黄永刚单晶塑性有限元umat子程序

SUBROUTINEUMAT(stress,statev,ddsdde,sse,spd,scd,1rpl,ddsddt,drplde,drpldt,2stran,dstran,time,dtime,temp,dtemp,predef,dpred,cmname,3ndi,nshr,ntens,nstatv,props,nprops,coords,drot,pnewdt,4celent,dfgrd0,dfgrd1,noel,npt,layer,kspt,kstep,kinc)cWRITE(6,*)'cNOTE:MODIFICATIONSTO*UMATFORABAQUSVERSION5.3(14APR'94)cc(1)Thelistofvariablesabovedefiningthe*UMATsubroutine,candthefirst(standard)blockofvariablesdimensionedbelow,chavevariablenamesaddedcomparedtoearlierABAQUSversions.cc(2)Thestatement:include'aba_param.inc'mustbeaddedasbelow.cc(3)Asofversion5.3,ABAQUSfilesusedoubleprecisiononly.cThefileaba_param.inchasalineimplicitreal*8and,sincecitisincludedinthemainsubroutine,itwilldefinethevariablescthereasdoubleprecision.Butothersubroutinesstillneedthecdefinitionimplicitreal*8sincetheremaybevariablesthatarecnotpassedtothemthroughthelistorcommonblock.cc(4)Thisiscurrentasofversion5.6ofABAQUS.cc(5)NoteaddedbyJ.W.Kysar(4November1997).ThisUMAThasbeencmodifiedtokeeptrackofthecumulativeshearstrainineachcindividualslipsystem.ThisinformationisneededtocorrectancerrorintheimplementationoftheBassaniandWuhardeninglaw.cAnylineofcodewhichhasbeenaddedormodifiedisprecededcimmediatelybyalinebeginningCFIXAandsucceededbyalinecbeginningCFIXB.AnycommentlineaddedormodifiedwillbegincwithCFIX.ccThehardeninglawbyBassaniandWuwasimplementedincorrectly.cThislawisafunctionofbothhyperbolicsecantsquaredandhyperbolicctangent.However,theargumentsofsechandtanharerelatedtothe*total*csliponindividualslipsystems.Formerly,theUMATimplementedthischardeninglawbyusingthe*current*sliponeachslipsystem.Thereinclaytheproblem.TheUMATdidnotrestrictthecurrentsliptobeacpositivevalue.Sowhenaslipwithanegativesignwasencountered,thectermcontainingtanhledtoanegativehardeningrate(sincetanhisancoddfunction).cTheUMAThasbeenfixedbyaddingstatevariablestokeeptrackofthec*total*sliponeachslipsystembyintegratinguptheabsolutevaluecofslipratesforeachindividualslipsystem.Thesesolutiondependentcvariablesareavailableforpostprocessing.TheonlyrequiredchangecintheinputfileisthattheDEPVARcommandmustbechanged.cC-----UsesingleprecisiononCraybyC(1)deletingthestatementIMPLICIT*8(A-H,O-Z);C(2)changingREAL*8FUNCTIONtoFUNCTION;C(3)changingdoubleprecisionfunctionsDSIGNtoSIGN.CC-----Subroutines:CCROTATION--formingrotationmatrix,i.e.thedirectionCcosinesofcubiccrystal[100],[010]and[001]CdirectionsinglobalsystemattheinitialCstateCCSLIPSYS--calculatingnumberofslipsystems,unitCvectorsinslipdirectionsandunitnormalstoCslipplanesinacubiccrystalattheinitialCstateCCGSLPINIT--calculatinginitialvalueofcurrentstrengthsCatinitialstateCCSTRAINRATE--basedoncurrentvaluesofresolvedshearCstressesandcurrentstrength,calculatingCshearstrain-ratesinslipsystemsCCLATENTHARDEN--formingself-andlatent-hardeningmatrixCCITERATION--generatingarraysfortheNewton-RhapsonCiterationCCLUDCMP--LUdecompositionCCLUBKSB--linearequationsolverbasedonLUCdecompositionmethod(mustcallLUDCMPfirst)C-----Functionsubprogram:CF--shearstrain-ratesinslipsystemsC-----Variables:CCSTRESS--stresses(INPUT&OUTPUT)CCauchystressesforfinitedeformationCSTATEV--solutiondependentstatevariables(INPUT&OUTPUT)CDDSDDE--Jacobianmatrix(OUTPUT)C-----Variablespassedinforinformation:CCSTRAN--strainsClogarithmicstrainforfinitedeformationC(actually,integralofthesymmetricpartofvelocityCgradientwithrespecttotime)CDSTRAN--incrementsofstrainsCCMNAME--namegiveninthe*MATERIALoptionCNDI--numberofdirectstresscomponentsCNSHR--numberofengineeringshearstresscomponentsCNTENS--NDI+NSHRCNSTATV--numberofsolutiondependentstatevariables(asCdefinedinthe*DEPVARoption)CPROPS--materialconstantsenteredinthe*USERMATERIALCoptionCNPROPS--numberofmaterialconstantsCC-----ThissubroutineprovidestheplasticconstitutiverelationofCsinglecrystalsforfiniteelementcodeABAQUS.TheplasticslipCofsinglecrystalobeystheSchmidlaw.TheprogramgivestheCchoiceofsmalldeformationtheoryandtheoryoffiniterotationCandfinitestrain.CThestrainincrementiscomposedofelasticpartandplasticCpart.TheelasticstrainincrementcorrespondstolatticeCstretching,theplasticpartisthesumoverallslipsystemsofCplasticslip.TheshearstrainincrementforeachslipsystemisCassumedafunctionoftheratioofcorrespondingresolvedshearCstressovercurrentstrength,andofthetimestep.TheresolvedCshearstressisthedoubleproductofstresstensorwiththeslipCdeformationtensor(Schmidfactor),andtheincrementofcurrentCstrengthisrelatedtoshearstrainincrementsoverallslipCsystemsthroughself-andlatent-hardeningfunctions.C-----TheimplicitintegrationmethodproposedbyPeirce,ShihandCNeedleman(1984)isusedhere.ThesubroutineprovidesanoptionCofiterationtosolvestressesandsolutiondependentstateCvariableswithineachincrement.C-----ThepresentprogramisforasingleCUBICcrystal.However,Cthiscodecanbegeneralizedforothercrystals(e.g.HCP,CTetragonal,Orthotropic,etc.).OnlysubroutinesROTATIONandCSLIPSYSneedtobemodifiedtoincludetheeffectofcrystalCaspectratio.CC-----Importantnotice:CC(1)ThenumberofstatevariablesNSTATVmustbelargerthan(orCFIXequalto)TEN(10)timesthetotalnumberofslipsystemsinCallsets,NSLPTL,plusFIVE(5)CFIXNSTATV