基于弧長法的有限元逆算法及其在板料成形中的應(yīng)用.pdf

1、武漢理工大學(xué)碩士學(xué)位論文基于弧長法的有限元逆算法及其在板料成形中的應(yīng)用姓名：張靖暹申請學(xué)位級別：碩士專業(yè)：材料加工工程指導(dǎo)教師：蘭箭20090501武漢理工大學(xué)碩士學(xué)位論文ABSTRACTBlankdesignisimportantinsheetmetalstampingformingprocessItisthepremisetoobtaintheblankshapeofformingpartstoanalyzeformingdisto

2、rtiondegree，designtechnologyaswellasdraftprocessspecificationsReasonableblankshapeandsizecanobviouslyimprovetheinhomogeneousdeformationofblankandfullyexploitthemetalformingperformanceAmongthemethodsofblankdesign，theInver

3、sefiniteelementsApproach(IFEA)basedontotalstraintheoryonlyconsideringtheinitialandfinalstagesoftheparts，makesIFEAmethodveryfastandhigheffectiveUndersomespecificconditions，IFEAmethodcanquicklycalculateblankshape，finalstre

4、ss，strain，thicknesschangerateetc。InthepapeLthebasictheoryofsheetformingisfullystudiedThebasictheoryofIFEAandhowtooperateitarebrieflyintroducedThentheanisotropicconstitutiverelationunderproportionalloadingconditionandfiat

5、triangularmembraneelementsofconstantthicknesshavingthreenodesareadapted，andthentherelatedformulaisputforwardandtherelatedcomputerprogramisimplementedThenwegetthesolutionsofIFEAnon1inearequationsbytheABAQUSuserdefineeleme

6、ntoption(UEL)andit’SstandardcalculatorThekeyproblemofIFEAisthecalculationofinitialsolutions，becauseofthedifficultytoke印thetopologyofmeshelementsSotheinitialsolutionsnotonlyinfluencetherateofconvergencebutalsodeterminethe

7、resultsofIFEAarevalidornotArc1engthmethodisproposedtoresolvethedifficultywhichmapthefinalproductbythealelengthofeverynodeofproducttotheoriginalnodeThismethodcankeeptopologyofallthemeshelementsandimprovetheconvergenceofIF

8、EACylindricalcupanddoorlikeproductaresimulatedbyIFEAprogramThentheresultsarecomparedwiththosesimulatedbyincrementalsoftwareDYNAFORMandexperimentalThecomparisonsshowthatinverseapproach，whichcanbeusedtoevaluatethesheetmeta

9、lformingprocessquicklyisaneffectiveapproachforblankdesignSoitisagoodchoicetousethismethodintheinitialstageofdiedesignFinallytheIFEAbasedonthefournodeisoparametricelementiSdiscussedafterthetriangularmembraneelementandpart