简介：Lightweightdesignisoneofthedevelopmenttrendsoftheautomobileindustry.AneffectivewaytoachievelightweightautobodiesistouseAHSS(advancedhighstrengthsteel)forthesafetycomponentsofautomobiles.ThisstudyhastakendoorsillreinforcementsmadeofmartensiteAHSSastheobject,andperformedresearchontheAHSSrollformingtechnologiesandprototypedevelopmentoftypicalasymmetricopencomponents.Bymeansoffiniteelementanalysis(FEA)andsimulation,studieshavebeencarriedoutonthespringbackandedgewavedefectsduringAHSSrollforming,andanoptimizedprocessdesignhasbeenachieved.Thegenerationmechanismsofverticalbows,horizontalcambers,twists,pre-punchedholedistortionandcutendflarehavebeenanalyzed,andsolutionstothesedefectshavebeengiven.Inaddition,tesingoftherollformingprocessforAHSShasbeenconductedandtypicalsampleswithrequireddimensionalaccuracyhavebeenmanufactured.Thisstudyhasprovidedtechnicalsupportforthelarge-scaleapplicationofAHSS.

简介：ThemetalsprayformingprocesswasexaminedusingmathematicalsimulationandverifiedthroughtheprototypingevaluationatBaosteel'stestanddevelopmentfacilities.Themathematicalmodelcomprisedoffoursections,includingjetgasflowinthedepositionchamber;singledropletbehavioralongitstrajectorypath;probabilityandstatisticalanalysisofdropletmassbehavior,andforecastoftheshapeandtemperaturedistributionofthebilletduringthesprayformingprocess.

简介：Inthisstudy,theformabilityoftransformation-inducedplasticity(TRIP)steelisstudiedduringdeep-drawingprocesseswithpreforming.Theeffectsofpreformingontheminimumthicknessofcanareinvestigatedwithaconstitutivemodelaccompanyingstrain-inducedmartensitetransformationinprestraincondition.TheconstitutivemodelhasbeenimplementedintoABAQUS/UMATforanalysisofTRIPsteel-formingprocesses.TheresultsshowthatpreformingslightlyinfluencesthethicknessuniformityofTRIPsteel...

简介：Sprayformingisanewtypeofmetalmaterialformingprocess,whichcanproducemetalblankssuchasbillet,tube,plateetc.Amathematicalmodelhasbeendevelopedtoforecasttheshapeevolutionoftubebilletsduringthesprayformingprocess.Theatomizermassfluxas,radialdistributioncoefficientbs,drawvelocityanddiameterofmandrelwereconsideredinthismodelandtheinfluenceofdifferentparameterssuchasmetalflowrate,drawvelocityofmandrel,diameterofmandrelonthetube'sshapechangeweresimulatedandanalyzedinthispaper.Thesimulationresultsobtainedfromthismodelcanbeprovidedtoengineersasreference.

简介：Springbackisconsideredtobeoneofthemostimportantproblemsinaluminumsheetstampforming,leadingtodeviationfromthedesignedtargetshapeandassemblydefects.Inthisstudy,aspringbacksimulationmodelbasedonthebenchmarkofaJaguarLandRoveraluminumpanelisestablished.Weembedseveralelastoplasticconstitutivemodels(Barlat's89,Barlat'sYLD2000,Yoshida-Uemori(YU)+Barlat's89,andYU+Barlat'sYLD2000)inthefiniteelementmodel,inordertodiscusstheinfluenceoftheconstitutivemodelselectiononspringbackpredictioninaluminumsheetforming.

简介：Thetensilebehaviorandpropertiesofcoldformedlow-carbonmicroalloyedsteelwithitsmicrostructureofallferriteandpearlite(F+P)wereinvestigated.Bendingandflatteningdeformationswerecarriedoutinthelaboratoryonhot-rolledsheetsinordertosimulatethecoldformingprocessofsteelsheetsduringpipefabricationandsamplingofhighfrequencystraightbeadweldingpipes.Acomparisonofthetensilebehaviorandpropertiesofthematerialmadebeforeandaftercoldformingindicatesthatcolddeformationaltersthetensilebehaviorandpropertiesofthematerialtoacertaindegreedependingonthemannerofthecolddeformationandthedegree.TheresearchontheBauschingereffectindicatesthatforthesteelsinvestigated,whentheplasticstrainissmall,thebackstressincreasesrapidlywiththeincreaseoftheplasticstrainandthenrapidlytendstosaturation.ThefiniteelementanalysisindicatesthatthechangeinthepropertiesofthesteelsheetsduetocoldformingisaresultoftheBauschingereffectandworkhardening.Themechanismofthechangeinthepropertiesisalsogiveninthisstudy.

简介：BasedontheABAQUSexplicitdynamicsimulationplatform,thefiniteelementmodelofsinglestandmillwithrestrainedmandrelwasadoptedtoresearchtheinfluenceofmandrel-rollervelocityratio(MRVR),mandrelfrictionandtensionbetweenstandsonrollingforce.TheanalysisresultsshowthatwhentheMRVRislowerthan1,therollingforceincreasesobviouslywiththeincreaseofMRVRandreachesthepeakvaluewhentheMRVRisabout1.TherollingforceincreaseinducedbytheMRVRincreaseisthemainreasonoftheformationofthebulgedefectonthetubeheadandtailattheenteringandexitingstageduringtubecontinuousrollingprocessbyfullfloatingmandrelmill,whichcanbeintensifiedbytheincreaseofmandrelfrictioncoefficient.Therollingforcedecreaseswiththeincreaseoftension.Asthetensionislarger,therollingforcedecreaseamplitudeislarger.Theinfluenceofbackwardtensiononrollingforceisgreaterthanthatofforwardtensiondistinctly.TensioncontrolcanbeusedtodecreasetherollingforceincreaseinducedbytheMRVRincrease,whichisimposingtensionatthesametimewhentheMRVRincreases,inordertoimproveeveneliminatethebulgedefect,andenhancethetubedimensionprecision.