SECTION10LAGRANGIANBOUNDARYCONDITIONSSINGLEPOINTCONSTRAINT-SPCPreventsapointmovinginaparticulardirection.

MustbeinitializedintheCaseControlsection:SPC=SIDAnySPCnentriesnotselectedincasecontrolareignored.Thedisplacementcoordinatesystemoftheconstrainedgridpointdeterminesthedirectionthattheconstraintisappliedin.Canbeusedtomodelboundaryconditionsandplanesofsymmetry.Anycomponentingridcoordinatesystemcanbeconstrained.Componentsinagridcoordinatesystemarereferredbydigits1to6.Anycombinationispossible,e.g.23,156.

SPC=100

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SPC,100,27,123

SPC1,100,156,19,THRU,28ROTATIONALBOUNDARYCONDTION–SPC2Usedtomodelrotationalboundaryconditionsongridpoints.MustbeselectedinCaseControl

SPC=SID

SINGLEPOINTCONSTRAINTINLOCALCOORDINATES–SPC3Usedtodefineasinglepointconstraintinalocalcoordinatesystemoracascadeoftwolocalcoordinatesystems.MustbeselectedinCaseControl.

SPC=SIDENFORCEDMOTIONPrescribesthemotionofgridpoints.

Forceofpressureloading-TYPE=2inTLOAD1definition.MustbeselectedinCaseControl.Anyloading(TLOADnentry)notselectedinCaseControlisignored.

Enforcedmotioncanbeprescribedinalocalcoordinatesystem.ENFORCEDGRIDPOINTMOTIONSpecifiedpointscanhavetheirvelocityset.

Velocity-TYPE=2inTLOAD1definition

TLOAD1,100,110,,2,120DAREAdefinesmagnitudeoftranslationalorangularvelocityperDOF.FORCEdefinesmagnitudeanddirectionoftranslationalvelocity.MOMENTdefinesmagnitudeanddirectionofangularvelocity.Velocitycanvaryarbitrarilywithtime.TheTABLED1entrygivesthevariationofvelocity.

TLOAD=100

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TLOAD1,100,110,,2,120

TABLED1,120,,,,,,,,+

+,0.0,0.0,1.0,1.0,ENDT

FORCE,110,27,,-6.0,,1.0ENFORCEDMOTIONFORCEinCORDXXXIfonaFORCEentryaCIDisreferenced,theenforcedmotionisprocessedinalocalcoordinatesystem.

FORCE,110,27,2,-6.0,,1.0

RIGIDWALLS-WALLModelsarigidplanewhichspecified”slave”pointscannotpenetrate.Usedtomodelhard,undeformabletarget.Defineapointonthewallandavectorperpendiculartoit,pointingtowardsthemodel.Twokindsofcontact:PENALTYMethod:

Allowedpenetration.

Forceincreasesasnodespenetratedeeper.

Canhavefriction.KINEMATICMethod

NodesareputbackontheSurface.

ImpulseisappliedtoNodes.

Cannothavefriction.

WALL,101,0.0,0.0,0.0,0.0,0.0,1.0,102,+ +,PENALTY,0.2 SET1,102,1,THRU,1999TIEDCONNECTIONSTwomesheswithdifferentcoarsenessarepermanentlytiedtogetherduringtheanalysis.Allowsbeam,shellandsolidmeshestobetiedtogetherwithouttheneedforcoincidinggridpointlocations.Possiblegapsbetweenthemeshescanberequestedtobeclosed.Notrecommendedinareaswherestresspeaksorfailureisexpected.Threetypesoftiedconnections:TwosurfacestiedtogetherGridpointstiedtoasurfaceShelledgetiedtoashellsurfaceTWOSURFACETIEDTOGETHER(RCONN)Twosurfacesarepermanentlytiedtogetherduringtheanalysis.Mastersurface:alwaysattachedtothecoarsemesh.Slavesurface:alwaysattachedtothefinermesh.Lumpingforcesandvelocitiesaccordingtoshapefunctions.Forces:slavepoints

masterpointsVelocities:masterpoints

slavepointsExample:Twosolidsaretiedtogetheralongtheircommonsurface7and8. RCONN,1,SURF,SURF,7,8GRIDPOINTSTIEDTOASURFACE(RCONN)Individualgridpointsaretiedtoasurface.SlavesurfacetypeisGRIDandOPTIONmustbesettoNORMAL.Mastersurfacemustbedefinedasasetofsegments.Onlythetranslationaldegreesoffreedomaretied.Example:Thenode1to10ofabeammesharetiedtotheshellsurface7. RCONN,1,GRID,SURF,3,7,NORMAL SET1,3,1,THRU,10SHELLEDGETIEDTOASHELLSURFACEConnectsbeamsorshell-edgestoshellelements.SlavesurfacetypeisGRIDandOPTIONmustbesettoSHELL.Mastersurfacemustbedefinedasasetofsegments.Translationalandrotationaldegreesoffreedomaretied.Example:Theedgegridpoints1to10ofashellmesharetiedtotheshellsurfacenumber7. RCONN,1,GRID,SURF,3,7,SHELL SET1,3,1,THRU,10RIGIDBODYELEMENTS(RBE2)Definesasetofgridpointsthatformarigidbody.Thisentryallowsparticulardegreesoffreedomofasetofgridpointstobetiedtogethersothattheyalwaysmovethesameamount.Usedtomodelspotwelds,butelementscannotfail.Example:Nodes1to28willhavethesamedisplacementinxandz-directionasnode55. RBE2,12,55,13,1,THRU,28Insteadofdefiningtiedcomponents,itisalsopossibletousetheFULLRIGoption.Thiscausesthesetofgridpointstobehavelikeasinglerigidbodyelement.ThenameoftheRBE2willbecomeFR<number>.Example:Nodes1to28and55willbehavelikearigidbody.ThenamewillbeFR12. RBE2,12,55,FULLRIG,1,THRU,28KINEMATICJOIN(KJOIN)Shelltosolidgridpointconnection.Joinsshelltosolidelementsbyapplyingkinematicconditionstotheshellgridpoints.AnormalJOINwouldresultinahingeconnectioninwhichonlythetranslationalDOFsarecoupled.SolvestheclosureproblemforthedifferentDOFofshellandsolidelements.Constitutesstiffconnectionbetweenshellsandsolids

Stiffnessofjoinisuserdefined.Example:Kjoinbetweensolidnodes30,40and50andshellnodes32,42and52.Allnodeswithinatoleranceof1e-5areconnected.KJOIN,2,333,1e-5,,0.