Running ABAQUS 6.3

34 Pages·2014·0.23 MB·English

Running ABAQUS 6.3
ArulMBritto
December1,2003
Contents
1 Introduction 2
1.1 Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.1 ABAQUS/Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.2 ABAQUS/Explicit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 SuggestedCourseofAction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 DataPreparation 6
2.1 Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 ABAQUSInput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3.1 Exercise1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3.2 Exercise2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.4 SimpleMeshGenerationCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3 RunningABAQUS 20
3.1 RunningBatchJobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.2 RunningMediumSizedJobs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.3 RunningLargeJobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.4 ABAQUSEnvironmentFile:abaqus v6.env. . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.5 CheckingforErrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.6 KillinganABAQUSjob. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.7 CheckingtheLicenseServer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.8 RestartinganABAQUSRun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4 FileextensionsusedbyABAQUS 23
5 PrintedOutput 24
6 RunningABAQUS/Viewer 26
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.2 MeshPlots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.3 DisplacementPlotsandGettingHardCopies . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.4 ContourPlots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.5 PATHPlots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.6 X-YPlots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.7 CreatingaForceDisplacementPlot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.8 WritingOutResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1
CONTENTS CONTENTS
7 PostProcessingusingThirdPartyPrograms 31
7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.2 PostProcessingusingPATRAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
8 Troubleshooting 31
8.1 NoMessageFile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
8.2 BlankpagesinsteadofPlotsforhardcopy . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
8.3 BlueIconinsteadofDialogueBox. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
8.4 Bugs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9 FAQandOtherInfo 32
9.1 On-lineDocumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9.1.1 Keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9.1.2 UserManual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2
1 INTRODUCTION
1 Introduction
ABAQUS is a general purpose (cid:2)nite element program distributed by ABAQUS Ltd. It has a large
elementlibraryandiscapableofanalysisofavarietyofproblems(linear,nonlinear,static,dynamic,
structural and thermal). ABAQUS/CAEis an interactive graphical for running ABAQUS.Post pro-
cessingisprovidedbyaseparatemoduleknownastheViewer.
The main aim of this manual is provide an overview. It does not provide any instructions on
howtoruntheCAEmodule. Thishasbeencoveredextensivelyelsewhere. Howeveressentialuseof
ABAQUS/Vieweriscoveredbutbynomeanscomprehensive.
Theremainderofthissectiondealswiththe manuals,the commandstorunthe variousmodules
andhowtogoaboutrunninganABAQUSanalysisintheCambridgeUniversityEngineeringDepart-
ment’sTeachingSystem(T.S.)Computers.
Section 2 of this manual deals with the input to the ABAQUS Analysis module. Section 3 sum-
marisesthesystemdependentcommandsnecessarytorunABAQUSintheTeachingSystem. Section
4 lists the various (cid:2)les created during an ABAQUS run. Section 5 summarises the printed output.
Section6dealswiththepostprocessingfacilitiesavailablewithABAQUS.Section7dealswithpost-
processingusingthePATRANprogram.Section8dealswithhowtotroubleshootwhenyouencounter
problems.Section9coversfurtherinformationonadditionalmanuals,examplesandABAQUSFAQ’s.
ThishandoutismainlyaimedatABAQUS/Standardusers.Thereisnoequivalenthandoutforthe
ABAQUS/Explicitprogram.ABAQUS/Explicitusersshouldconsulttherelevantusermanuals.
1.1 Manuals
ManualsfortheABAQUSprogramlistedbelowareavailableinthecomputerroom.Askthecomputer
operators. AsetofthemanualsareavailableforreferenceonlyintheDPO(centralaisleshelves). The
on-line version of the manuals aremore comprehensive and more up-to-date. Some of the manuals
areonlyavailableon-line.
1.1.1 ABAQUS/Standard
1. GettingStartedwithABAQUS/Standard
2. ABAQUS/StandardUser’sManual(VolumesI,IIandIII)
3. Theory(commontobothStandardandExplicitversions)
4. ExampleProblemsManual
5. ABAQUSKeywordsManual
6. Veri(cid:2)cation
7. ABAQUS/CAEUser’sManual
1.1.2 ABAQUS/Explicit
1. GettingStartedwithABAQUS/Explicit
2. ABAQUS/ExplicitUser’sManual(VolumesIandII)
1.2 Programs
ABAQUS/StandardandABAQUS/ExplicitarebothavailableintheCUEDteachingsystemcomput-
ers. ABAQUS/CAEisthepre-processorandABAQUS/Viewerinthepostprocessor. PATRANisan
establishedpre-andpost-processorforABAQUS.
ABAQUS/Designisanewcapabilitywhichissuitableforparametricstudyandoptimisation.
3
1 INTRODUCTION 1.3 Commands
1.3 Commands
To(cid:2)ndoutaboutalltheoptionsthatareavailablewithABAQUSandthiswilllistalltheoptionsthat
can be used when running ABAQUS. See also sections 3.1.1, 3.2.1 to 3.2.11 of the ABAQUS User’s
manual(Volume1)formoreinformationonexecutionprocedures.Section3.3.1hasexamplesofusing
theabaquscommand.
abaqushelp
Toaccesstheon-lineinformationonthekeywords(moredetailsinsection9.1)
abaqusdoc
To (cid:2)nd out which examples make use of a particular key word, illustrated here with the keyword
dynamic,
abaqus(cid:2)ndkeywordjob=dynamic
*dynamic
* (cid:0) CR
(cid:1)
Theoutputwillbewrittentothe(cid:2)lereferredtobyjobandwiththeextensiondatiedynamic.dat.The
analysesdata(cid:2)leslistedinthis(cid:2)lecanbeobtainedusingtheabaqusfetchcommand.
Toextractacopyoftheexamplesorveri(cid:2)cationinputdatafromsection6.2.4.1
abaqusjob=6020401fetch
Torunthepre-processingprogramABAQUS/CAE
abaquscae
ItisalsopossibletosubmitthejobanddothepostprocessingfromABAQUS/CAEwithoutexiting
fromit.
TorunanABAQUSanalysis(bothABAQUS/StandardandExplicit)
abaqusjob=abcd1
TorunthepostprocessingprogramABAQUS/Viewer
abaqusviewer
TocreateanexecutablemodulefromauserwrittenFortranprogram(thiswouldcreateprog1.x)
abaqusjob=abcd1makeuser=prog1.f
Toruntheexecutablemodulecreatedusingthemakecommand:
abaqusprog1.x
TorunMSC/PATRAN
patran
For other ABAQUS commands see section 3.1.1 of the User’s manual Vol. 1. Section 3.3.1 has
examplesofitsuse.
1.4 Suggested CourseofAction
(cid:2) Newusers arerecommendedto readthrough section 1.1.2of User’s manual volume I. Section
1.2.2dealswithconventionsandunits.
TheGettingStartedwithABAQUS/Standardmanualisthebeststartingplacefornewusers.It
hasexamplesonlinear,non-linear,dynamic,plasticityandcontactproblems. Italsohasagood
introductiontotheuseofcontinuumelements,shellandbeamelements.
Foruserswhoarelaunchingthemselvesintotheir(cid:2)rstanalysistherelevantinformationforany
givenanalysisisspreadoverthemanyABAQUSmanuals.
Youneedtoreadalltherelevantsections,makenotesasyougoalongandalsofollowuponall
cross-referencesyoucomeacross.
Youneedto(cid:2)ndalltheinformationpertainingtothefollowingtopicsforyouranalysis
(cid:150) AnalysisType(Procedures)
(cid:150) ElementTypes
(cid:150) MaterialBehaviour
4
1 INTRODUCTION 1.4 SuggestedCourseofAction
(cid:150) Loading
(cid:150) BoundaryConditions
(cid:150) Output
Onlyafterreadingalltherelevantinformationareyouinapositiontorunyourownanalysis. It
isagoodideato(cid:2)ndanexamplewhichisclosesttoyouranalysisrequirement.
(cid:2) Chapter6oftheUsersmanualdealswiththedifferentanalysesandprocedures. Thisisagood
placetostart.
(cid:2) Chapter9givesanintroductiontothematerialbehaviour.Chapters10to12coverallthemate-
rialmodelsavailableinABAQUS.
ABAQUSprovidesabroadrangeofmaterialmodels. Section9.1.3hasmaterialmodel combi-
nationtableswhichishelpfulinshowingwhichmaterialpropertiescouldbecombinedtogether
andwhichcannotbe.
(cid:2) Chapter13 introduces the elementtypes. Look through chapter 13 to 15 of the above manual
toidentifytheelementtypestobeusedintheanalysis. Thissectionalsohasinformationonthe
typeofloading. Chapters16to18containsinformationonmorenon-generalspecialistelement
types.
Oncetheelementtypehasbeenidenti(cid:2)edinthesamesectionalistofactivedof,typeofloading
thatcanbeappliedtotheelementtypeandtheoutput parametersavailableforthese elements
canbefound.
(cid:2) LookthroughtheElementIndexinvolumeIIfortheelementtypes.LookthroughtheKeywords
Manualtocheckthevariouskeywords.Refertothesectionswhicharerelevanttoyouranalysis.
(cid:2) Chapter 19 (volume II) has information on loading and boundary conditions. Further infor-
mation on MPC (Multi Point Constraints) and contactproblem can be found in chapters 20 to
22.
(cid:2) Section4.1.1(VolumeI)dealswiththeoutputfromABAQUS.
(cid:2) SearchthroughthecontentsoftheExampleProblemsManualto(cid:2)ndthetopicofyouranalysis.
Using the on-line version is the ef(cid:2)cient way to carry out this task. Also search through the
KeywordIndexofthisvolume.
Example:*DRUCKER-PRAGER
withoutparameters:6020401602040A
Thesearethenamesoftheinput data(cid:2)leswheretheabovekeywordisused. Theseareforthe
examplesinsection6.2.4oftheExamplesManual.
(cid:2) LookthroughthecontentsoftheVeri(cid:2)cationmanualto(cid:2)ndthetopicofyouranalysis.
(cid:2) AnotherusefulsourceisthecoursenotesofthevariouscoursesrunbyABAQUSCompany.
(cid:2) Run an example problem and familiarise yourself with the various (cid:2)les and in the use of the
variousprogrammodules(ABAQUS,ABAQUS/CAE,ABAQUS/Viewer).
(cid:2) Startwithasimpli(cid:2)edsituationofyouranalysiswithveryfewelements,stepsandincrements.
Then the turnaround time while you debug the data and root out the errors will be shorter.
OnceyoufamiliariseyourselfwithABAQUSyoucanre(cid:2)nethemeshandaddcomplexitytothe
analysis.
(cid:2) Inordertofamiliariseoneselfwiththe6.3styleformatoftheinput(cid:2)lesection2.6.1De(cid:2)ningan
Assemblyintheusers’sManualVolume1isrecommendedreading. Thisisessentialreadingif
youneedtomodifytheinput(cid:2)lecreatedbyCAE.
5
1 INTRODUCTION 1.4 SuggestedCourseofAction
Solid Create
Pro/
ENGINEER Modeler Complex
Geometry
ascii ascii
cae
prt, asm
part assembly
ABAQUS Pre
PATRAN
CAE
Processing
ascii
Log file
inp
log ascii
Printed output Message file
dat ABAQUS msg
Analysis
ascii Restart
res
file
binary
Output
database odb binary Results
binary fil file
ABAQUS/ Post
PATRAN
Viewer Processing
ps ps
+ other formats + other formats
Modules
Represents files which are identified by the
extension names.
PS − Postscript files
Figure1:ABAQUS,PATRANandPro/ENGINEERPrograms
6
2 DATAPREPARATION
Create complex ABAQUS Pre
cae
Geometry CAE Processing
binary
ascii
inp
Message file
Printed output msg
dat ABAQUS Analysis
res
ascii
Restart
binary
file
odb Output
Database
binary
Post
ABAQUS ps
Processing
Viewer
Represents files which are identified by the
extension names.
PS - Postscript files
Figure2:ABAQUS/CAE,ABAQUS/ViewerandtheAnalysisModule
2 Data Preparation
Figure1showsthevariousABAQUSmodulesandtheinter-relationshipbetweenPATRAN,Pro/ENGINEER
programsandABAQUS.Asshowninthis(cid:2)guretheABAQUSinputdata(cid:2)le*.inpcanbecreatedby
PATRANinteractively.ItisalsopossibletousethemeshgenerationcommandsavailableinABAQUS
(section2.4).Ifyouareworkingwithcomplexand/or3-dimensionalgeometriesuseofeitherPATRAN
orFEMGENisrecommended.
Complex3dimensionalgeometriescanbecreatedinPro/ENGINEERandimportedintoPATRAN
andthenmeshedbeforeaABAQUSanalysis. ItisalsopossibletousethenewABAQUS/CAEmod-
ulewhichprovidesthecapabilityofbothasolidmodeller(Pro/ENGINEER)andapre-processor(PA-
TRAN).HoweverbecauseCAEisrelativelynewitdoesnotasyetcaterforthefullcapabilitiesoffered
bytheanalysismodules(ABAQUS/Standard&Explicit).
ABAQUS/CAE has solid modelling capabilities which may not be as comprehensive as that of
a solid modeler such as Pro/ENGINEER but never the less may be adequate for what most users
needfortheiranalysis. Italsohasanoptionwhereanykeywordoptionswhichisnotyetcateredfor
usingthemenubasedsystemcanbedirectlytypedinusingatexteditorfromwithinABAQUS/CAE.
TheadvantageofdoingthiswithintheABAQUSframeworkinsteadofoutsideisthattheABAQUS
databasedoesnotgetoutofstepwiththeinputdata.
Figure2showstheinter-relationshipbetweentheABAQUSAnalysismoduleandthenewpreand
post-processormodules.
AlternativelytheusercanrefertotheABAQUSUSER’smanualsI,IIandIIIandcreatetheinput
data(cid:2)le(*.inp)inatexteditorusingABAQUScommands.
Section2.4givessomesimplecommandsformeshgenerationprovidedwithintheABAQUSpro-
gramitself.
7
2 DATAPREPARATION 2.1 Units
ThePATRANandFEMGENprogramscanbeusedtogeneratethedata(cid:2)lesforstructuralandther-
malproblems.Howeverifyourequiretogeneratethedata(cid:2)leforananalysisinanyotherspecialised
(cid:2)elditmaynotbepossibletocreatethecompleteinputdata(cid:2)lereadyforanalysis. Youmayhaveto
createthedata(cid:2)leforastandardstructuralorthermalproblemandthenwriteoutthe*.inpdata(cid:2)le.
Theneditthis (cid:2)le using atexteditorandmakethe necessarychangesto the element types, material
propertiesbyreferringtotheABAQUSmanualsandthensubmittinganABAQUSjob.
Section 2.2explains what constitutes an ABAQUSinput data (cid:2)le for a simple static analysis of a
structuralproblem.Theinputdata(cid:2)leisillustratedforasimpleexample.
TypepatrantorunthePATRANprogram. Seethe(cid:147)Beginner’sGuidetoPATRAN(cid:148)onhowtouse
thePATRANprogram. TypefemruntoruntheFEMGVprogram. Seethe FEMGV5UserManualon
howtousethefemgenprogram.Atrainingguideisalsoavailable.
See also the CUED web pages under help / EngineeringPackages / (cid:2)nite elements/ Pre and
PostProcessingformoreinformationoneitheroftheseprograms.
2.1 Units
AquestionoftenaskediswhatunitsdoesABAQUSuse? Theanswerisitdoesnotuseanyparticular
units. InputparametersaresimplynumbersasfarasABAQUSisconcerned.
ThereisnodefaultsetofunitsassumedwithABAQUS.Theuserissupposedtochooseanappro-
priatesetofunits. ForstructuralproblemtheusershoulddecideonunitsforLength andForce. For
timedependentproblemstheunitforTimealsohastobechosen.
Example:
Length(Co-ordinates)- (metres)
(cid:0)
Force -(cid:1) (Newtons)
Time - (seconds)
(cid:2)(cid:4)(cid:3)(cid:6)(cid:5)
Thenalldependentparametersmustbespeci(cid:2)edinaconsistentsetofunits. Forexamplestiffness
shouldbespeci(cid:2)edin(cid:1)(cid:8)(cid:7) (Pascals)anddensityin (cid:7) .
(cid:0)(cid:10)(cid:9) (cid:11)(cid:13)(cid:12) (cid:0)(cid:15)(cid:14)
Itisnotagoodideatoselectanarbitrarysetofunitsatthebeginningandthenhopetosortoutthe
resultslater(Example: Co-ordinates-mm,Young’sModulus-GPa).
Quantity SI SI(mm) SI USUnit(ft) USUnit(inch)
Length
(cid:0) (cid:0)(cid:16)(cid:0) (cid:0) (cid:17)(cid:19)(cid:18) (cid:20)(cid:22)(cid:21)
Force (cid:1) (cid:1) (cid:1) (cid:23)(cid:25)(cid:24) (cid:23)(cid:25)(cid:24)
(cid:11) (cid:17) (cid:17)
Mass ( ) (cid:23)&% (cid:23)’(cid:24) (cid:7)
(cid:11)(cid:26)(cid:12) (cid:18)(cid:28)(cid:27)(cid:6)(cid:21)(cid:29)(cid:21)(cid:30)(cid:3) (cid:31)! "(cid:14)#(cid:11)(cid:13)(cid:12) (cid:18)(cid:28)(cid:27)(cid:6)(cid:21)(cid:29)(cid:21)(cid:30)(cid:3) $ (cid:12) (cid:17)($!(cid:9) (cid:20)(cid:22)(cid:21)
Time s s s s s
Stress (N/ ) (N/ ) (cid:23)’(cid:24) / ((cid:23)’(cid:24) / )
)+* (cid:0)(cid:10)(cid:9) ,-)+* (cid:0).(cid:0).(cid:9) (cid:11)/)+* (cid:17) (cid:17)(cid:19)(cid:18)(cid:28)(cid:9) 0(cid:19)$#(cid:20) (cid:17) (cid:20)(cid:22)(cid:21)(cid:30)(cid:9)
Energy ( J) (cid:23)’(cid:24) (cid:23)(cid:25)(cid:24)
1 (cid:0)21 (cid:31)! /34(cid:14) 561 (cid:17)(cid:19)(cid:18) (cid:17) (cid:20)(cid:22)(cid:21) (cid:17)
Density (cid:7) (cid:7) (cid:7) (cid:23)7% (cid:7) lbf (cid:7)
(cid:11)(cid:13)(cid:12) (cid:0) (cid:14) (cid:18)(cid:28)(cid:27)(cid:6)(cid:21)(cid:29)(cid:21)(cid:30)(cid:3) (cid:0).(cid:0) (cid:14) (cid:18)(cid:28)(cid:27)(cid:6)(cid:21)(cid:29)(cid:21)(cid:30)(cid:3) (cid:0) (cid:14) $ (cid:12) (cid:17)(cid:19)(cid:18) (cid:14) $ (cid:9) (cid:20)(cid:22)(cid:21)(cid:29)8
2.2 ABAQUSInput
Readthrough section1.1.2(ABAQUSUSER’smanualVolumeI)foranintroduction tothe ABAQUS
inputdata(cid:2)le.ThisisessentialreadingfornewusersofABAQUS.
TheinputtotheABAQUSprogram((cid:0) job-id .inpor*.inp)containsmodeldataandhistorydata.
(cid:1)
In the rest of the manual the second option of representing the job-id with an asterisk (*) will be
adopted. Modeldatade(cid:2)nesthe(cid:2)niteelementmodel: theelements,nodes,elementproperties,ma-
terial de(cid:2)nition - any data that speci(cid:2)es the model itself. History data de(cid:2)nes what happens to the
model-thesequenceofeventsorloadingsforwhichthemodel’sresponseissought.
InABAQUStheuserdividesthehistoryintoasequenceofsteps.Eachstepisaperiodofresponse
of a particular type - a static loading, a dynamic response, a soils consolidation transient etc. The
de(cid:2)nition of a step includes the procedure type (static stress analysis, transient heat transfer analysis
8
2 DATAPREPARATION 2.2 ABAQUSInput
etc),controlparametersfortimeintegrationorthenonlinearsolutionprocedures,theloadingandoutput
requests.
The procedure option de(cid:2)nes the type of analysis that will be carried out during a step. A pro-
cedure option is required for each step, and must follow immediately after the *STEP option. Any
mixtureofproceduresmaybeusedfromsteptostep;butonlyone procedureisallowedinanysingle
step.
*STATICisoneoftheprocedureoptionsusedfortheexamplehere. Itmeansitisastaticanalysis.
HerefollowsthelistofproceduresavailableinABAQUS(seesection6.1.1oftheUSERS’manual).
*BUCKLE
*COUPLED TEMPERATURE-DISPLACEMENT (steady state and transient)
*COUPLED THERMAL-ELECTRICAL (steady state and transient)
*DYNAMIC
*FREQUENCY
*GEOSTATIC
*HEAT TRANSFER (steady-state and transient)
*MASS DIFFUSION (steady-state and transient)
*MODAL DYNAMIC
*RANDOM RESPONSE
*RESPONSE SPECTRUM
*SOILS, CONSOLIDATION
*SOILS, STEADY STATE
*STATIC
*STEADY STATE DYNAMICS
*VISCO
*DYNAMIC, EXPLICIT
The ABAQUS/Explicit module is run when the procedure speci(cid:2)ed is dynamic, explicit. For all
otherprocedurestheABAQUS/Standardanalysisisrun.
Alldatade(cid:2)nitionsinABAQUSareaccomplishedwithoptionblocks-setofdatadescribingapart
of the problemde(cid:2)nition. The user chooses those options that arerelevantfor a particularanalysis.
Eachoptionisintroducedbyakeywordcard.Keywordcardsbeginwitha*incolumn1,followedby
thekeyword.Example: *MATERIAL.
Iftheoption requiresdatacards,they followthe keywordcard. Thesyntaxofkeywordanddata
cardsis de(cid:2)ned in section 1.2.1(ABAQUSUser’s manual I). Keywords may have parameters. Key-
wordcardsusethe format in which blanksareignored andthe commas (,)separatethe parameters.
Section2.1.1dealswithnodede(cid:2)nitionand2.2.1dealswithelementde(cid:2)nition.
Parametersaresometimes required (for example : on the *ELEMENToption which introduces a
list of element de(cid:2)nition, the parameterTYPE is required to tell what type of element - solid, shell,
beam,etc-isbeingde(cid:2)ned). Manyparametersareoptional. Parametersmayhavevalues.
Example: *MATERIAL,NAME=STEEL
ThisassociatesthenameSTEELwiththematerialde(cid:2)nition.
Anylinewhichhas**inthe(cid:2)rsttwocolumnsarecommentcards.Anynumberofcommentcards
can be placed anywhere in the data (cid:2)le. Use comment cards with explanations liberally wherever
necessary.Whenyoulookatthesedata(cid:2)lesafterawhileitwillbeeasiertocomprehendthedata.
Warning:Donotuseblanklinesasasubstituteforcommentlinestomaketheinput
data(cid:2)lemorereadable.Avoidblanklineswhichcouldleadtoerrors.
Whenexperimenting with somealternativessome ofthekeywordsanddatalines
canbetakenoutofexecutionbyinserting**inthe(cid:2)rst2columns. Thesecanthenbe
re-activatedlaterbyremovingthe**. Thisiseasierthan(cid:2)rstdeletingandthenhaving
tore-entertheselinesagain.
Warning Figure 3 shows the simple example problem being analysed. Figure 4 shows the
(cid:2)niteelementmeshusedfortheanalysis. Eachelementisa4-nodedquadrilateral.
9
2 DATAPREPARATION 2.2 ABAQUSInput
Theplateis1metresquare. Theunitsforlengthhasbeenchosentobemetres. The
forceischosentobeinNewtons. TheYoung’smodulusisthenspeci(cid:2)edin(cid:1)(cid:8)(cid:7) forconsistency. The
(cid:0) (cid:9)
densityisspeci(cid:2)edin (cid:7) .
5(cid:15)(cid:12) (cid:0)(cid:15)(cid:14)
100 N
1 m
Y
1 m
X
Figure3:Acantileverexample
100
7 8 9 Uy
U
x
3 4 node
5
6
4
1 2
Y
1 2 3
X
Figure4:FiniteElementMesh
The(cid:2)rstoptionisusuallytheheaderfortheanalysis: thisisgivenonthe*HEADINGoption. The
nextline will betakenasthe headingandthis will appearon eachpageofthe printedoutput (*.dat
(cid:2)le)whenABAQUShasrun. Itisagoodpracticetoincludealineexplainingtheunitsbeingusedfor
lengthandforceaspartoftheheading.
*HEADING
SQUARE PLATE SUBJECTED TO POINT LOAD
** Job name: cantilever Model name: Model-1
** Units : Length - m, Force - N, Stress - N/m2.
Thenextparameter*PREPRINTisoptional.
10