硕士论文-高强度钢板冲压模具偏载分析及拓扑优化设计

上海交通大学硕士学位论文高强度钢板冲压模具偏载分析及拓扑优化设计姓名：徐栋恺申请学位级别：硕士专业：材料加工工程指导教师：陈军20090501IULSAB-AVCABCNSC8632007AA04Z130-LS-DYNA-IIOptiStructNXCAD28%1-23ABSTRACTIIIOFFSETLOADANALYSISANDTOPOLOGYOPTIMIZATIONFORHIGH-STRENGTHSTEELSTAMPINGDIEABSTRACTLightweightistheinevitabletrendofautomobileindustrydevelopment.Researchresultsofautomobilelightweightfrommaininternationalprojects,suchasULSAB-AVC,ABCandNBC,indicatethatextensiveuseofhigh-strengthsteel(HSS)isaneffectivewayforvehiclestoachievemassreductionandimprovesafetyperformance.However,workingconditionsofstampingdiebecomeevenworseatthesametimebecauseofthemuchhigheryieldstrengthandtensilestrengthofHSS.Accordingtothissituation,engineersusuallytendtoenlargethesafetyfactortoguaranteethenormaloperationofstampingdie,however,whichincreasestheoverallweightofdiedirectlyandrisesupthemanufacturingcostsandoperationcostsindirectly.Inordertoovercomethenewchallengementionedabove,themaintaskofthisthesis,supportedbytheAdvancedTechnologyResearch&DevelopmentProgramoftheMinistryofScienceandTechnology,China(Grant#2007AA04Z130),istodevelopamethodofdiestructureoptimization,whichisbasedonnumericalsimulationofsheetmetalforming,diestructureanalysisandtopologyoptimizationofdiestructure,forthepurposeofreducingtheweightofthetool.Thebinderistheonlypartofthestep-likebottomedboxdrawingdieconsideredinthemethodologygeneration.Theproposedmethodcanbeappliedtotheanalysisandoptimizationofanyotherpartofthedrawingdieanalogously.ThemaincontentandconclusionofthisthesisshowasfollowingThestep-likebottomedboxdrawingdieisselectedastheresearchobjecttoconsidertheABSTRACTIVoffsetloadforstructureanalysisandoptimizationofstampingdie.Asensitivityanalysiscannotonlyclarifytheuseofwearplates,butalsorevealthefundamentalsourceofoffsetload.Firstofall,thisresearchencountersadifficultyofobtainingthelateralcontactforcebetweenwearplateswhichrespectivelybelongtopunchandbinderfromtraditionalrigidtooling-plasticsheetmetalFEmodelofsheetmetalformingsimulation.Apartialelastictooling-plasticsheetmetalFEmodelofsheetmetalformingsimulationisestablishedbyLS-DYNAtosolvetheproblemanditseffectivenessischeckedbypractice.Thenodeloads,extractedfromformingsimulation,areappliedtothestructuralanalysisFEmodelofbinderbyloadmappingmethod.Acreativeapproachistodealwiththecomplexcontactproblembyboundaryconditionsofforce,whichavoidsalongprocessofiterativecalculation.Onthebasisofthestructuralanalysisresults,adepthanalysisoftheforcecharacteristicsforbinderduringdrawingprocessandtheimpactoflateralcontactforceonbinderisdone.Uptonow,thepreliminaryworkfortopologyoptimizationofbinderisaccomplished.Basedonaboveresearch,aFEmodel,whichconsidersmultiplekeystepsofloadstoobtainamoreglobaloptimizationresult,isfoundedfortopologyoptimizationofbinder.ThestructuraloptimizationsolverOptiStructisusedtosolvetheproblem.Afteriterativecalculation,theinitialresultoftopologyoptimizationforbinderwillbere-designedbyNX.Finaloptimizedbindershowsaweightreductionofabout28%withlittleperformancedegradation.Inaddition,acomparisonofthetopologyoptimizationresultforbinderbetweenconsideringandnotconsideringlateralcontactforceshowstheimportanceoflateralcontactforcetobinderoptimization.Finally,theequivalentstresscurvesofthekeypointsonoriginalandoptimizedbinderareobtainedthroughtheexperimentofstrain-stressmeasurement.Althoughthesimulationresultsshowacertaindegreeoffluctuationinthecomparisonwithexperimentalresults,theirtrendsareconsistenttotheexperimentalresults.AndthisfirmlyprovesthereliabilityoftheABSTRACTVproposedsimulationmethod.Additionally,theresultoftopologyoptimizationreachestheinitialdesigntarget,whichisconfirmedwhencomparingtheexperimentalresultsoforiginalandoptimizedbinder.Inthisthesis,innovativepointsare1obtainingthelateralcontactforcebetweendifferentpartsofdiethroughthepartialelastictooling-plasticsheetmetalFEmodelofsheetmetalformingsimulation2dealingwiththecomplexcontactproblembyboundaryconditionsofforce,whichdependsontheloadmappingmethodinstructuralanalysisofstampingdie3consideringthemultiplekeystepsofloads,instructuraltopologyoptimizationofstampingdie,toobtainamoreglobaloptimizationresult.KEYWORDShigh-strengthsteelstampingdieoffsetloadofdiestructuralanalysistopologyoptimization11.11.1.120%2006600[1]2007879.15[2]200810008%960GDP2005GDP1.21%20071.66%2010GDP2.5%24%18%46%20061/62.3%20.642.81/3207020087147/2CO210%3%7%[3]2500kg750kg5km/L25km/LCO2400gCO2/km100gCO2/km[4][5]1.1.220901-1101-1[9]Table1-1Mainprojectsoflightweightautomobileabroadinrecentyears[9]%1PNGV302SuperLightCar403ULSAB-AVC204ABC305NSC20370%1-1251.8mm1.4mm220Mpa700Mpa[6]1-213%200Mpa600Mpa[6]1-11-2Fig.1-1RelationshipbetweenenergyabsorptionFig.1-2Relationshipbetweenmassandblankthickness/strengthreductionandmaterialstrength1994ULSABULSACULSASULSAB-AVC[7]ULSABULSACULSAS25%[8]ULSAB-AVCBodyinwhiteBIW100%60%20%[9]1-3ULSAB-AVCDualPhaseDP74%3%1%1200Mpa1520MpaMart41-3ULSAB-AVC[9]Fig.1-3HighstrengthsteelusedinULSAB-AVCproject[9]WorldAutoSteel2008MercedesC70%20%CO2FordFiestaMitsubishiLancerBIWAC[10]1.1.3DPAdvancedHighStrengthSteelAHSS1-4AHSSDPTRIP