ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)
Observing deformations Deformations of the flexible body are
displayed relative to thedatum node you assigned earlier, in
Simulating the flexible lever.Increase the deformation scale so
that you can better visualize thedeformation in the movie file you
will be creating soon. To exaggerate deformations:1. Right-click
the flexible body, point to Flexible_Body: FLX_LEVER,and then
select Select.2. In the Flex Props tab, set Scale to 20, and then
press Enter.3. To clear the selection of the flexible body, select
the Select tool .4. Animate again.Notice how increasing the scale
factor has exaggerated the flexiblelever deformations.WS1-25ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.)WS1-26ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) Comparing
joint torque plots As the lever crushes the can, you can see the
combinedtwisting and bending of the lever. The twisting and
bendingproduces force components that act as a torsional load onthe
revolute joint (at the coupler). The torque climbs until thecan
finally collapses from the crushing operation. At the endof the
duty cycle, the load in the lever is relieved and thejoint torque
drops back to zero. The measure for the jointtorque is named
LVR_CPLR_REV_MEA_TY and you willplot it versus the deformation of
the can,CAN_COMPRESSION_MEA.WS1-27ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) To compare plots:1. Right-click the viewport on
the left and select Load Plot. If an alert boxappears, select OK to
dismiss it.2. In the dashboard, set Source to Measures.3. Set
Independent Axis to Data, and then selectCAN_COMPRESSION_MEA as the
independent data measure.4. Select Surf. The Surf feature lets you
quickly browse or surf throughmultiple results. Using it can
eliminate mouse clicks and otheroperations, such as delete, undo,
and so on.5. Select both the rigid and the flexible analyses, and
plotLVR_CPLR_REV_MEA_TY.6. If the legend obscures the plot, select
it and move it up slightly.7. Clear the selection of the legend.8.
Select the viewport on the right, and then animate.WS1-28ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) Preparing the
movie file To prepare the movie file:1. Click on the viewport on
the right.2. From the dashboard, select the Animation tab.3. Choose
a frame range of 1 to 50, and then press Enter.4. Reset the
animation so it displays the first frame.5. For optimal viewing,
fit the models in the viewport.6. To prepare for recording the .avi
file, select the Record tab.7. Clear the File Name text box.8. In
the File Name text box, enter the name movie.9. Verify that Format
is set to AVI.10. Select the Record tool.11. Select Play.Note: Do
not change windows during the record phase.12. After the animation
goes through one pass, or 50 frames, select Pause.Note: Do not
return to Adams/View because you will complete the nextsteps in
Adams/PostProcessor.WS1-29ADM710, Workshop 1, July 2008Copyright
2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) Publishing to the Web For publishing to the
Web, you export data in the currentsession of Adams/PostProcessor
as HTML pages forviewing by others in your
organization.Adams/PostProcessor also creates: Plots and animations
as .png, .jpg, .bmp, .xpm, or .tiff images. Movies of animations as
.avi or .mpg. Information about the parts, constraints, forces, and
more inthe selected models. This is the same information that
appearswhen you select Info.WS1-30ADM710, Workshop 1, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.) To publish to the Web:1. From the treeview in
Adams/PostProcessor, select page_1.2. From the Edit menu, select
Rename, and then rename the page to movie.3. From the main toolbar,
select the Create a new page tool .4. Rename this page to
system_modes.5. From the Page Layout tool stack , select the 1 View
tool .6. Right-click the viewport, and then select Load Report.7.
Double-click system_modes.txt.8. From the main toolbar, select the
Create a new page tool.9. Rename this page to can_compression.10.
Right-click the viewport, and then select Load Plot.11. Set Source
to Measures.12. Plot the CAN_COMPRESSION_MEA for both the rigid and
flexible bodies.WS1-31ADM710, Workshop 1, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 1 CAN-CRUSHER
PRESENTATION(CONT.)13. From the File menu, point to Export, and
then select HTML Report.14. Select OK.Note: Do not change windows
because the movie will be re-recorded.Adams/PostProcessor creates a
folder, named html_export, in yourworking directory.15. From the
Adams/PostProcessor Main toolbar, select to return to themodeling
environment.16. Save the database using the default name.17. Exit
Adams/View.18. Open the html_export folder.19. In a browser, open
index.html.20. To view the results, expand the pages folder.21.
Expand the cancrusher folder to browse information on the
parts,constraints, and forces in the selected model.WS1-32ADM710,
Workshop 1, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 1 CAN-CRUSHER PRESENTATION(CONT.) Module
review1. How does the system mode 8 compare with the flexiblebody
mode that is near the same
frequency?________________________________________________________________________________________________________________________________________________2.
Can you suggest a better reference frame in which toexpress the
measure
LVR_CPLR_REV_MEA_TY?________________________________________________________________________________________________________________________________________________S2-1ADM710,
Section 2, July 2008Copyright 2008 MSC.Software CorporationSECTION
2THEORETICAL BACKGROUNDS2-2ADM710, Section 2, July 2008Copyright
2008 MSC.Software CorporationS2-3ADM710, Section 2, July
2008Copyright 2008 MSC.Software CorporationTHEORETICAL BACKGROUND
Whats in this section: Modal superposition Craig-Bampton Component
Mode Synthesis Mode Shape Orthonormalization Kinematics of Markers
on Flexible Bodies Applied Forces Flexible Body Equations of
MotionS2-4ADM710, Section 2, July 2008Copyright 2008 MSC.Software
CorporationMODAL SUPERPOSITION Represent deformation as a linear
combination ofmode shapes Simple example Craig-Bampton modes
distinguishes boundary nodesfrom interior nodesS2-5ADM710, Section
2, July 2008Copyright 2008 MSC.Software CorporationMODAL
SUPERPOSITION (CONT.) Fixed boundary normal modes Obtained by
fixing the boundary DOF and computing aneigensolution. There are as
many fixed-boundary normalmodes as the user desires. These modes
define the modalexpansion of the interior DOF. The quality of this
modalexpansion is proportional to the number of modes retainedby
the user. Two fixed-boundary normal modes for a beam that
hasattachment points at the two ends.S2-6ADM710, Section 2, July
2008Copyright 2008 MSC.Software CorporationMODAL SUPERPOSITION
(CONT.) Constraint modes Static shapes obtained by giving each
boundary DOF a unitdisplacement while holding all other boundary
DOF fixed. Thebasis of constraint modes completely spans all
possiblemotions of the boundary DOFs, with a
one-to-onecorrespondence between the modal coordinates of
theconstraint modes and the displacement in the
correspondingboundary DOF. Two constraint modes for the left end of
a beam that hasattachment points at the two ends. The figure on the
leftshows the constraint mode corresponding to a unit
translation.The figure on the right corresponds to a unit
rotation.S2-7ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationCRAIG-BAMPTON COMPONENT MODESYNTHESIS
Deformations are represented in Craig-Bamptonmodal basis Transform
stiffness and mass matrices to Craig-Bampton basis Generalized
stiffness Generalized massS2-8ADM710, Section 2, July 2008Copyright
2008 MSC.Software CorporationMODE SHAPE ORTHONORMALIZATION Problems
using raw Craig-Bampton modes Constraint modes embed rigid body
motion. Constraint modes do not advertise the
high-frequencydynamics that they add Constraint modes cannot be
disabled in Adams Solve a second eigenvalue problem Eigenvalue
problem yields coordinate transformation Transformation
orthonormalizes modesS2-9ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationMODE SHAPE ORTHONORMALIZATION(CONT.)
Physical interpretation of orthonormalized modes Approximate free
body modes Boundary eigenvectors Before: After: Problem solved
Rigid body modes drop out All modes have natural frequency
Disabling high-frequency boundary eigenvectors is
benignS2-10ADM710, Section 2, July 2008Copyright 2008 MSC.Software
CorporationKINEMATICS OF MARKERS ON FLEXIBLEBODIES Why are marker
kinematics needed? Joints Generalized forces Expressions Position
Velocity OrientationS2-11ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationKINEMATICS OF MARKERS ON FLEXIBLEBODIES
(CONT.) Position Use slice of modal matrix corresponding to
translations of P Generalized coordinatesS2-12ADM710, Section 2,
July 2008Copyright 2008 MSC.Software CorporationKINEMATICS OF
MARKERS ON FLEXIBLEBODIES (CONT.) Velocity Differentiate position
with respect to time Simplify using the relationship further
simplify whereS2-13ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationKINEMATICS OF MARKERS ON FLEXIBLEBODIES
(CONT.) Orientation Use slice of modal matrix corresponding to
rotations of P Orientation of marker at P is the product of three
Eulertransformation matrices Reorientation due to deformation
builds on the small rotationassumptionS2-14ADM710, Section 2, July
2008Copyright 2008 MSC.Software CorporationAPPLIED FORCES Point
forces and torques Distributed loads Residual forces and residual
vectors PreloadsS2-15ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationAPPLIED FORCES (CONT.) Point forces and
torques Generalized forces Generalized force on the translations
Generalized torque on the Euler angles Generalized modal
loadS2-16ADM710, Section 2, July 2008Copyright 2008 MSC.Software
Corporation Distributed loads New Adams element, the MFORCE FEM
equation of motion Transform to modal coordinates Modal load Assume
that time varying load may be represented as a timevarying linear
combination of static load cases Pre-project the static load cases
on the modes In Adams, scale factors can be a function of time and
stateAPPLIED FORCES (CONT.)S2-17ADM710, Section 2, July
2008Copyright 2008 MSC.Software CorporationAPPLIED FORCES (CONT.)
Residual forces and residual vectors When load is projected on the
modes, not all the load maymake it The residual forcegives us an
additional mode (the residual vector) whichenhances the
Craig-Bampton basis.S2-18ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationAPPLIED FORCES (CONT.) Preloads An Adams
flexible body can contain a preload. This allowsAdams to support
flexible bodies linearized in a non-linearlydeformed
state.S2-19ADM710, Section 2, July 2008Copyright 2008 MSC.Software
CorporationFLEXIBLE BODY EQUATIONS OF MOTION Lagrange's
equationS2-20ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationFLEXIBLE BODY EQUATIONS OF MOTION(CONT.)
Mass matrix Velocity represented as a product of a matrix and the
timederivative of the state vector Kinetic energy The flexible body
mass matrix. We study it in block formS2-21ADM710, Section 2, July
2008Copyright 2008 MSC.Software CorporationFLEXIBLE BODY EQUATIONS
OF MOTION(CONT.) The blocks are conveniently represented as
products ofinertia invariantsS2-22ADM710, Section 2, July
2008Copyright 2008 MSC.Software CorporationFLEXIBLE BODY EQUATIONS
OF MOTION(CONT.)where the invariants are computed in a
preprocessorS2-23ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationFLEXIBLE BODY EQUATIONS OF MOTION(CONT.)
Gravity and stiffness Potential energy includes stiffness effects
and gravity The stiffness matrix is very simple because it has no
rigidbody contribution Generalized forces due to
gravityS2-24ADM710, Section 2, July 2008Copyright 2008 MSC.Software
CorporationFLEXIBLE BODY EQUATIONS OF MOTION(CONT.) Damping Damping
is assumed to be derivable from a quadratic form The equation of a
simple harmonic oscillatorleads to a characteristic
equationS2-25ADM710, Section 2, July 2008Copyright 2008
MSC.Software CorporationFLEXIBLE BODY EQUATIONS OF
MOTION(CONT.)which yields the eigenvalues Critical damping occurs
when the harmonic term vanishes Modal damping in Adams is
represented as a fraction ofcritical dampingS2-26ADM710, Section 2,
July 2008Copyright 2008 MSC.Software CorporationFLEXIBLE BODY
EQUATIONS OF MOTION(CONT.) Equations of motionfinal form The final
form of the equation of motionS3-1ADM710, Section 3, July
2008Copyright 2008 MSC.Software CorporationSECTION 3REPLACING RIGID
BODIES (PART I)S3-2ADM710, Section 3, July 2008Copyright 2008
MSC.Software CorporationS3-3ADM710, Section 3, July 2008Copyright
2008 MSC.Software CorporationREPLACING RIGID BODIES (PART I) Whats
in this section: Renaming Flexible Bodies Modeling Attributes List
Info Nodes PlottingS3-4ADM710, Section 3, July 2008Copyright 2008
MSC.Software CorporationRENAMING FLEXIBLE BODIES Uses the same
method as rigid bodies When you rename a flexible body: Adams/View
writes a new matrix (.mtx) file when you issuethe next simulation
command or export an .adm file The original matrix file is now
redundant and since you dontneed it, you may delete it Adams/View
creates a redundant matrix file when you exportthe dataset (.adm).
The .adm uses this new matrix file. Keep in mind that matrix names
do not update until the nexttime you solve or export a
datasetS3-5ADM710, Section 3, July 2008Copyright 2008 MSC.Software
CorporationMODELING ATTRIBUTES Color Use the same method as you
would for rigid bodies Doesnt affect deformation colors
Active/inactive Use the same method as you would for rigid
bodiesS3-6ADM710, Section 3, July 2008Copyright 2008 MSC.Software
CorporationLIST INFO Use it to view flexible body parameters We
suggest using the Verbose option because itincludes the mode
enabled/disabled statusS3-7ADM710, Section 3, July 2008Copyright
2008 MSC.Software CorporationNODES The following options are
available for locating markers on flexiblebodies:1. Coincident to a
node Default option Compatible with Adams/Solver (FORTRAN)2. Offset
from a node Must first create the marker at a node, then modify it
to the desired offsetdistance Adams/Flex will apply forces to the
node Compatible with Adams/Solver (C++) Adams/Solver (FORTRAN)
automatically adds an interface part3. Attached to multiple nodes
Must first create the marker attached to one node, then modify the
marker toattach it to multiple nodes Allows the user to distribute
loads to multiple nodes to avoid unrealistic stressconcentrations.
Compatible with Adams/Solver (C++) ONLY Adams/Solver (FORTRAN) does
not support this optionNote: Option 1 is the only option available
before MSC.ADAMS 2003.S3-8ADM710, Section 3, July 2008Copyright
2008 MSC.Software CorporationNODES (CONT.) Nodes are shown on mesh
You can pick nodes based on FEM ID in the
modelingenvironmentS3-9ADM710, Section 3, July 2008Copyright 2008
MSC.Software CorporationNODES (CONT.) Joints and forces may be
applied at any location on a flexiblebody. The applied forces or
reaction forces, however, will onlybe applied at node locations.
For markers that are attached to one node with no offset, the
forcewill be applied directly to that node. For markers that are
attached to one node with an offset, the forcewill be transferred
to the node and applied to the flexible body atthis nodes location.
This behavior is similar to creating a massless-rigid link between
the marker (where the force is located) and thenode (where the
force is being applied to the flexible body). For markers that are
attached to multiple nodes, the weighted forceis transferred to
each node and then applied to the flexible body atthe node
locations.For more information, in the online help for Adams/Solver
(C++),follow the link: Statements Marker. Measures may reference
any marker on a flexible body. You can designate any single node as
a datum node fordeformation color contours.S3-10ADM710, Section 3,
July 2008Copyright 2008 MSC.Software CorporationPLOTTING Result set
components Standard measures User-written measures Output
requestsS3-11ADM710, Section 3, July 2008Copyright 2008
MSC.Software CorporationPLOTTING (CONT.) Result set components You
can plot the modal displacements and their derivatives(Q, DQ,
DDQ)S3-12ADM710, Section 3, July 2008Copyright 2008 MSC.Software
CorporationPLOTTING (CONT.) Standard measures Available object
characteristics: Center of mass (CM) position CM velocity
(translational and angular) CM acceleration (translational and
angular) Potential energy delta Kinetic energy (total, angular, and
translational) Strain energy (due to deformation) Momentum
(translational and angular) CM position relative to LBRF Available
results data: Modal coordinates, velocities, and accelerations Part
displacements, velocities, and accelerations (just likerigid
bodies)S3-13ADM710, Section 3, July 2008Copyright 2008 MSC.Software
CorporationPLOTTING (CONT.)S3-14ADM710, Section 3, July
2008Copyright 2008 MSC.Software CorporationPLOTTING (CONT.)
User-written measures Point-to-point measures Object measures
Markers on flexible bodies also support all standard markermeasures
and additional deformation measures (relative toLBRF).S3-15ADM710,
Section 3, July 2008Copyright 2008 MSC.Software CorporationPLOTTING
(CONT.)Point-to-point measures Object measuresAdams/PostProcessor
dashboardS3-16ADM710, Section 3, July 2008Copyright 2008
MSC.Software CorporationPLOTTING (CONT.) Output requests Define
using type and markers Displacement, velocity, acceleration, and
force Define using subroutine (REQSUB) Define using function
expressionYou can create output requests by using markers on
theflexible body.Limitation: Because there is no center of mass
(cm) marker fora flexible body, you cannot make a request from a
cmmarker.WS2-1ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2PERFORMING A SIMPLE
SWAPWS2-2ADM710, Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWS2-3ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP Problem
statement The design team is concerned about how
componentflexibility may influence the system performance of a
robot.You need to modify the rigid-body model so it contains
aflexible part, and then investigate the effects of that change.
Mechanism information The model represents a robotic welding
mechanism, asshown below:HandWrist ForearmArm
LevelShoulderBaseFigure 4. Robotic Welding MechanismWS2-4ADM710,
Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.) The following
table lists the robotic welding mechanism parts, theirassociated
geometry, and characteristics. Note that the dummy parts listed in
the table only exist for graphicalreasons. They could be easily
deleted from the model withoutaffecting the functionality. Deleting
these parts would decrease thenumber of equations in Adams/Solver,
therefore, solving moreefficiently.WS2-5ADM710, Workshop 2, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 2 PERFORMING A
SIMPLE SWAP(CONT.) The following table lists the robotic welding
mechanismjoints, their type, and associated input motions. The
motionsare applied to the joints and control the
angulardisplacements for the operational sequence.WS2-6ADM710,
Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)WS2-7ADM710,
Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.) Setting up
the model To set up the model:1. Run ADAMS/View from the directory
exercise_dir/mod_03_robot.2. From the same directory, import the
model command filerobot_rigid_start.cmd.3. Adams/View displays the
model named robot.4. Set the render mode to shaded (type an
uppercase S).5. Turn off icon and grid visibility.WS2-8ADM710,
Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.) Simulating
the model Before you simulate the model, set the specifications for
the analysisfiles that Adams/View outputs. You may want to use
these files laterto compare the rigid analysis with the flexible
one. To simulate the model:1. From the Settings menu, point to
Solver, and then select Output.2. Set Save Files to Yes.3. In the
File Prefix text box, enter robot_rigid.4. Close the Solver
Settings dialog box.5. Run a scripted simulation using
.robot.RIGID_SCRIPT.The script uses the following Adams/Solver
commands:SIM/STATICSKINEMATIC/ERROR = 1e - 4SIMULATE/KINEMATIC,
DURATION=1.7, DTOUT=1.0E-02WS2-9ADM710, Workshop 2, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 2 PERFORMING A
SIMPLE SWAP(CONT.)6. Animate the results.7. Save the simulation
results as rigid.8. To return to the model view, from the View
menu, select Model. Swapping in the flexible forearm You now import
a flexible forearm. You use the rigid-to-flex utility toreplace the
rigid forearm with a flexible one. To import the flexible
forearm:1. From the Build menu, point to Flexible Bodies, and then
select Rigidto Flex.2. Right-click the Current Part text box, point
to Part, point to Browse,and then select the part
FOREARM.WS2-10ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE
SWAP(CONT.)3. Right-click the MNF File text box, point to Browse,
and then selectrobot_arm_easy.mnf.4. Set Flex Body Positioning to
Align Flex Body CM with CM ofCurrent Part.Note: Do not select Apply
or OK yet.The dialog box should look as follows:Flexible BodyRigid
BodyWS2-11ADM710, Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)The model now
includes the flexible forearm, as shown next:WS2-12ADM710, Workshop
2, July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 2
PERFORMING A SIMPLE SWAP(CONT.) Establishing flex body connections
To establish connections:1. Select the Connections tab.2. Hold down
the Ctrl key and select the rows for MK13 and MK14.3. Select
Preserve location.The dialog box should look as follows:4. Select
Apply or OK.WS2-13ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)
Switching to Adams/Solver (C++) To switch to Adams/Solver (C++):1.
From the Settings menu, point to Solver, and then
selectExecutable.2. Set Choice to C++.3. Close the Solver Settings
dialog box.4. From the Tools menu, select Model Verify, and then
check thatyouve established the correct connections and the model
is ready torun.5. Close the Information window.6. Before
continuing, save the model in binary format.WS2-14ADM710, Workshop
2, July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 2
PERFORMING A SIMPLE SWAP(CONT.) Preparing the flexible forearm To
prepare the flexible forearm for analysis, you set parameters
forinertia, disable modes that we dont want to include in this
analysis,and set deformation display parameters. To prepare the
flexible forearm:1. In the Flexible Body Modify dialog box, verify
that Inertia modelingis set to Partial coupling.2. In the Mode
Number text box, enter 12.3. Select Disable .4. In the Mode Number
text box, enter 16.5. Select Disable.6. Clear the selection of LBRF
and make node 3000 the datum node.7. Ensure that Plot Type is set
to Contour.8. Select Apply or OK.9. Clear the selection of the
forearm.WS2-15ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)
Building a measure You build a measure of the lateral deflection of
the flexible forearm.Later, you will use the measure to see how
much the forearmdeforms as the robot moves through its prescribed
path. To build a measure:1. From the Build menu, point to Measure,
point to Point-to-Point,select New, and then use the following
specifications: Create Strip Chart: clear its selection (uncheck)
Measure Name: FOREARM_LATERAL_DEFL To Point: ARM_PIN.MK21 From
Point: WRIST_PIN.MK23 Characteristic: Translational displacement
Component: Z Represent coords in: ARM_PIN.MK212. Select
OK.WS2-16ADM710, Workshop 2, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.) Simulating
the flexible forearm To simulate the flexible forearm:1. From the
Simulate menu, point to Simulation Script, and then selectNew.2. In
the Script text box, enter .robot.FLEX_SCRIPT.3. Set Script Type to
Adams/Solver Commands.4. In the Adams/Solver Commands text area,
enter:SIM/STATICSINTEGRATOR/SI2, GSTIFF,
HMAX=1E-3SIMULATE/TRANSIENT, DURATION=1.7, DTOUT=1.0E-025. Select
OK.6. Set simulation settings to Save Files, and assign it the file
prefixrobot_module3.Tip: See Step 1 - Step 4 under Simulating the
model.WS2-17ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE
SWAP(CONT.)7. Perform a simulation using FLEX_SCRIPT.As the
simulation runs, the screen updates with the robot motion.
Thedeformation contours represent the relative deformations for the
givenanimation frame.8. To see how much the flexible forearm has
deflected laterally (or end toend), display the strip chart for the
measure you created earlier inBuilding a measure: from the Build
menu, point to Measure, selectDisplay, and then double-click
FOREARM_LATERAL_DEFL.9. Save the last simulation results as flex
(in the Simulation Controldialog box, select ) .10. From the Main
Toolbox, animate the model with the Loop and theContour Plots
options selected.WS2-18ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)
Inspecting the results To inspect the results:1. Launch
Adams/PostProcessor.2. Display a horizontal, 2-page layout ( ).3.
In the upper viewport, for the flexible run, plot the
measureFOREARM_LATERAL_DEFL versus time.4. In the lower viewport,
load the animation of the analysis.5. Choose HAND.TIP as the trace
marker.Tip: To see this marker in your model, turn on the
visibility of icons.Hand TipWS2-19ADM710, Workshop 2, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 2 PERFORMING A
SIMPLE SWAP(CONT.)6. Animate the model.7. Rotate the model so you
can see the trace from different perspectives.8. To see the hand
tip vibrate as it momentarily comes to rest, zoom inon the part of
the trace where the plot shows the vibration at the firstdwell
point.Note: If you're having trouble seeing the trace because its
obscuredby the HAND.CYLINDER geometry, you can set its transparency
to 25or remove its endcap. To remove the endcap: from the Edit
menu,point to Preferences, and then clear the selection of
GraphicsEndcaps, which is located under the Geometry tab.9. Return
to Adams/View.10. Save the model as robot.bin.Now you've learned
how to run flexible body simulations with theintegrated solver in
Adams/View.WS2-20ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)
Exporting the model An easy way to export all model files in a
single operation is to use a scriptmode known as Write Files Only.
This is a good way to archive your .admand .acf files for future
reference. Exporting the model in this way givesyou the minimal
file set required to re-run the simulation with
stand-aloneAdams/Solver. To export the model:1. From the Settings
menu, point to Solver, and then select Executable.2. Set Executable
to Write Files Only.3. Close the dialog box.4. Run another scripted
simulation using FLEX_SCRIPT. This will finish veryquickly because
it doesnt really run a simulation: it only wrote the files.5. Check
that ADAMS/View wrote the following files to your disk:
robot_module3.acf robot_module3.adm
robot_module3_FOREARM_flex.mtx7. You will use these files again in
Workshop 5 Using External Adams/Solver. Exit
Adams/View.WS2-21ADM710, Workshop 2, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 2 PERFORMING A SIMPLE SWAP(CONT.)
Optional tasks1. Use xdiff (or equivalent) to compare your dataset
with the one inthe directory completed/robot_module3.adm. Do the
differencesmake sense?_______Yes _______No.Consider discussing the
differences that you cannot explain.2. To see the effect of the MNF
path by inspecting the file robot.bin: Rename the working directory
of this module: change it frommod_03_robot to mod_03_robot_renamed.
Start Adams/View in mod_03_robot_renamed and open thedatabase,
robot.bin. Is the flexible body in the model? _______Yes _______No.
Whatprevents it from being
displayed?______________________________________________________ To
fix the display problem: Tools Command Navigator part modify
flexible_body name_and_position. Browse for the flexible body and
then fix the path for Modal Neutral FileName.WS2-22ADM710, Workshop
2, July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 2
PERFORMING A SIMPLE SWAP(CONT.) Module review The motions in this
module used STEP5 functions. This plotshows a comparison of the
rigid forearm acceleration usingSTEP and STEP5 functionslist some
reasons why STEP5is preferable in this
application.________________________________________________________________________________________________________________________________________________________________________________________________S4-1ADM710,
Section 4, July 2008Copyright 2008 MSC.Software CorporationSECTION
4REPLACING RIGID BODIES (PART II)S4-2ADM710, Section 4, July
2008Copyright 2008 MSC.Software CorporationS4-3ADM710, Section 4,
July 2008Copyright 2008 MSC.Software CorporationREPLACING RIGID
BODIES (PART II) Whats in this section: About Joints and Motions
Joint Connection Limitations About Dummy Parts About
ForcesS4-4ADM710, Section 4, July 2008Copyright 2008 MSC.Software
CorporationABOUT JOINTS AND MOTIONS Using joints After you bring a
flexible body into Adams/View, you canconnect it to your rigid
model using the Adams/View libraryof constraints. Joint locations
Joints attached to a flexible body must originally be locatedat an
existing node or marker on the flexible body.Note: The marker
defining the joint can then be offset fromthis location or attached
to multiple nodes by modifying it. It is not required that the
joint be located on an attachmentpoint in FEM. It is good modeling
practice, however, toconnect joints at attachment points. You can
avoid nodal mismatch by: Using consistent numbering Paying
attention to alignment issuesS4-5ADM710, Section 4, July
2008Copyright 2008 MSC.Software CorporationJOINT CONNECTION
LIMITATIONSS4-6ADM710, Section 4, July 2008Copyright 2008
MSC.Software CorporationJOINT CONNECTION LIMITATIONS (CONT.)
Workaround: Attach the joint to an intermediate dummy partthat is
fixed to the flexible body at a node.Note: The C++ options were
introduced in Adams/Flex 2003.Only the FORTRAN options were
available before the 2003release.* Starting with the 2005 release,
Adams/Solver (FORTRAN)will automatically introduce a dummy part
between the jointand the flexible body.S4-7ADM710, Section 4, July
2008Copyright 2008 MSC.Software CorporationABOUT DUMMY PARTS Dummy
parts Starting with the 2005 release, dummy parts are
automaticallycreated for Adams/Solver (FORTRAN) Only necessary if
you are using Adams/Solver (FORTRAN)2003 or a previous version of
ADAMS/Flex. Rigid parts with zero (or an insignificant amount of)
mass andinertia, and are also referred to as massless links or
phantomparts. Not physical parts of your model. Must be constrained
in all six DOF (commonly accomplishedwith a fixed joint). Although
they do not increase the DOF count of your model,they do increase
the number of system equations you aresolving. The dynamic behavior
is not negatively affected bydummy parts. The use of some modeling
elements is only possible throughthe use of dummy parts.S4-8ADM710,
Section 4, July 2008Copyright 2008 MSC.Software CorporationABOUT
DUMMY PARTS (CONT.)Flex body connects todummy part through fixed
jointMotion is applied to theWRIST_PIN dummy partS4-9ADM710,
Section 4, July 2008Copyright 2008 MSC.Software CorporationABOUT
FORCESS4-10ADM710, Section 4, July 2008Copyright 2008 MSC.Software
CorporationABOUT FORCES (CONT.)* The floating marker cannot be on a
flexible body. Thereaction force cannot act on a flexible body.**
The joint's J marker cannot be on a flexible body.***Starting with
the 2005 release, Adams/Solver (FORTRAN)will automatically
introduce a dummy part between the forceand the flexible
body.Workaround: Attach the joint to an intermediate dummy partthat
is fixed to the flexible body at a node. Modal force (MFORCE)
Allows you to apply forces in the modal domain (covered inModal
Applied Force and Preloaded Flexible Bodies).WS3-1ADM710, Workshop
3, July 2008Copyright 2008 MSC.Software CorporationWORKSHOP
3PERFORMING AN ADVANCED SWAPWS3-2ADM710, Workshop 3, July
2008Copyright 2008 MSC.Software CorporationWS3-3ADM710, Workshop 3,
July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 3
PERFORMING AN ADVANCEDSWAP Problem statement The product
engineering department is investigating ways ofreducing the cost of
the robot. One designer suggested hollowingout a portion of the
forearm (a lightening hole). The FEA expertmeshed the proposed
design change, and now you have toincorporate it into your robot
model. You must redefine theproperties of the current flexible body
by referencing a differentMNF, and then simulate the new design.
Mechanism information This model is the flexible robot model you
completed in Workshop2Performing a Simple Swap. The FOREARM is
modeled as flexible (robot_arm_easy.mnf) andyou must replace it
with a different flexible body(robot_arm_hard.mnf). Input motions
haven't changed.WS3-4ADM710, Workshop 3, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP
(CONT.)Existing flexible bodyNew flexible body Lightening
holeWS3-5ADM710, Workshop 3, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP (CONT.) Setting up
the model To set up the model:1. Run Adams/View from the directory,
exercise_dir/mod_04_robot.2. From the same directory, import the
model command file,robot_mod4_start.cmd.This is the model you
completed in Workshop 2 Performing a Simple Swap. Swapping flexible
bodies To swap flexible bodies:1. From the Build menu, point to
Flexible Bodies, and then select Flex to Flex.2. Right-click the
Flexible Body text box, point to Flexible_Body, point toBrowse, and
then select FLEX_FOREARM.3. Right-click the MNF File text box,
point to Browse, and then selectrobot_arm_hard.mnf.WS3-6ADM710,
Workshop 3, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP (CONT.)4. Select 3
Point Method.5. To make it easier to see the nodes, set the render
mode to shaded.6. Follow the instructions in the Status bar to
select the following nodes inthe order listed:Note: To select the
right nodes, zoom and rotate the model as needed.Right-click near
the nodes to ensure that you are selecting the
correctnode.N325N52N34 N30N10N3WS3-7ADM710, Workshop 3, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 3 PERFORMING AN
ADVANCEDSWAP (CONT.)4. Select OK.WS3-8ADM710, Workshop 3, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 3 PERFORMING AN
ADVANCEDSWAP (CONT.) Running a flexible body simulation Before you
run a simulation, prepare the flexible body by reviewingmodes and
setting various simulation settings, such as: Turning off execution
graphics to prevent Adams/View from trying toanimate when it is
done solving. Keep in mind that when you runAdams/View
interactively, you can turn off the execution display tospeed up
your simulation. Make sure that you are using Adams/Solver (C++).
To prepare the flexible body:1. Briefly review the mode shapes to
see the modal content that will beused in the analysis.(Modes 1
through 6 have been automatically disabled because theyare rigid
body modes.)2. Verify that Inertia modeling is set to the default,
Partial coupling.WS3-9ADM710, Workshop 3, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP
(CONT.) To prepare for simulation:1. From the Simulate menu, select
Scripted Controls.2. From the bottom of the dialog box, select
Simulation Settings.3. Verify that Category is set to Executable.
Set Executable to External.4. Set Category to Output. Set Save
Files to Yes. In the File Prefix text box, enter robot_mod4.These
settings run the simulation externally.5. To prevent Adams/View
from animating while it is solving, setCategory to Display. Set
Update Graphics to Never. To display the textual output to the
Information window, set ShowMessages to Yes.6. Select
Close.WS3-10ADM710, Workshop 3, July 2008Copyright 2008
MSC.Software CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP
(CONT.) To set the variable to use Adams/Solver (C++): To run
Adams/Solver externally using Adams/Solver (C++), you must set
anenvironment variable on your computer. On UNIX, do one of the
following: In the Adams Toolbar, set Solver Select to C++. Set the
following environment variable using the appropriate shell
commandsfor your version of UNIX: set MDI_SOLVER_SELECT to CXX. On
Windows:1. From the Start menu, point to Settings, and then select
Control Panel.2. Double-click System.3. Select the Advanced tab.4.
Select Environment Variables.5. Check to see if an environment
variable named MDI_SOLVER_SELECT=CXXalready exists on your
computer. If it already exists, then skip Step 6.6. In the
Environment Variables dialog box, create a new user variable as
follows:Variable Name = MDI_SOLVER_SELECTVariable Value = CXX (for
Adams/Solver (C++))WS3-11ADM710, Workshop 3, July 2008Copyright
2008 MSC.Software CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP
(CONT.) To run the simulation:1. Run a scripted simulation using
FLEX_SCRIPT.This script uses the following Adams/Solver
commands:SIM/STATICSINTEGRATOR/SI2,GSTIFF,
HMAX=1E-3SIMULATE/TRANSIENT, DURATION=1.7, DTOUT=1.0E-02The
analysis will take a while.2. When the analysis has finished, write
down the CPU time displayed atthe bottom of the Information window:
Elapsed time = ____________seconds.After the analysis has finished,
Adams/View updates the strip
chart,FOREARM_LATERAL_DEFL.WS3-12ADM710, Workshop 3, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 3 PERFORMING AN
ADVANCEDSWAP (CONT.) Inspecting the analysis results You now
inspect the analysis results and compare them with theresults from
Workshop 2Performing a Simple Swap. To inspect the analysis
results:1. Launch Adams/PostProcessor.2. Load the animation in the
viewport and animate the simulation of therobot.3. Select the
Contour Plots tab, and verify that Contour Plot Type is setto
Deformation.4. Right-click FLEX_FOREARM, and then select Select.5.
In the Property Editor, select the Flex Props tab and set the
DatumNode to 4001.6. Create a new page and plot the measure
FOREARM_LATERAL_DEFLversus time.7. Import the .res file,
robot_module3.res, created in Workshop 2 Performing a Simple Swap:
From the File menu, point to Import, and then select Results File.
In the File Name text box, browse for
mod_03_robot/robot_module3.res. In the Model Name text box, enter
.robot.8. Select OK.WS3-13ADM710, Workshop 3, July 2008Copyright
2008 MSC.Software CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP
(CONT.)9. Create another new page (page_3) to plot the measure
again. Thisallows you to compare results from several runs.10.
Verify that Surf is selected.11. Plot these results onto page_3 so
the curves are overlaid. Simulation: robot_module3, Last_Run
Source: Result Sets Result Set: FOREARM_LATERAL_DEFL Component:
Q12. After the curves are displayed, clear the selection of Surf so
the plotwon't be overwritten later.WS3-14ADM710, Workshop 3, July
2008Copyright 2008 MSC.Software CorporationWORKSHOP 3 PERFORMING AN
ADVANCEDSWAP (CONT.) Investigating analysis with disabled modes Run
the model again with modes disabled based on strain
energycontribution. To disable modes:1. Return to Adams/View.2.
From the Flexible Body Modify dialog box, select auto.3. In the
Analysis Name text box, enter .robot.Last_Run.4. In the Energy
Tolerance text box, enter 1e-3.5. Select OK.6. Select Modal ICs to
see which modes have been disabled.7. Review some of the modes that
have been disabled. We suggest youreview modes 16 through 21.8.
Close the Flexible Body Modify dialog box.WS3-15ADM710, Workshop 3,
July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 3
PERFORMING AN ADVANCEDSWAP (CONT.) To prepare and run the model:1.
In the Solver Settings dialog box, name the output file
prefix,robot_mod4_se_disabled.2. Perform a simulation using
FLEX_SCRIPT.Again, the analysis will take a while. When it has
finished, write down the run time:CPU time used = ____________
seconds.3. Save the model to a binary file.4. Launch
Adams/PostProcessor.5. Automatically update the plots on page_2 and
page_3: From the File menu, select Replace Simulations. Select Add
Simulation. Set Update Pages to All.6. Look at the plot on page_2
and answer the questions: How has disabling the modes changed the
results?
_________________________________________________________________________________________________
Based on the CPU times you recorded, was this analysis faster or
slower than when themodel had all modes enabled?
_________________________________________________________________________________________________________________
Consider the repercussions of overzealously disabling modes based
on a singlesimulation.7. Exit Adams/View.WS3-16ADM710, Workshop 3,
July 2008Copyright 2008 MSC.Software CorporationWORKSHOP 3
PERFORMING AN ADVANCEDSWAP (CONT.) Optional tasks1. Disable some
modes that are obviously important and then runanother simulation.
What effect does it have on the simulation
results?________________________________________________________________________________________________________________________________________________________________________2.
In your directory, use xdiff (or equivalent) to difference the .adm
files:xdiff robot_module4.adm /robot_module3.adm.What is different?
Do the differences make
sense?________________________________________________________________________________________________________________________________________________________________________________________________________________________________WS3-17ADM710,
Workshop 3, July 2008Copyright 2008 MSC.Software
CorporationWORKSHOP 3 PERFORMING AN ADVANCEDSWAP (CONT.)3.
Difference the matrix files. Do the differences make
sense?____________________________________________________________________________________________________________________________________________________________________________________________________________________4.
See if you can reduce the CPU time by finding the rightcombination
of enabled and disabled modes. Did the resultsdegrade
significantly?__________________________________________________________________________________________________________S5-1ADM710,
Section 5, July 2008Copyright 2008 MSC.Software CorporationSECTION
5OPTIMIZING MNFS AND EXPORTINGLOADSS5-2ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationS5-3ADM710, Section 5,
July 2008Copyright 2008 MSC.Software CorporationOPTIMIZING MNFS AND
EXPORTING LOADS Whats in this section: Modal Neutral Files
Introducing Adams/Flex Toolkit MNF Browser Application Adams/Flex
Toolkit Optimization Options Command Line Flex Toolkit Exporting
FEA Loads FEMDATAS5-4ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationMODAL NEUTRAL FILES Are: Binary files
Platform independent Contain the following information: Generalized
mass and stiffness matrices Nodal masses/inertias Nodal coordinates
Inertia invariants Eigenvalues Mode shapes File comments and
version information Modal loads/preloads Attachment points Element
topology Units Stress/strain modesS5-5ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationINTRODUCING ADAMS/FLEX
TOOLKIT Adams/Flex Toolkit is a tool that allows you to viewthe
contents of your MNF and translate your MNFinto different formats.
You can access it through: Adams Toolbar (UNIX) Start menu
(Windows) Adams command line It contains the following
applications: MNF Browser MNF MTX Translator MSC MNF Translator MNF
MNF Optimizer MNFLOADS5-6ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationMNF BROWSER APPLICATION Allows you to
browse the contents of an MNF or MD DB (MDonly) and generate
reports Useful for debugging Note: The Index textbox will become
active if an MD DB has morethan one flexible body. Right-click in
the box to select a flexiblebody.S5-7ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationMNF MTX TRANSLATOR
Translates an MNF or MD DB (MD only) into anASCII matrix file,
which Adams/Solver uses Allows you to manually generate a matrix
file withouthaving to run Adams/View Note: We will be talking about
and using matrix files directlyin the next section.S5-8ADM710,
Section 5, July 2008Copyright 2008 MSC.Software CorporationMNF MNF
OPTIMIZER Allows you to decrease the size of your MNF or MDDB (MD
only) by decreasing the amount/type ofinformation stored in it
Adams/Solver will not solve the model faster;however, animations in
Adams/View will run faster Generates a new MNF or MD DB (MD only)
using theoptions that you choose Several options are available, as
shown on theAdams/Flex Toolkit Optimization Options pageS5-9ADM710,
Section 5, July 2008Copyright 2008 MSC.Software CorporationMNF MNF
OPTIMIZER (CONT.)S5-10ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationADAMS/FLEX TOOLKIT OPTIMIZATIONOPTIONS The
following are the options in the MNF MNFOptimizer: Invariants Units
Formatting Precision Stress and Strain Modes Rigid-Only MNF
Automatic ManualS5-11ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationINVARIANTS Sets which inertia invariants
should be computed andstored in the MNF Fast Set - Corresponds to
partial coupling (5 and 9 are notcomputed) Full Set - Calculates
and stores all invariants None - None of the invariants are stored
in the MNF.Adams/Solver recalculates the invariants needed each
timeyou write out your matrix files. Notes: The None option is not
valid when you are using theautomatic or manual optimizing methods.
If you select Fast Set, the newly generated MNF will neverbe able
to recover a full set of invariants.S5-12ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationUNITS Adams/View and
Adams/Solver use SI units as theirinternal units. Original -
Preserves your current units in your MNF. If youroriginal units
differ from SI, Adams/Flex will have to performunit scaling as it
performs different operations. This candegrade performance
noticeably. SI - Converts your MNF into SI units. Improves
performanceif original units differ from SI.S5-13ADM710, Section 5,
July 2008Copyright 2008 MSC.Software CorporationFORMATTING Platform
specific Turns off the extra coding needed to make the MNF
platformindependent. Can be done if the MNF will not be
transferredto other platforms. Standard portable Keeps the extra
code needed to make the MNF platformindependent.S5-14ADM710,
Section 5, July 2008Copyright 2008 MSC.Software
CorporationPRECISION Double This is the default option in
Adams/Flex. The numericalvalues stored in the MNF are in double
precision. Single Optionally, an MNF can be generated using
single-precision.This reduces the MNF size by 50%, and speeds up
anyprocess that requires obtaining information from the MNF.For
example, animation of flexible bodies and creating
MTXfiles.S5-15ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationSTRESS AND STRAIN MODES If stress (strain)
recovery was requested from the finite elementprogram when
generating the MNF, the MNF contains grid pointstresses (strains)
for every mode. The collection of grid pointstresses (strains) for
a given mode is referred to as a stress(strain) mode. Typically,
stress (strain) values are requestedfrom the finite element program
for a subset of nodes in theMNF. You can specify how the MNF stores
stress (strain)modes, particularly for nodes where stress (strain)
was notrequested from the finite element program: Sparse - The
optimized MNF only stores stresses (strains)for nodes that were
retained in the optimized MNF and forwhich stress (strain) values
existed in the original MNF. If anode had zero values for stresses
(strains) in the originalMNF, and that node was retained in the
optimized MNF, thezeroes are written to the optimized
MNF.S5-16ADM710, Section 5, July 2008Copyright 2008 MSC.Software
CorporationSTRESS AND STRAIN MODES (CONT.) Full - The optimized MNF
stores nodal stresses and strainsfor all nodes that were retained
in the optimized MNF. Fornodes that did not have stress (strain)
values, the optimizedMNF stores zeroes. Remove zero entries - The
MNF only stores non-zerostresses (strains) for nodes that exist in
the optimized MNF.If you have an MNF that has several zero entries
in thestress (strain) modes, this option can significantly reduce
thesize of the MNF.S5-17ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationRIGID-ONLY MNF Depending on the component
and application, thesize of the MNF can be very large, can
exceedseveral gigabytes, and be difficult to manage. If youare in
the process of building your Adams/Flex bodymodel, you may consider
treating the body as rigiduntil you are confident in your model
assemblyprocess. If temporarily using a rigid body formulationfor
an Adams/Flex body makes sense, you candrastically reduce the size
of the MNF by selectingRigid-Only MNF.S5-18ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationRIGID-ONLY MNF (CONT.)
Rigid-Only MNF creates a reduced MNF that onlycontains enough
information to build a rigidizedflexible body. With this MNF, you
cannot build anAdams/Flex body with Constant, Partial, or Fullmodal
formulations, but it may be convenient to workwith while you are
assembling and verifying yourmodel. When you are confident in your
model, youcan easily replace the reduced MNF with the
fullMNF.S5-19ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationAUTOMATIC Removes excessive nodal detail
from the MNF Note: The invariants must be stored in the MNF to use
thisoption. Removing Internal Solid Element Geometry -Removes all
internal node and element graphics formodels made with solid
elements Graphical performance of Adams/View is greatly enhanced
Mesh Coarsening Algorithm: Mesh Resolution - Combines mesh elements
that aresmaller than a fraction of the total component
size:S5-20ADM710, Section 5, July 2008Copyright 2008 MSC.Software
CorporationAUTOMATIC (CONT.) Diagonal dimension of original mesh =
1000*sqrt(2) = 1414.21 mm Mesh coarsening resolution is set to 15%
= 1414.21 * .15 = 212.13 mm Therefore, any element whose diagonal
is smaller than 212.13 mm iscombined with its neighboring element
to produce a larger element.Multiple elements are combined to
satisfy this parameter. The result is acoarser mesh. For our
example, 4 (100 mm * 100 mm) elements were combined toproduce a
larger element with a diagonal of 282.84.Original mesh Mesh
coarsened 15%S5-21ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationAUTOMATIC (CONT.) Mesh Coarsening
Algorithm...: Face Smoothing - Controls the angle between
adjacentfaces, below which Adams/Flex should merge faces: Range: 0
to 45 degrees For example: During the coarsening algorithm,
adjacent elements weremerged together if the resulting angle, phi,
was less than 45degreesOriginal face Face smoothed 45
degreesS5-22ADM710, Section 5, July 2008Copyright 2008 MSC.Software
CorporationAUTOMATIC (CONT.) Remove Collinear Points - Controls the
removal ofintermediate nodes on the straight edge of a face.
Retained Node List - Specify a list of nodes thatAdams/Flex should
not remove during coarsening. Note: Only visible nodes can be used
to place markers,joints, and so on, onto the flexible body.
Therefore, makesure to include relevant nodes.Original mesh Mesh
with colinear points Mesh without colinear pointsS5-23ADM710,
Section 5, July 2008Copyright 2008 MSC.Software CorporationMANUAL
Removes excessive nodal detail from the MNF througha user-defined
sketch of the mesh Sketch File - Contains a list of surfaces,
two-dimensional lines,and specific nodes to define the graphics of
the .mnf. Color resolution of the flexible body animation is
reduced. OpenGL applies color information to each of the nodes
present forthe flexible body. Then, it interpolates the colors
between thenodes. If your flexible body is only represented by a
couple ofnodes, then the color resolution will be reduced. The
invariants must be stored in the MNF to use this option. Useful
option when animation speed or file size is moreimportant than the
visual representation of the flexible body. Note: Only visible
nodes can be used to place markers, joints,and so on, onto the
flexible body. Therefore, make sure toinclude relevant
nodes.S5-24ADM710, Section 5, July 2008Copyright 2008 MSC.Software
CorporationSKETCH FILE 2Number of total faces 4 1 11 121 111 4
total nodes defining the face. The faceconnects nodes 1, 11, 121,
and 111. 1 61 1 node defining this face. The face just contains
node 61.11112111111112111161 61S5-25ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationCOMMAND LINE FLEX
TOOLKIT adamsmdr3 -c flextk on UNIX systems or adamsmdr3 flextkon
Windows systems. MNFLOAD Apply a distributed load to an MNF.
MNFXFORM Translating, rotating, or mirroring an MNF or MD DB.
MNFRES Recovering nodal displacement, velocity, or accelerationof a
flexible body.S5-26ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationMNFLOAD APPLICATION Load can be applied to
the flexible body using the MFORCEstatement. (We will talk about
the MFORCE statement inContacts and Modal Forces.) The MNFLOAD tool
can only be accessed through thecommand-line version of Adams/Flex
Toolkit Note: A distributed load can be added to an MNF when the
FEApackage creates the original MNF. All FEA programs that
supportAdams/Flex do not support this capability. Therefore,
theMNFLOAD tool was created as a workaround. Whenever possible,you
should create the distributed load within the FEA packagebecause it
will include the residual vector. The MNFLOAD toolcannot calculate
the residual vector; therefore, a portion of the loadwill not be
applied to the flexible body. For more information on theresidual
vector see the Applied Forces section. mnfload existing.mnf new.mnf
loadfileS5-27ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationMNFXFORM MNFs and MD DBs have data defined
with respect to the FE origin. MNFXFORM translates, rotates, or
mirrors the MNF or MD DB with respect tothe FE origin. mnfxform
[-offset d] [-id nid n1 n2 n3 ...] : -t for translation, -r for
rotation, or -m for mirror. : MNF or MD DB : Output MNF or MD DB :
-p px py pz Specify a point P-r rx ry rz Specify a point R-s sx sy
sz Specify a point S-v vx vy vz Specify a Vector V-d dist Specify
Distance dist-a angle Specify Angle (Anti-clockwise in degrees)
[offset inc]: Optional argument to offset the interface node IDs by
inc. New interfacenode id will be old id plus inc. [-id nid n1 n2
...]: Optional argument to specify new interface node IDs. nid is
thenumber of new IDs will be specified, n1 n2 ... are the new IDs.
Example: mnfxform.exe -m input.mnf output.mnf -v 1 0 0 -p 0 0 0
-offset 1This example mirrors input.mnf about yz plane and increase
the ids of the interfacenodes by 1. Then the transformed flexible
body is saved as output.mnf.S5-28ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationMNFRES mnfres [options]
[options] -t output results only until specified time. -n specify
flexible body when multiple exist. -g include rigid body motion -r
also report nodal rotations. Only effective when -g is not
specified -s report only on nodes listed in -L specify length unit
used in the Adams model. Abbreviation is accepted.Default value is
METER. -T specify time unit used in the Adams model. Default value
is SECOND.Abbreviation is accepted. -i report specific results.
values are: d: Nodal displacements v: Nodal velocities a: Nodal
accelerations : Adams result file. : MNF or MD DB Example: mnfres
-i d -n FLEX_BODY_1 example.res foo.mnfOutput all the nodal
deformation of flexible body FLEX_BODY_1, whose mnffile is foo.mnf
and the result file is example.res.S5-29ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationEXPORTING FEA LOADS
Allows you to export Adams/View dynamic load informationabout any
rigid or flexible body in your model to a (FEA)program The FEA
program uses the load information for a variety ofpurposes, such as
stress and strain analyses You can export load information into the
following formats: ANSYS Nastran ABAQUS DAC or RPC III (requires
Adams/Durability) The load files contain the following forces per
node selected: Joint reaction forces External (applied forces)
Gravitational forces Inertial forcesS5-30ADM710, Section 5, July
2008Copyright 2008 MSC.Software CorporationEXPORTING FEA LOADS
(CONT.) The load file contains a series of load cases (one
peroutput step) where the body is at an instantaneousdynamic
equilibrium Gravitational + external forces + joint reactions =
inertialS5-31ADM710, Section 5, July 2008Copyright 2008
MSC.Software CorporationEXPORTING FEA LOADS (CONT.) Steps:1. Run a
simulation - You must run a simulation so that Adams/View
candetermine the loads acting on the bodies in the model.2.
Identify the body - Specify which part whose load information you
would like toexport: Rigid bodies - Load information is calculated
relative to the marker that youselect.Note: This marker's location
must correspond to the origin of the body inthe FEA package.
Flexible bodies - Load information is calculated relative to the
LBRF.3. Identify the load points - Adams/View will automatically
select all points on thebody that have external loads applied to
them.4. Assign node ID's to load points - For a rigid body, you can
assign node ID'sto the load points that correspond to the node ID's
on the part in the FEAprogram (optional step).5. Specify the output
times - Determine the time interval from the specifiedsimulation
that you would like included in the load file (optional step). To
generate a complete loads history, leave the text box Output at
timesblank. For DAC and RPC III, you can enter start and end output
times.S5-32ADM710, Section 5, July 2008Copyright 2008 MSC.Software
CorporationFEMDATA You can also set up Adams/View to produce data
files ofcomponent loads, deformations, stresses, or strains for
inputto subsequent finite-element or fatigue-life analysis for
usein third-party products. Select Settings > Solver > Output
> More > Durability tospecify the type of file to
produce.WS4-1ADM710, Workshop 4, July 2008Copyright 2008
MSC.Softwa