在LSPrepost建立sph模型的详细过程

LS_Prepost关键操作模型建立立方体模型沿三个坐标轴方向的节点数立方体起始节点号：该Part第一个节点号码粒子密度Part编号起始坐标球体模型球体半径球心坐标球体沿三个坐标轴方向的节点数圆柱体模型轴向节点数径向节点数，一般设置相同圆柱高圆柱半径底部中心坐标方向坐标圆柱圆台/锥模型圆台/锥圆台顶部半径圆台底部半径轴向节点数径向节点数，一般设置相同圆台高底部中心坐标方向坐标参数定义*DATABASE_FORMAT计算结果输出数据库输出结果格式IFORMOutputformatforD3PLOTandD3THDTfiles:LS-DYNAdatabaseformat(default),:ANSYSdatabaseformat,:BothLS-DYNAandANSYSdatabaseformats.IBINARYWordsizeofthebinaryoutputfiles(D3PLOT,D3THDT,D3DRLFandinterfacefilesfor64bitcomputersuchasCRAYandNEC.:default64bitformat,:32bitIEEEformatRemarks:1.Thisoptionisnotavailableforeveryplatform.CheckLS-DYNABanneruponexecutionoftheprogram2.Byusingthisoptiononecanreducethesizeofthebinaryoutputfileswhicharecreatedby64bitscomputersuchasCRAYandNEC.二进制*DATABASE_EXTENT_BINARY结果输出控制数据库输出二进制结果NEIPHNumberofadditionalintegrationpointhistoryvariableswrittentothebinarydata-baseforsolidelements.Theintegrationpointdataiswritteninthesameorderthatitisstoredinmemory-eachmaterialmodelhasitsownhistoryvariablesthatarestored.Foruserdefinedmaterialsitisimportanttostorethehistorydatathatisneededforplottingbeforethedatawhichisnotofinterest.给实体增加附加综合的点历史变量二进制数据库，综合点数据目的是储存记忆每个材料模型使它拥有自己的历史变量。对于使用者而言，定义材料对于储存历史数据是很重要的，在数据储存前需要对其进行描绘。NEIPSNumberofadditionalintegrationpointhistoryvariableswrittentothebinarydata-baseforbothshellandthickshellelementsforeachintegrationpoint,seeNEIPHabove.给薄壳和厚壳单元增加附加综合的点历史变量二进制数据库，看下面的NEIPH。MAXINTNumberofshellintegrationpointswrittentothebinarydatabase,seealso*INTEGRATION_SHELL.Ifthedefaultvalueof3isusedthenresultsareoutputfortheoutermost(top)andinnermost(bottom)integrationpointstogetherwithresultsfortheneutralaxis.IfMAXINTissetto3andtheelementhas1integrationpointthenallthreeresultswillbethesame.Ifavalueotherthan3isusedthenresultsforthefirstMAXINTintegrationpointsintheelementwillbeoutput.Note:IftheelementhasanevennumberofintegrationpointsandMAXINTisnotsetto3thenyouwillnotgetmid-surfaceresults.SeeRemarksbelow.壳单元附加综合的点历史变量二进制数据库，可以参看*INTEGRATION_SHELL.如果采用默认值3，则结果输出的是最远（高）和最近（下）的综合点，结果包含中间轴坐标。如果设置为3，单元有一个综合点，则三个结果将相同。如果值超过3，则在单元中的第一个MAXINT综合点将会被输出。注意：如果单元拥有一系列综合点，而MAXINT没有被设置成3，则你将无法获得中间表面结果值，详见下面的附注。STRFLGSetto1todumpstraintensorsforsolid,shellandthickshellelementsforplottingbyLS-PREPOSTandASCIIfileELOUT.Forshellandthickshellelementstwotensorsarewritten,oneattheinnermostandoneattheoutermostintegrationpoint.Forsolidelementsasinglestraintensoriswritten.SIGFLGFlagforincludingstresstensorintheshellLS-DYNAdatabase::include(default),:exclude.EPSFLGFlagforincludingtheeffectiveplasticstrainsintheshellLS-DYNAdatabase::include(default),:exclude.RLTFLGFlagforincludingstressresultantsintheshellLS-DYNAdatabase::include(default),:exclude.ENGFLGFlagforincludingshellinternalenergydensityandthicknessintheLSDYNAdatabase::include(default),:exclude.CMPFLGOrthotropicandanisotropicmaterialstressandstrainoutputinlocalmaterialcoordinatesystemforsolids,shellsandthickshells.:global,:local.IEVERPEveryplotstatefor“d3plot”databaseiswrittentoaseparatefile.Thisoptionwilllimitthedatabaseto1000states::morethanonestatecanbeoneachplotfile,:onestateonlyoneachplotfile.BEAMIPNumberofbeamintegrationpointsforoutput.Thisoptiondoesnotapplytobeamsthatusearesultantformulation.DCOMPDatacompressiontoeliminaterigidbodydata::off(default),norigidbodydatacompression,:on,rigidbodydatacompressionactive,:off,norigidbodydatacompression,butnodalvelocitiesandaccelerationsareeliminatedfromthedatabase.:on,rigidbodydatacompressionactiveandnodalvelocitiesandaccelerationsareeliminatedfromthedatabase.SHGEOutputshellhourglassenergydensity::off(default),nohourglassenergywritten,:on.STSSZOutputshellelementtimestep,mass,oraddedmass::off(default),:outputtimestepsize,:outputmass,addedmass,ortimestepsize.Seeremark3below.N3THDTMaterialenergywriteoptionforD3THDTdatabase:off,energyisNOTwrittentoD3THDTdatabase,:on(default),energyiswrittentoD3THDTdatabase.IALEMATOutputsolidpartIDlistcontainingalematerials.:on(default)NINTSLDNumberofsolidelementintegrationpointswrittentotheLS-DYNAdatabase.Thedefaultvalueis1.ForsolidswithmultipleintegrationpointsNINTSLDmaybesetto8.Currently,noothervaluesforNINTSLDareallowed.Forsolidswithmultipleintegrationpoints,anaveragevalueisoutputifNINTSLDissetto1.PKP_SENFlagtooutputthepeakpressureandsurfaceenergycomputedbyeachcontactinterfaceintotheinterfaceforcedatabase.Toobtainthesurfaceenergy,FRCENG,mustbesentto1onthecontrolcontactcard.WhenPKP_SEN=1,itispossibletoidentifytheenergiesgeneratedontheupperandlowershellsurfaces,whichisimportantinmetalformingappli-cations.ThisdataismappedaftereachH-adaptiveremeshing.:Nodataiswritten:OutputthepeakpressuresandsurfaceenergybycontactinterfaceSCLPAscalingparameterusedinthecomputationofthepeakpressure.Thisparameterisgenerallysettounity(thedefault),butitmustbegreaterthan0.MSSCLOutputnodalinformationrelatedtomassscalingintotheD3PLOTdatabase.ThisoptioncanbeactivatedifandonlyifDT2MS<,seecontrolcard*CONTROL_TIMESTEP.ThisoptionisavailablestartingwiththesecondreleaseofVersion971.:Nodataiswritten:Outputincrementalnodalmass:OutputpercentageincreaseinnodalmassTHERMOutputofthermaldatatod3plot.Theuseofthisoption(THERM>0)maymakethedatabaseincompatiblewithother3rdpartysoftware.:(default)outputtemperature:outputtemperature:outputtemperatureandflux:outputtemperature,flux,andshellbottomandtopsurfacetemperatureRemarks:1.IfMAXINTissetto3thenmid-surface,inner-surfaceandouter-surfacestressesareoutputatthecenteroftheelementtotheLS-DYNAdatabase.Foranevennumberofintegrationpoints,thepointsclosesttothecenterareaveragedtoobtainthemidsurfacevalues.Ifmultipleintegrationpointsareusedintheshellplane,thestressesatthecenteroftheelementarefoundbycomputingtheaverageofthesepoints.ForMAXINTequalto3LS-DYNAassumesthatthedatafortheuserdefinedintegrationrulesareorderedfrombottomtotopevenifthisisnotthecase.IfMAXINTisnotequalto3,thenthestressesatthecenteroftheelementareoutputintheorderthattheyarestoredfortheselectedintegrationrule.Ifmultiplepointsareusedinplanethestressesarefirstaveraged.2.BeamstressesareoutputtotheLS-DYNAdatabaseifandonlyifBEAMIPisgreaterthanzero.Inthislattercasethedatathatisoutputiswritteninthesameorderthattheintegrationpointsaredefined.Thedataateachintegrationpointconsistsofthefollowingfivevaluesforelastic-plasticHughes-Liubeams:thenormalstress,?rr;thetransverseshearstresses,?rsand?tr;theeffectiveplasticstrain,andtheaxialstrainwhichislogarithmic.Forbeamsthatarenotelastic-plastic,thefirsthistoryvariable,ifany,isoutputinsteadoftheplasticstrain.ForthebeamelementsofBelytschkoandhiscoworkers,thetransverseshearstresscomponentsarenotusedintheformulation.NodataisoutputfortheBelytschko-Schwerresultantbeam.3.Ifmassscalingisactive,theoutputofthetimestepsizerevealslittleinformationaboutthecalculation.Ifglobalmassscalingisusedforaconstanttimestep,thetotalelementmassisoutput;however,ifthemassisincreasedsothataminimumtimestepsizeismaintained(DT2MSisnegative),theaddedmassisoutput.Also,seethecontrolcard*CONTROL_TIMESTEP.数据库*DATABASE_BINARY_D3PLOT结果输出时间步长输出时间步长DTTimeintervalbetweenoutputs.CYCLOutputintervalintimesteps(atimestepisacycle).FortheD3DRFLfileapositivenumber'n'willcauseplotdumpstobewrittenateveryn'thconvergencecheckintervalspeci-fiedonthe*CONTROL_DYNAMIC_RELAXATIONcard.NRNumberofRunningRestartFiles,RUNRSF,writteninacyclicalfashion.Thedefaultnumberisone,.thesamefileisoverwritteneachtime.LCDTOptionalloadcurveIDspecifyingtimeintervalbetweendumps.ThisoptionisonlyavailablefortheD3PLOT,D3PART,D3THDTandINTFORfiles.BEAMOptionflagfor*DATABASE_BINARY_D3PLOTorD3PART.:DiscretespringanddamperelementsareaddedtotheD3PLOTorD3PARTdatabasewheretheyaredisplayasbeamelements.TheelementglobalX,globalY,globalZandresultantforcesarewrittentothedatabase,:NodiscretespringanddamperelementsareaddedtotheD3PLOTorD3PARTdatabase.ThisoptionisusefulwhentranslatingoldLS-DYNAinputdeckstoKEYWORDinput.InolderinputdecksthereisnorequirementthatbeamandspringelementshaveuniqueID's,andbeamelementsmaybecreatedforthespringanddamperswithidenticalID'stoexist-ingbeamelementscausingafatalerror.ContactinterfaceswhicharebasedonpartIDsofseat-beltelementswillnotbeproperlygeneratedifthisoptionisused.:DiscretespringanddamperelementsareaddedtotheD3PLOTorD3PARTdatabasewheretheyaredisplayedasbeamelements(similartooption0).Inthisoptiontheelementresultantforceiswrittentoitsfirstdatabasepositionallowingbeamaxialforcesandspringresultantforcestobeplottedatthesametime.Thiscanbeusefulduringsomepost-processingapplications.NPLTCDT=ENDTIME/NPLTCappliestoD3PLOTandD3PARTonly.ThisoverridestheDTspecifiedinthefirstfield.PSETIDSET_PARTIDforD3PARTonly.IOOPTThisoptionappliestotheD3PLOTfileonly.Flagtogovernbehavioroftheplotfre-quencyloadcurvedefinedbyLCDT::Atthetimeeachplotisgenerated,theloadcurvevalueisaddedtothecurrenttimetodeterminethenextplottime(thisisthedefaultbehavior).:Atthetimeeachplotisgenerated,thenextplottimeTiscomputedsothatT=thecurrenttimeplustheloadcurvevalueattimeT.:Aplotisgeneratedforeachabscissapointintheloadcurvedefinition.Theactualvalueoftheloadcurveisignored*CONTROL_SPHSPHNCBSNumberofcyclesbetweenparticlesorting粒子分类搜索循环次数BOXIDSPHapproximationsarecomputedinsideaspecifiedBOX.WhenaparticlehasgoneoutsidetheBOX,itisdeactivated.Thiswillsavecomputationaltimebyeliminatingparticlesthatnolongerinteractwiththestructure.指定BOX内的SPH粒子参与计算。当某个SPH粒子位于BOX之外时，该粒子失效，通过消除某些不再与结构发生作用的粒子，可以节省计算时间。DTDeathtime.DetermineswhentheSPHcalculationsarestopped.粒子失效时间IDIMSpacedimensionforSPHparticles:SPH粒子的空间维数3for3Dproblems参数为3时，表示3维问题。2for2Dplanestrainproblems参数为2时，表示2维问题。-2for2Daxisymmetricproblems参数为-2时，表示轴对称问题。WhenavalueisnotspecifiedLS-DYNAdeterminesthespacedimensionautomaticallybycheckingtheuseof3D,2Dor2Dasisymmetricelements.当这个值无法自动指定LS-DYNA的维数，程序通过核对使用3维、2维或轴对称的单元来确定空间维数。MEMORYDefinestheinitialnumberofneighborsperparticle.Thisvariableisjustformemoryallocationofarraysduringtheinitializationphase.Duringthecalculation,someparticlescanrequestmoreneighborsandLS-DYNAwillautomaticallyadaptthesizeofthatvariable.Defaultvalueshouldapplyformostapplications.定义每个粒子的初始相邻粒子的数量，该变量只是在初始化阶段调整内存分配。在计算中，如果某些粒子需要更多的相邻粒子，LS-DYNA会自动调整该变量设置。默认值适用于大部分问题。FORMParticleapproximationtheory:粒子近似理论EQ.0:defaultformulation,默认公式EQ.1:remormalizationapproximation重归-近似化STARTStarttimeforparticleapproximation.ParticleapproximationswillbecomputedwhentimeoftheanalysishasreachedthevaluedefinedinSTART.粒子近似开始时间。当分析时间达到所设定的值时，粒子将开始计算。MAXVMaximumvalueforvelocityfortheSPHparticles.ParticleswithavelocitygreaterthanMAXVaredeactivatedSPH粒子速度最大值，如果速度超过该值，质点将会失效。CONTDefinesthecomputationoftheparticleapproximationbetweentwodifferentSPHparts:两个不同的SPH组之间粒子近似的计算设置。EQ.0:Particleapproximationisdefined(default)参数设为0计算粒子近似（默认值）EQ.1:Particleapproximationisnotcomputed.TwodifferentSPHmaterialswillnotinteractwitheachotherandpenetrationisallowed.参数设为1不计算粒子近似，两种不同的SPH材料不会发生相互作用，允许相互穿透。DERIVTimeintegrationtypeforthesmoothinglength:光滑长度的时间积分类型。*CONTROL_CONTACTCONTACTCard3isoptional.Thefollowingparametersarethedefaultvaluesusedbypartsinautomaticcontacts.Thesefrictionalcoefficientsapplyonlytocontacttypes:SINGLE_SURFACE,AUTOMATIC_GENERAL,AUTOMATIC_SINGLE_SURFACE,AUTOMATIC_NODES_TO_...,AUTOMATIC_SURFACE_...,andAUTOMATIC_ONE_WAY_....,andERODING_SINGLE_SURFACE.Alsosee*CONTACTand*thatthesedefaultvalueswilloverridethevaluesspecifiedforthesecontacttypesinthe*CONTACTsection.SLSFACScalefactorforslidinginterfacepenalties,SLSFAC::default=.1.RWPNALScalefactorforrigidwallpenalties,whichtreatnodalpointsinteractingwithrigidwalls,RWPNAL.Thepenaltiesaresetsothatanabsolutevalueofunityshouldbeoptimal;however,thispenaltyvaluemaybeveryproblemdependent.Ifrigid/deformablematerialsswitchingisused,thisoptionshouldbeusediftheswitchedmaterialsareinteractingwithrigidwalls.allnodesaretreatedbythepenaltymethod.Thisisrequiredforimplicitcalcula-tions.Sinceseven(7)variablesarestoredforeachslavenode,onlythenodesthatmayinteractwiththewallshouldbeincludedinthenodelist.theconstraintmethodisusedandnodalpointswhichbelongtorigidbodiesarenotconsidered.rigidbodiesnodesaretreatedbythepenaltymethodandallothernodesaretreatedbytheconstraintmethod.ISLCHKInitialpenetrationcheckincontactsurfaceswithindicationofinitialpenetrationinoutputfiles(seeremarksbelow)::thedefaultissetto1,:nochecking,:fullcheckofinitialpenetrationisperformed.SHLTHKShellthicknessconsideredintypesurfacetosurfaceandnodetosurfacetypecontactoptions,whereoptions1and2belowactivatethenewcontactalgorithms.Thethick-nessoffsetsarealwaysincludedinsinglesurface,constraintmethod,andautomaticsurfacetosurfaceandnodetosurfacecontacttypes(Seeremarksbelow.)::thicknessisnotconsidered,:thicknessisconsideredbutrigidbodiesareexcluded,:thicknessisconsideredincludingrigidbodies.PENOPTPenaltystiffnessvalueoption.FordefaultcalculationofthepenaltyvaluepleaserefertotheLS-DYNATheoryManual.:thedefaultissetto1,:minimumofmastersegmentandslavenode(defaultformostcontacttypes),:usemastersegmentstiffness(oldway),:useslavenodevalue,:useslavenodevalue,areaormassweighted,:sameas4butinverselyproportionaltotheshellmayrequirespecialscalingandisnotgenerallyrecommended.Options4and5canbeusedformetalformingcalculations.THKCHGShellthicknesschangesconsideredinsinglesurfacecontact::noconsideration(default),:shellthicknesschangesareincluded.ORIENOptionalautomaticreorientationofcontactinterfacesegmentsduringinitialization::defaultissetto1.:activeforautomated(part)inputonly.Contactsurfacesaregivenby*PARTdefinitions.:activeformanual(segment)andautomated(part)input.:inactivefornon-formingcontact.:inactiveforformingcontact.ENMASSTreatmentofthemassoferodednodesincontact.Thisoptionaffectsallcontacttypeswherenodesareremovedaftersurroundingelementsfail.Generally,theremovaloferodednodesmakesthecalculationmorestable;however,inproblemswhereerosionisimpor-tantthereductionofmasswillleadtoincorrectresults.:erodingnodesareremovedfromthecalculation.:erodingnodesofsolidelementsareretainedandcontinuetobeactiveincontact.:theerodingnodesofsolidandshellelementsareretainedandcontinuetobeactiveincontact.USRSTRStoragepercontactinterfaceforusersuppliedinterfacecontrolsubroutine,seeAppendixF.Ifzero,noinputdataisreadandnointerfacestorageispermittedintheusersubroutine.Thisstorageshouldbelargeenoughtoaccommodateinputparametersandanyhistoryinputdataisavailableintheusersuppliedsubroutine.USRFRCStoragepercontactinterfaceforusersuppliedinterfacefrictionsubroutine,seeAppendixG.Ifzero,noinputdataisreadandnointerfacestorageispermittedintheusersubroutine.Thisstorageshouldbelargeenoughtoaccommodateinputparametersandanyhistorydata.Thisinputdataisavailableintheusersuppliedsubroutine.NSBCSNumberofcyclesbetweencontactsearchingusingthreedimensionalbucketsearches.Defaultsrecommended.INTERMFlagforintermittentsearchinginoldsurface-to-surfacecontactusingtheintervalspecifiedasNSBCSabove::off,:on.XPENEContactsurfacemaximumpenetrationcheckmultiplier.Ifthesmallpenetrationcheckingoption,PENCHK,onthecontactsurfacecontrolcardisactive,thennodeswhosepenetrationthenexceedstheproductofXPENEandtheelementthicknessaresetfree,see*CONTACT_OPTION_...::defaultissetto.SSTHKFlagforusingactualshellthicknessinsinglesurfacecontactlogic-types4,13,15and26.Seeremarks1and2below.:Actualshellthicknessisnotusedinthecontacts.(default),:Actualshellthicknessisusedinthecontacts.(sometimesrecommendedformetalformingcalculations).ECDTTimestepsizeoverrideforerodingcontact::contacttimesizemaycontrolDt.:contactisnotconsideredinDtdetermination.TIEDPRJBypassprojectionofslavenodestomastersurfaceintypes:*CONTACT_TIED_NODES_TO_SURFACE,*CONTACT_TIED_SHELL_EDGE_TO_SURFACE,and*CONTACT_TIED_SURFACE_TO_SURFACEtiedinterfaceoptions::eliminategapsbyprojectionnodes,:bypassprojection.Gapscreaterotationalconstraintswhichcansubstantiallyaffectresults.SFRICDefaultstaticcoefficientoffriction(see*PART_CONTACT)DFRICDefaultdynamiccoefficientoffriction(see*PART_CONTACT)EDCDefaultexponentialdecaycoefficient(see*PART_CONTACT)VFCDefaultviscousfrictioncoefficient(see*PART_CONTACT)THDefaultcontactthickness(see*PART_CONTACT)TH_SFDefaultthicknessscalefactor(see*PART_CONTACT)PEN_SFDefaultlocalpenaltyscalefactor(see*PART_CONTACT)IGNOREIgnoreinitialpenetrationsinthe*CONTACT_AUTOMATICoptions.IntheSMPcontactthisflagisnotimplementfortheAUTOMATIC_GENERALoption.“Initial”inthiscontextreferstothefirsttimestepthatapenetrationisencountered.Thisoptioncanalsobespecifiedforeachinterfaceonthethirdoptionalcardunderthekeyword,*CONTACT.Thevaluedefinedherewillbethedefault.:movenodestoeliminateinitialpenetrationsinthemodeldefinition.:allowinitialpenetrationstoexistbytrackingtheinitialpenetrations.:allowinitialpenetrationstoexistbytrackingtheinitialpenetrations.However,penetrationwarningmessagesareprintedwiththeoriginalcoordinatesandtherecommendedcoordinatesofeachslavenodegiven.FRCENGFlagtoactivatethecalculationoffrictionalslidingenergy::donotcalculate,:calculatefrictionalenergyincontactandstoreas“SurfaceEnergyDensity”inthebinaryINTFORfile.Convertmechanicalfrictionalenergytoheatwhendoingacoupledthermal-mechanicalproblem.WhenPKP_SEN=1onthekeywordcard*DATABASE_EXTENT_BINARY,itispossibletoidentifytheenergiesgeneratedontheupperandlowershellsurfaces,whichisimportantinmetalformingapplications.ThisdataismappedaftereachH-adaptiveremeshing.SKIPRWGFlagnottodisplaystationaryrigidwallbydefault.:generate4extranodesand1shellelementtovisualizestationaryplanarrigidwall.:donotgeneratestationaryrigidwall.OUTSEGFlagtooutputeachbeamspotweldslavenodeanditsmastersegmentforcontacttype:*CONTACT_SPOTWELDintotheD3HSPfile.:no,donotwriteoutthisinformation.:yes,writeoutthisinformation.SPOTSTPIfaspotweldnodeorface,whichisrelatedtoa*MAT_SPOTWELDbeamorsolidelement,respectively,cannotbefoundonthemastersurface,shouldanerrorterminationoccur:no,continuecalculation,:yes,printerrormessageandterminate,:no,deleteunconstrainedweldandcontinuecalculation.SPOTDELIfthenodesofaspotweldbeamorsolidelementareattachedtoashellelementthatfailsandaredeleted,thentheattachedspotweldelementisdeletedifthisflagison.Thereisasmallcostpenaltyrelatedtothisoptiononnon-vectorprocessors.Onvectorprocessors,however,thisoptioncansignificantlyslowdownthecalculationifmanyweldelementsfailsincethevectorlengthsarereduced.:no,donotdeletethespotweldbeamorsolidelement,:yes,deletetheweldelementswhentheattachedshellsononesideoftheelementfail.SPOTHINOptionalthicknessscalefactor.Ifactive,defineafactorgreaterthanzero,butlessthanone.Prematurefailureofspotweldscanoccurduetocontactofthespotweldedpartsinthevicinityofthespotweld.Thiscontactcreatestensileforcesinthespotweld.Althoughthisseemsphysical,thecompressiveforcesgeneratedinthecontactarelargeenoughtofailtheweldintensionbeforefailureisobservedinexperimentaltest.Withthisoption,thethicknessofthepartsinthevicinityoftheweldareautomaticallyscaled,thecontactforcesdonotdevelop,andtheproblemisavoided.WerecommendsettingtheIGNOREoptionto1or2ifSPOTHINisactive.ThisoptionappliesonlytotheAUTOMATIC_SINGLE_SURFACEoption.ISYMSymmetryplaneoptiondefaultforautomaticsegmentgenerationwhencontactisdefinedbypartID’s::off,:donotincludefaceswithnormalboundaryconstraints.,segmentsofbrickelementsonasymmetryplane).Thisoptionisimportanttoretainthecorrectboundaryconditionsinthemodelwithsymmetry.NSERODFlagtouseone-waynodetosurfaceerosion:usetwo-wayalgorithm:useone-wayalgorithmRWGAPSFlagtoaddrigidwallgapstiffness,seeparameterRWGDTHbelow.:addgapstiffness:donotaddgapstiffnessRWGDTHDeathtimeforgapstiffness.Afterthistimethegapstiffnessisnolongeradded.RWKSFRigidwallpenaltyscalefactorforcontactwithdeformablepartsduringimplicitcalculations.ThisvalueisindependentofSLSFACandRWPNAL.IfRWKSFisalsospecifiedin*RIGIDWALL_PLANAR,thestiffnessisscaledbytheproductofthetwovalues.ICOVInvokesthecovariantformulationofKonyukhovandSchweizerhofintheFORMINGcontactoption.Thisoptionisavailableinthethirdrevisionofversion971,butisnotrecom-mendedsinceitisstillbeingimplemented.:standardformulation(default):covariantcontactformulation.SWRADFSpotweldradiusscalefactorforneighborsegmentthinning:neighborsegmentsnotthinned(default):TheradiusofbeamspotweldsarescaledbySWRADFwhensearchingforcloseneighborsegmentstothin.ITHOFFFlagforoffsettingthermalcontactsurfacesforthickthermalshells:Nooffset,ifthicknessisnotincludedinthecontacttheheatwillbetransferredbetweenthemid-surfacesofthecorrespondingcontactsegments(shells).:O