RBar...RBAR Tutorial RBAR Defined RBAR is an element type specific to the Sierra SD physics code and...
Transcript of RBar...RBAR Tutorial RBAR Defined RBAR is an element type specific to the Sierra SD physics code and...
RBARTutorial
RBARTutorial
RBARTutorial
RBARDefined
RBARisanelementtypespecifictotheSierraSDphysicscodeandasaresultthistutorialisonlyapplicablewhenusingSierra/SD(Salinas).Itisessentiallya“rigid”barelementthathasnoextension,torsion,orbending.Itisoftenaconvenientwaytotransferorapplyloads.
RBARTutorial
CreateaNewModel• ChooseFile->New->Modelinthemenu• ChooseNewModel thenNext• ChooseCreateFromTemplatethenNext• EnterRBAR astheModelName• ChoosetheSierraSDTemplates->StructuralDynamics->TopologyOptimization templateandthenFinish
RBARTutorial
CreatetheDesignDomain
• AttheCUBIT commandpromptcopyandpastethefollowingcommands(seeHintonnextslide):brickx10cylinderradius2height10sub2from1cylinderradius2.5height10webcut volume1toolvolume3deletevol 3imprintallmergeall
RBARTutorial
Hint:CubitConsole• Ifyoudon’tseetheCUBIT> promptintheconsolewindowyouarejustlookingatthewrongconsole(theremaybemultipletochoosefromloadedinPlatothatusethesingleconsolewindow).Clickontheiconatthetoprightoftheconsolewindowthatlookslikeacomputerscreentotogglethroughthedifferentconsolesthatarecurrentlyloaded.Oryoucanclickonthedownarrownexttothecomputerscreenicontoseeallofthecurrentlyloadedconsolesandchooseonefromthelist.
RBARTutorial
CreatetheMeshandRBARs• AttheCUBIT commandpromptcopyandpastethefollowingcommands(seeHintonnextslide):createvertex000vol allsize.5meshvol allmeshvert19block1jointvert19spidersurf10block2vol 4block3vol 1
• ClickontheGeometry/MeshnodeinthetreeandthenclicktheSave iconinthetoolbartosavethemodel
• The“block…joint”commandcreatestheblockwithRBARelementsconnectingthepoint0,0,0andeverynodeontheinteriorofthecylindricalsurface.
• Wewillapplyourloadingtothesinglevertexat0,0,0andtheRBARelementswilltransferthatloadtotheinteriorofthecylindricalsurface.
RBARTutorial
ApplyaForceLoad
• Selectandright-clickthevertex(seeHintonnextslide)inthemiddleofthecylindricalsurfaceandchooseApplyLoads->nodeset (thevertexistheonethatalloftheRBARelementsareconnectedto).• IntheSettings panelselectforce fromthedrop-downlistandenter00-1e5 intheboxtotherightandhitthereturnkey.
RBARTutorial
Hint:EntitySelection• Theselectionfiltertoolbarisatthebottomleftofthegraphicswindow.• Thereare3highlevelmodes:Geometry,Mesh,andExodus• Withineachhighlevelmodetherearevariousoptionsforfilteringwhatwillgetselectedbyclicksinthegraphicswindow.
Highlevelmodes
Filteroptionsforagivenhighlevelmode
RBARTutorial
CreateaFixedBC• Createanodeset fromthe8verticesatthe8cornersofthecubebytyping“nodeset 2vertex1to8” attheCUBIT prompt.• ChoosetheNodeset selectionfilteratthebottomofthegraphicswindow.• Selectnodeset 2byselectingandright-clickingonanyofthe8cornersofthecubeandchooseApplyBoundaryConditions->boundary• IntheSettings panelselectnodeset 2 andthencheckthefixedcheckbox.
RBARTutorial
AssignMaterialandElementType• ClickontheFEMMesh nodeinthetreeunderSierraStructuralDynamics->FiniteElementModel
• IntheSettings panelclickintheMaterial areanexttoBlocks2and3andselect1 fromthedropdownlist.Don’tsetamaterialforBlock1sinceitwillbetheRBARblock.IfthematerialforBlock1isalreadysetto1thenjustclickonitandselecttheblankentryfromthedropdownlist.
• ThenclickintheElement areanexttoBlock1andselectrbar fromthedropdownlist.
• ThenclickintheElement areanexttoBlocks2and3andselecthex8u fromthedropdownlist.
RBARTutorial
SettheTop.Opt.Parameters• ClickontheTopologyOptimization->TOPOLOGY-OPTIMIZATION nodeinthetree
• IntheSettingspanelright-clickanywhereintheParameters areaandchooseAdd->fixed_block_ids.Enter“12” (1and2separatedbyaspace)forthevalueofthefixed_block_ids parameterandhitthereturnkey.ThistellsPlatototreatblocks1and2asfixedandasaresulttheywillberespectedaspartofthefinalresult.Block1,theRBARblock,mustbesetasfixedsotheoptimizerdoesnottrytoperformoptimizationontheRBARelements.Astheyarenotvolumeelementsremovingoraddingmaterialdoesnotmakesense.
• IntheParametersareasetthefollowingparametervaluesbyclickingonthemandthenenteringthevalueintheeditfield:• volume_fraction =0.3• filter_scale =2.0• max_num_optimization_itr =30
RBARTutorial
RuntheOptimization• ClickontheSierraStructuralDynamics nodeinthetreetobringupthejobsubmissionpanelintheSettings view• ChooseSalinas asthecodeandthenchoosethemachineandexecutiontemplateyouwanttouse• IntheResources areamakesureRBAR.exo ischecked.Thisisthemeshfilethatwillbeusedintherun.• IntheCodeParameters areamakesureAutoPrune isuncheckedandNumberofRefines is0.Wewillnotbeusingpruningandrefininginthisexample.• ChooseanyotherpreferencesandlaunchthejobbyclickingonSubmitSimulationJob towardthetopofthepanel
RBARTutorial
ResultsTheresultsshouldlooksomethinglikethatshownbelow.