铝合金热锻模具结构中的应力应变演变过程分析

上海交通大学硕士学位论文铝合金热锻模具结构中的应力应变演变过程分析姓名：张瑜申请学位级别：硕士专业：材料加工工程指导教师：陈军20080101IDeform3DDeformMarcDeformMarcMarcIIMarcIIIRESEARCHOFTHESTRESSANDSTRAINEVOLUTIONONTHEALUMINUMALLOYHOTFORGINGDIEABSTRACTHotforgingdieplaysasignificantroleintherapidlydevelopingindustriessuchasautomotiveandmechanicalindustries.AlargeamountofhotworktoolsteelisconsumedinChinaeveryyearwiththetotalpriceofhundredsofmillionsofRMB.Workingunderhightemperatureandpressure,hotforgingdiesuffersfromcyclicmechanicalandthermalload,whichcausesthecomplicatedistributionofitsstrainandstressbothintimeandinspace.Thiscomplicatedistributionresultsinlowlifecycleofthedie.Recentyears,moreresearcheshavebeenfocusedontheforgingprocesses.However,theloadconditionofhotforgingdieitselfhasnotbeentakenenoughaccountinto.Soitisimportanttointensifytheresearchontheloadstatusofhotforgingdie.Inordertobetterreflecttheloadconditionofdieduringtheforgingprocess,anewsimulationmethodforhotforgingdieloadconditionanalysisbasedontheformingsimulationresultisproposedinthisthesis.Themainproceduresforthismethodareasfollowings:Firstofall,simulatetheformingprocesswithforminganalysissoftwareDeform3D.Duringthesimulation,thecoupledthermal-mechanicalmethodisused,andtheforgingpartistakenasrigid-plasticbodywhilethediesaretakenasrigidbodies.Whenthesimulationiscompleted,maptheformingforceofeachincrementfromtheparttothedies;Secondly,usethein-housedevelopedsoftwareinterfacetoextractnodalforceandtemperaturedatafromDeform3D’sKeyfileandwritethemintoIVMarc’sinputfile;Atlast,takethediesaselasticanddeformablebodies,conductstructuralanalysisinMarc.Thetemperature,stressandstraindistributionduringthewholeforgingprocesswillbeobtained.Thestressandstrainevolutionhistoryofaluminumalloyhotforgingdieduringthepre-forgingprocessismainlydiscussedinthisthesis,andcomparisonisconductedunderdifferentformingspeed.Fromthecomparison,conclusioncanbedrawn:thehighertheformingspeedis,thehigherthediestressis.Withtheproposedmethodologyinthisthesis,theexacttemperatureandforceboundaryconditionsforthediesareaddedtotheFEMmodelinMarc,andthestressandstrainhistoriesforeachnodeduringthewholeforgingprocessaredemonstrated.SinceMarcisaverypowerfulFEAanalysistool,itcanseverastheplatformforfurtherresearchesonhotforgingdie,hencetheproposedmethodologycanserveasthepreconditionstoanalyzetheabrasion,fatigueandotherconditionsofhotforgingdie.Besides,thisdiestructuralanalysismethodbasedontheformingsimulationresultsnotonlysavessimulationtimebutalsohasaverygoodsimulationconvergence,itprovidesafeasiblewayforotherdiestressandstrainanalysis.Thismethodcaneffectivelysupportdiedevelopmentandprovidesomeguidelinesforindustrialpractices.KEYWORDS:hotforgingdie,stress,strain,FEM□□(“√”)11.1208030005%~8%150~240200432624465%160[1]1[2][3]100kg8%[1][4]()[5]4000~50008000~1000050%[6]2[7][8]1.280[9]Kobayashi[10]1982Oh[11]WuAltan/ALPID[1213][14]/ParkKobayashi[15]YoonYang[16][17]B[18][19]Forming3[20]DEFORM[21]3J.H.KangArchard[2223]D.H.Kim[24]ArchardShinichiroFujikawa[25]Deform[26]BPBPMarc1/36[27]MSC.SuperformCoffin-Mansion[28]4ANSYS1.3MSC.SuperformDeform3DDeform3DMarc5MarcMarcFatigue1.4Deform3DMarc()DEFORMMSC.Marc62.12.1.12.1.22.1.3[29][30]7[26]2.2[3132]2.2.1[33][34]70%25%2%3%[35]2.2.282.2.32.2.49()2.32.4103.1()3.1.1[36](C.H.Lee)1973-(Levy-Mises)Mises()()(DEFORM)()()113.1.2()()(1)(2)Levy-Mises(3)(4)(5)(6)()3.1.3()VSPiSSPSuSPPiSu0iv[3638](1),0ijjσ=(3-1)(2).,.1()2ijijjivvε=+(3-2)12.ijε,vij.vji(3).'ijijελσ=(3-3)..32ελσ=(3-4)'ijσ.ε3-5σ3-6...2()3ijijεεε=(3-5)..3()2ijijσσσ=(3-6)(4)Yσ=(3-7)Y()sYfσε=(5)..0vijijεεδ==(3-8)13.vε(6)PSuSijjinpσ=(pS)(3-9)0iivv=(uS)(3-10)jnpS3.1.4()()()()(Markov)[3638]VS(3-2)(3-8)(3-9)(3-10).PiivSdVpvdSσεΠ=−∫∫(3-11)0δΠ=ivVS'ivijε′&ivijε&.()PijiivSUdVpvdSεΠ=−∫∫(3-12)()ijUε&00()ijijijijUddσεεσεσε′==∫∫&&&&(3-13)14LagrangeLagrangeLagrangeλ(3-11)(3-12)λmσLagrangeλmσ3N3N(N)LagrangeMM(M)αααα0.00010.001α510710ijσ′mσmνσαε=&[39]α(3-11)(3-12)2()2iivvvvdVpvdSdVασεεΠ=−+∫∫∫&&(3-14).2()()2PijiivvSvUdVpvdSdVαεεΠ=−+∫∫∫&(3-15)3.23.2.1[40]15(1)(2)(3)()(4)(5)()3.2.2[41](1),0ijjibσ+=(3-16)(2),,1()2ijijjiuuε=+(3-17)(3)()1ijijklklDεσ−=ijijklklDσε=(3-18)(4)(BC)iiuu=Su(3-19)ijjinpσ=Sp(3-20)ij(ij=123)xyz16ijσijεibiuipijklD3.2.31p∏[40]()[()()]()PiijiippVSuUudVudSεφψ==++∏∏∫∫1()2ijklijkliiiiVSpDbudVpudSεε=−−∫∫(3-21)(()ijUεijε(3-17)iu)(3-19)0pδ=∏(3-22)2c∏[40]()()uijmniiccVSVdVpudSσσ==−∏∏∫∫12uijklijkliVSCdVpudSσσ=−∫∫(3-23)170cδ=∏(3-24)3.3[40]3.3.1),,,(tzyxφtc∂∂φρ-)(xkxx∂∂∂∂φ-)(ykyy∂∂∂∂φ-)(zkzz∂∂∂∂φ-Qρ=0(Ω)(3-25)φφ=(1Γ)(3-26)xxnxk∂∂φ+yynyk∂∂φ+zznzk∂∂φ=q(2Γ)(3-27)xxnxk∂∂φ+yynyk∂∂φ+zznzk∂∂φ=)(φφ−ah(3Γ)(3-28)ρ(kg/m3)c(J/(kgK))t(s)kxkykz(xyz)(W/(mK))18Q(W/kg)nxnynz(,)tφφ=Γ1Γ(,)qqt=Γ2Γ(W/m2)h(W/(m2K))(,)aatφφ=Γ3Γaφaφ(3-25)1234xyz(3-26)1Γ(,)tφΓ(3-27)2Γ(,)qtΓq=0(3-28)3Γ1Γ+2Γ+3Γ=ΓΓΩ3.3.2Ωt(3-25)(3-26)(3-27)(3-28)1212[()()()]()()xyzxxyyzzckkkQdtxxyyzzdknknknqdxyzφφφφωρρφφφωφφωΩΓΓ∂∂∂∂∂∂∂−−−−Ω+∂∂∂∂∂∂∂∂∂∂−Γ+++−Γ+∂∂∂∫∫∫33[(()]0xxyyzzaknknknhdxyzφφφωφφΓ∂∂∂++−−Γ=∂∂∂∫(3-29)1ω2ω3ω1Γ19φφ=1ω=0ω=2ω=3ω=δφ(3-30)(3-29)1Ω2~4[()()()()xyzckkktxxyyzzφδφφδφφδφφδφρΩ∂∂∂∂∂∂∂+++−∂∂∂∂∂∂∂∫23]()0aQdqdhdδφρδφδφφφΤΤΩ−Γ−−Γ=∫∫