ppt1、接触CONT-L07-AddFeatures

Thefollowingtopicsarecoveredinthislesson.Lessoncontent:AdditionalFeaturesWorkshop7:PipeReelAnalysis(IA)Workshop7:PipeReelAnalysis(KW),Lesson7:AdditionalFeatures,2hours,Bothinteractive(IA)andkeywords(KW)versionsoftheworkshopareprovided.Completeonlyone.,AdditionalFeatures,TieConstraintsRigidBodiesandContactAnalyticalRigidSurfacesPre-TensioningofCross-SectionsPressurePenetration,TieConstraints(1/7),InAbaqusfullyconstrainedcontactbehaviorisdefinedusingtieconstraints.Atieconstraintprovidesasimplewaytobondsurfacestogetherpermanently.Easymeshtransitioning.Surface-basedconstraintusingamaster-slaveformulation.Theconstraintpreventsslavenodesfromseparatingorslidingrelativetothemastersurface.,TieConstraints(2/7),Slavenodesthatcontactthemastersurfaceatthestartofthesimulationwillbetiedtoit.Slavenodesnotinitiallytiedwillremainunconstrainedthroughouttheanalysis;theywillnever“see”themastersurfaceandwillbeabletopenetrateit.Atableisprintedinthedata(.dat)filelistingeachslavenodeandthemastersurfacenodestowhichitwillbetiedifthepreprocessorprintoutofthemodeldataisrequested:*PREPRINT,MODEL=YES,TieConstraints(3/7),Usage:*TIE,NAME=name,POSITIONTOLERANCE=aslave,masterThePOSITIONTOLERANCEparameterhasthesameinterpretationastheADJUSTparameteronthe*CONTACTPAIRoption.Thedefaultvalueis5%ofthetypicalelementsizeinthemastersurface.,TieConstraints(4/7),Bydefault,allslavenodesinthetoleranceregionaremovedstrain-freeontothemastersurface.UseADJUST=NOiftheslavenodesshouldnotbemoved.*TIE,NAME=name,POSITIONTOLERANCE=a,ADJUST=NORotationsofthetiedslavenodesarenotconstrainediftheNOROTATIONparameterisused.Boundaryconditionsshouldnotbeappliedtothenodesontheslavesurfaceofatieconstraintpair;doingsowilloverconstrainthemodelatthosenodes.,TieConstraints(5/7),Example:Tubecrushproblem,TieConstraints(6/7),*TIE,NAME=TubePlateTie,POSITIONTOLERANCE=0.01,ADJUST=YES,Thesurface-to-surfacemethodisusedbydefault,TieConstraints(7/7),Node-basedsurfacesandtieconstraintsThenode-basedsurfacecanbeeitherthemasterortheslave.Ifanode-basedmastersurfaceisspecified:Theactualdistancefromaslavenodetothesurfaceistheclosestdistancetoanynodeonthemastersurface.ThedefaultPOSITIONTOLERANCEis5%ofatypicaldistancebetweenthemasternodes.,RigidBodiesandContact(1/12),RigidbodiesAbaqushasageneralrigidbodycapability.Arigidbodyisacollectionofnodesandelementswhosemotionisgovernedbythemotionofasinglenodecalleda“referencenode.”Anybodyorpartofabodycanbedefinedasarigidbody.Arigidbodycanundergoarbitrarilylargerigidbodymotions.Rigidbodiesarecomputationallyefficient.Theirmotionisdescribedcompletelybynomorethansixdegreesoffreedom.Therearenoelementcalculationsforelementsmakinguparigidbody.Modelabodyasrigidifitismuchstifferthanotherbodieswithwhichitwillcomeincontact.Forexample,rigidbodiesarecommonlyusedtomodeldiesinmetalformingsimulations.,RigidBodiesandContact(2/12),RigidbodyreferencenodeThereferencenodesdegreesoffreedomrepresentthemotionoftherigidsurface.Intwodimensions:threedegreesoffreedom(twotranslations,onerotation)Inthreedimensions:sixdegreesoffreedom(threetranslations,threerotations)Youcancontroltherigidbodysmotiondirectlybyprescribingboundaryconditions(displacement,velocity,acceleration)tothereferencenodesdegreesoffreedom.Itisalsopossibletoapplyconcentratedloadstothenode.Therigidbodycanbemadetorotateaboutthereferencenodebyprescribingtherotationaldegreesoffreedom.Indynamicsproblemswheretherigidbodymovesfreely,thereferencenodeshouldbeplacedatthecenterofmassoftherigidbody.Thelocationofthereferencenodeisirrelevantifitsrotationaldegreesoffreedomaresuppressed.Elementscanbeconnectedtothereferencenode.Forexample:AttachMASSand/orROTARYIelementstosimulatethemassand/orrotaryinertiaoftherigidbodyindynamicproblems.Attachspringelementstoremoverigidbodymotionorsimulateasupportingstructure.,RigidBodiesandContact(3/12),RigidbodygeometryThegeometryofarigidbodyisdefinedby:Meshingthebodywithnodesandelements(discreterigidbody)orRevolvingorextrudingatwo-dimensionalgeometricprofile(analyticalrigidsurface),RigidBodiesandContact(4/12),AnalyticalrigidsurfacesCanonlybeusedwithcontactpairsSurfacegeometryoflimitedshapeThreetypesofanalyticalsurfacesareavailable:Two-dimensionalrigidsurface.Three-dimensionalrigidsurfacethatisextrudedinfinitelyintheout-of-planedirection.Three-dimensionalsurfaceofrevolution.Detailsarediscussedinlater.,RigidBodiesandContact(5/12),DiscreterigidbodiesMoregeneralrigidbodiescanbeconstructedusingdiscretegeometry.Canbeusedwithbothgeneralcontactandcontactpairs.Mostelementtypescanbepartofarigidbody.Forexample,solidelementscanbeusedtomodelthesameeffectasdiscreterigidelementsaslongasarigidbodyconstraintisappliedtothesolidelements.Exampleofdefiningarigidbodycontainingsolidelements:*ELEMENT,TYPE=C3D8R,ELSET=SOLID1.*SOLIDSECTION,ELSET=SOLID,MATERIAL=STEEL*MATERIAL,NAME=STEEL*ELASTIC200.0E9,0.3*DENSITY7800.0,*RIGIDBODY,REFNODE=refPt,ELSET=SOLID,RigidBodiesandContact(6/12),RigidelementsLegacyfeaturetodefinediscreterigidbodies.Thesurfaceofthebodyismeshedusing:2-D:R2D2:planarstripRAX2:axisymmetricshell3-D:R3D3:triangularshellR3D4:quadrilateralshellPreferredmethodismeshingabodywithdeformableelementsandthenapplyingarigidbodyconstraint.,RigidBodiesandContact(7/12),Example:SuperplasticformingofaboxBoxdimensions:60”long,40”wide,20”deep.One-quarterofblankismodeled.BlankmodeledusingM3D4Relements.DiemodeledwithS3elements(declaredrigid).Blankmaterialiselastic-viscoplastic.Loading:gaspressurewithscheduleautomaticallyadjustedtoachievemaximumstrainrateof0.02/sec.,RigidBodiesandContact(8/12),RigiddieThedieismeshedwithS3elementswhicharedeclaredrigid.,*RIGIDBODY,ELSET=DIE,REFNODE=REF-PT*ELEMENT,TYPE=S3,ELSET=DIE:*SHELLSECTION,ELSET=DIE,MATERIAL=SUPRAL.001,RigidBodiesandContact(9/12),ContactinteractionwithgeneralcontactAsinglecontactinteractionusingthedefaultall-inclusiveelement-basedsurface*SURFACEINTERACTION,NAME=FRICTIONLESS*CONTACT*CONTACTINCLUSIONS,ALLEXTERIOR*CONTACTPROPERTYASSIGNMENT,FRICTIONLESS,RigidBodiesandContact(10/12),ContactinteractionwithcontactpairsIngeneralthesurfacecorrespondingtotherigidbodymustbethemastersurface.*CONTACTPAIR,INTERACTION=FRICTIONLESSSURFA,RSURF*SURFACEINTERACTION,NAME=FRICTIONLESS,*Exception:rigidsurfacesmadeupofdeformableelementsanddeclaredasrigidmaybeusedasslavesurfaces;however,itisrecommendedthatrigidsurfacesalwaysbethemastersurface,Automaticloading:deformedconfigurationafter35seconds,Automaticloading:deformedconfigurationafter61seconds,RigidBodiesandContact(11/12),RigidBodiesandContact(12/12),AnalyticalRigidSurfaces(1/9),Analyticalrigidsurfaces:Abaqus/CAEinterface,AnalyticalRigidSurfaces(2/9),Analyticalrigidsurfaces:Abaqus/CAEinterface(contd),ProfileissketchedintheSketchmodule.,ReferencepointassignedinthePartmodule.,AnalyticalRigidSurfaces(3/9),Analyticalrigidsurfaces:Abaqus/CAEinterface(contd),TheorderofthepointsusedtodefinethesketchisnotimportantintheGUIinterface.ThesideofthepartformingtheARSisdefinedindependently.,AnalyticalRigidSurfaces(4/9),Analyticalrigidsurfaces:KeywordsinterfaceDefinedusing*SURFACEand*RIGIDBODY.*SURFACE,NAME=RSURF,TYPE=SEGMENTSSTART,x0,y0LINE,x1,y1CIRCL,x2,y2,x3,y3.*RIGIDBODY,ANALYTICALSURFACE=RSURF,REFNODE=1001,Normalmustpointtowarddeformablebody,orderofsegmentsdeterminesnormaln,AnalyticalRigidSurfaces(5/9),AnalyticalrigidsurfacesmoothingSincerigidsurfacesarealwaysthemastersurfaceinacontactpair,theyshouldbesmoothedtoavoidconvergenceproblems.DefineasmoothingradiususingtheFILLETRADIUSparameter:*SURFACE,TYPE=SEGMENTS,NAME=RSURF,FILLETRADIUS=r,Note:InAbaqus/CAE,smoothingcanbeperformedusingtheCreateFillettoolwhensketchingthepartprofile.,AnalyticalRigidSurfaces(6/9),AvailabletypesofanalyticalrigidsurfacesTwo-dimensionalsegmentedsurface,composedoflines,circles,and/orparabolas.*SURFACE,TYPE=SEGMENTS,NAME=RSURFSTART,x1,y1.*RIGIDBODY,ANALYTICALSURFACE=RSURF,REFNODE=999,Coordinatesdefinesurfaceprofileandaregiveninthelocalsystem,Three-dimensionalanalyticalsurfacesrequiredefinitionofatwo-dimensionalprofileinalocalcoordinatesystem.Thefigureshowsathree-dimensionalinfiniterectangularprojectionofatwo-dimensionalprofile:,*SURFACE,TYPE=CYLINDER,NAME=RSURFxa,ya,za,xb,yb,zbxc,yc,zcSTART,x1,y1.*RIGIDBODY,ANALYTICALSURFACE=RSURF,REFNODE=999,Coordinatesdefinetwo-dimensionalsurfaceprofileandaregiveninthelocalsystemabove.,Coordinatesdefinelocalsystemforsurfacedefinition.Pointcisonthenegativelocalz-axis.,AnalyticalRigidSurfaces(7/9),AnalyticalRigidSurfaces(8/9),Three-dimensionalsurfaceofrevolution.*SURFACE,TYPE=REVOLUTION,NAME=RSURFxa,ya,za,xb,yb,zbSTART,x1,y1.*RIGIDBODY,REFNODE=999,ANALYTICALSURFACE=RSURFDefineaxisofrevolutionintheglobalcoordinatesystem.Definecross-sectionintwodimensionsusinglocalxy(rzinthefigure)axesdefinedabove.Surfaceisgeneratedbyrevolutionofthecross-sectionaboutthelocaly-axis.,AnalyticalRigidSurfaces(9/9),Pre-TensioningofCross-Sections(1/10),Thepre-tensioningcapabilitycanbeusedtosimulatethetighteningoffastenersthatareusedtoassembleastructure.Afastenerisidentifiedbymeansofapre-tensionsection,acrosswhichadesiredloadisappliedtotightenthefastener.,Pre-TensioningofCross-Sections(2/10),Thepre-tensionsectioniscontrolledwitha“pre-tensionnode”thathasonlyonedegreeoffreedomandisusedto:applyaloadacrossthepre-tensionsection;ortoapplyatighteningadjustment(displacement)ofthepre-tensionsection,whichalsoresultsinapreloadofthefastener,andtomaintainthetighteningadjustmentsothattheloadacrossthefastenercanincreaseordecreaseuponloadingoftheentirestructureTheloadortighteningadjustmentactsalongthenormaltothepre-tensionsection.Useconcentratedloadstoprescribeapre-tensionloadatthepre-tensionnode.Useboundaryconditionstoprescribeapre-tensiontighteningortomaintainthepre-tensionadjustmentduringfurtheranalysis.,Pre-TensioningofCross-Sections(3/10),Thetotalforcetransmittedoverthepre-tensionsectionisthesumofthereactionforce(identifiedasRF1)atthepre-tensionnode,plusanyconcentratedload(identifiedasCF1)atthatnode.Thestressdistributionacrossthepre-tensionsectioncanbeobtainedfromtheunderlyingelements.Thetighteningofthepre-tensionsectionappearsastheU1displacementofthepre-tensionnode.Pre-tensionsectionscanbedefinedinfastenersmodeledwith:ContinuumelementsBeamortrusselements,Pre-TensioningofCross-Sections(4/10),FastenermodeledwithbeamortrusselementsIfabeamortrusselementisusedtomodelthefastener,thepre-tensionsectionischosentobeinsideanelement.Thepre-tensiondirectionpointsfromthefirstnodeoftheelementtothelastnode(followingtheelementconnectivity).,Pre-TensioningofCross-Sections(5/10),Thenormalntothepre-tensionsection:IsbydefaultaunitvectororientedfromthefirstnodetothelastnodeoftheelementCanbegivendirectlybytheuserRemainsfixed,evenforlargedisplacementanalysisUsethe*PRE-TENSIONSECTION,ELEMENT=,NODE=optiontodefinethebeamortrusselementinwhichthepre-tensionsectionislocatedandtoassociatethepre-tensionnodewiththesection.Thenormalcanbespecifiedonthedatalineimmediatelyfollowingthe*PRE-TENSIONSECTIONoption.,Pre-TensioningofCross-Sections(6/10),FastenermodeledwithcontinuumelementsIfcontinuumelementsareusedtomodelthefastener,thepre-tensionsectionisdefinedwithasurfaceacrossthefastener.,pre-tensionnode,Pre-TensioningofCross-Sections(7/10),Thepre-tensionsection:Doesnothavetobecontinuous.Maybeconnectedtoelementsotherthancontinuumelementsaslongasonlycontinuumelementsareusedtodefinethepre-tensionsection.Thenormalntothepre-tensionsection:Bydefaultisorientedinthedirectionofthepositivesurfacenormal.Maybegivendirectlybytheuser.Hence,thepre-tensionsectiondoesnothavetobeorthogonaltothepre-tensiondirection.Remainsfixed,evenforlarge-displacementapplications.Usethe*PRE-TENSIONSECTION,SURFACE=,NODE=optiontoassociateapre-tensionsectionwithapre-tensionnode.Thenormalcanbespecifiedonthe*PRE-TENSIONSECTIONoptiondataline.Definethesurfacewiththe*SURFACEoption.,Pre-TensioningofCross-Sections(8/10),AssemblyloadsinAbaqus/CAE,Pre-TensioningofCross-Sections(9/10),Example:BoltedpipejointApre-tensionloadof15kNisappliedacrossthebolttoplacethegasketundercompression.,Pre-TensioningofCross-Sections(10/10),ContourofstressS22,PressurePenetration(1/13),Distributedpressurepenetrationloadsallowforthesimulationoffluidpenetratingbetweentwocontactingbodiesandapplyingfluidpressuresnormaltothesurfaces.Surface-basedcontactcanbeusedwiththiscapabilityforthree-dimensional,two-dimensionalandaxisymmetricproblems.Anycontactformulationcanbeused.,PressurePenetration(2/13),Definingpressurepenetrationloads(Keywords)ThetwosurfacesformingthecontactpairtowhichthepressurepenetrationloadsareappliedarespecifiedwiththeMASTERandSLAVEparametersonthe*PRESSUREPENETRATIONoption.Themastersurfacecanberigidordeformable.Matchingmeshes,althoughdesirable,arenotrequired.Thenodesontheslaveandmastersurfacesexposedtothefluidpressure,themagnitudeofthefluidpressure,andthecriticalcontactpressurearegivenonthedatalines.*PRESSUREPENETRATION,SLAVE=DOORSURF,MASTER=DOOR28,0.100,0.075,PressurePenetration(3/13),Definingpressurepenetrationloads(Abaqus/CAE),PressurePenetration(4/13),PressurepenetrationcriterionFluidwillpenetrateintothespacebetweenthecontactingbodiesfromoneormultiplelocations(nodes)thatareexposedtothefluid.Whenthecontactpressureataslavenodeislargerthanthespecifiedcriticalvalue,furtherfluidpenetrationbetweenthesurfacesiscutoff.Thecriticalcontactpressureisusedtoaccountfortheasperitiesonthecontactingsurfaces.,PressurePenetration(5/13),EffectofpenetratedfluidAtnodeswherethefluidhaspenetratedbetweenthesurfaces,thepressurepenetrationloadwillbeappliednormaltotheelementsurface.Ifthefullcurrentfluidpressureisappliedimmediately,theresultinglargechangesinthestrainsnearthecontactsurfacescancauseconvergencedifficulties.Toensureasmoothsolution,thefluidpressureisrampeduplinearlyoveratimeperiodfromzeropressurepenetrationloadtothefullcurrentmagnitude.Thedefaulttimeperiodischosentobe0.001ofthecurrentsteptime.ThePENETRATIONTIMEparametercanbeusedonthe*PRESSUREPENETRATIONoptiontospecifythetimeperiodtakenforthefluidpressurepenetrationloadtoreachthefullcurrentmagnitudeonnewlypenetratedsurfacesegments.Thepenetrationtimeshouldnotbeaverylargefractionofthetotalsteptime.Thepressurepenetrationcriterionisevaluatedatthebeginningofanincrementbeforeanynewincrementoffluidpressureisappliedtothesurfaces,whichmaycausefurtherfluidpenetration.Incrementsizesmayhavetobelimited.,PressurePenetration(6/13),Example:PressurepenetrationintoacardoorsealThesurface-basedpressurepenetrationcapabilityisusedtosimulateatypicalcardoorsealsabilitytofunction.Themodelusedinthisexampleisasimplifiedversionofarealseal.TherubbermaterialismodeledasanincompressibleMooney-Rivlinmaterial.Fourpressurepenetrationpathsareidentifiedinthemodel.,PressurePenetration(