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2.Makesuretheimageisbehindallobjectsonthepage.Text/colorbars/colorboxes/logos3.DELETETHESEINSTRUCTIONBOXWHENDONE2.Makesuretheimageisbehindallobjectsonthepage.Text/colorbars/colorboxes/logos3.DELETETHESEINSTRUCTIONBOXWHENDONE•October2012FinancialsAutomotiveVS•NovelisAutomiveEuropeMichaelHöhnkeTechnicalSeminarB.GeneraldesignrecommendationsforAluminiumSGM-NovelisB.DesignB.1GeneraldesignrecommendationsGeneralconsiderationsIfpurestrengthisneededsteelIfstiffnessisneededAlcanfightwithsteelbycompensatingwiththicknessandstillsavingweightDependingonapplicationsacompromisebetweenstiffnessandstrengthhastobefound.balancebetweenextracostvs.weightsaving:whatisaffordable?BIWstructureDesigncriterionComparisonofAl&SteelBasicproperties0.0010.0020.0030.0040.0050.0060.0070.001.01.21.41.61.82.02.22.42.62.83.0%WeightReductionAluminiumUpgaugeFactorFWeightReductionasaFunctionofUpgaugeFactorChangandJustussonSAEPaper760023,1976Baseduponmildsteelandaluminiumwithanin-servicestrengthof207MPaComparisonofbasicmaterialpropertiesDensity:rAl=1/3rsteel•Reducedmass&lighterweightvehiclesElasticmodulus:EAl=1/3Esteel•Greaterelasticdeflectioncomparedtosteel•Equivalentperformanceatanapproximateupgaugeof70%•Anup-gaugeof80%willgiveaweightsavingof40%Aluminiumhasgenerallyareducedformabilitycomparedtosteel•Elongation•Flanging•FLDPerformancealuminiumPanel/mildsteelpanelThicknessratiotalu/tsteBIWStructure:CriterionOuters/Closureparts:CriterionStiffness-FlatSheetEt2orEt3Stiffness-SheetEt2orEt3Stiffness–BIWE[(D+t)3-D3]StrengthRpTorsion-BIWE[(r+t)4-r4]BucklingEt3StrengthRpDentResistanceRpt1.8BucklingLoadElastEt3BucklingLoadPlastE0.43t1.86D0.14YS0.57Av.CrashLoad,CrushAv.FSt1.8D0.2Max.CrashLoad,BendE0.43t1.86D0.14YS0.57Strengthhasnoinfluenceonthestiffnessofapart!Onlygaugeordesigncaninfluencethestiffnessofanaluminiumpart.BodyinWhitedesignAnalyticandEmpiricalformulaegoverningmainperformancecriterionChangandJustussonSAEPaper760023,1976Baseduponmildsteelandaluminiumwithanin-servicestrengthof207MPaEt2Et3Chang&JustussonSAEPaper760023,1976Baseduponmildsteel&Aluminium,bothwithanin-serviceProofStressof207MPa•Twocriterionexist:–Stiffness-FlatSheetEt2associatedwith“Oilcanning”–Stiffness-FlatSheetEt3associatedwithsheetbucklingorbending•OilCanningresistancerequiresa70%upgaugetogiveequivalentsteelperformancewithacorresponding43%masssaving•Sheetbucklingresistancerequiresa45%upgaugetogiveequivalentsteelperformancewithacorresponding52%masssaving•Note:ProofStressorUTShasnoinfluenceonsheetstiffnessproperties–AluminiumeasilysatisfiesthestiffnesstargetwithagoodmasssavingcomparedtoanysteelgradeBIWStructure–DesignCriterionforStiffnessNominallyFlatSheetTwodifferentcriterionexist:Stiffness=bendingdeflection(E[(D+t)3-D3])Stiffness=Torsionangularrotational(G[(r+t)4-r4])WhereGistheModulusofRigidityForsamesizeofboxsection,aluminiumwillrequirea186%up-gaugecomparedtosteeltogivethesamebendingbehaviourThiswillresultinnomasssavingcomparedtosteelAluminiumrequiresanincreasedboxsectionsizevssteeltosavemassA20%increaseinsectiondepthDrequiresa90%up-gauge,forequivalentsteelperfomance,givingamasssavingof25%DtBIWStructure–DesignCriterionforStiffnessBoxsectionsandtubes0501001502002503003504000.600.801.001.201.401.60InServiceProofStressMPaGaugemmAc6002%Strain+PBAc170PX2%Strain+PBAc120asreceivedAc1202%Strain+PBNote:KisafactordependinguponloadingandsupportmethodBasedonSteelProofstressof300MPa&gaugeof0.7mm•Itisfirstnecessarytosatisfypanelstiffness,(suitabledesignoftheinnerpanel,useoffeaturelines,etc.)•Ifpanelstiffnessisexceeded,thenpanelmaybedowngaugedonbasisoflocaldentability•Higherin-servicestrengthallowsreducedpanelgaugesOuterskinpanelsdesigncriterionStiffnessandlocaldentabilityLocalDentabilityforouterskins(In-serviceproofstressxgauge1.8)Flatpanelstiffness~E·t2or~E·t3Esteel200GPaEaluminium70GPaE=materialYoung’smodulust=gaugeofthepanelAluminiumpanelcancatchupstiffnessofsteelpanel:►byincreasingthegauge►bymodifyingthedesign(example:characterlines)6xxxaluminiumforautomotiveapplicationsStiffnessconsiderationsAluminiumpanelcancatchupstiffnessofsteelpanel:►byincreasingthegauge►bymodifyingthedesign(example:characterlines)StiffnessincreasebyfivetimescomparedtoflatpanelEffectonthestiffnessintroducedbytheasymmetricembossmentsAluminiumforautomotiveapplicationsStiffnessconsiderationsalsoforstructureandinnerpartsComparedto«pointjoining»,«linearjoining»increasesthestiffnessofassembledparts:MercedeesS-ClassmotorhoodLinearadhesivebondingforstiffeningBMW7doorframeLinearlaserweldingforstiffeningMercedesE-Classrearseatsbackwall:-Linearadhesivebondingforstiffening-CorrosionprotectioninhybridjoiningaluminiumsteelLinearjoiningincreasesstiffnessthrough«boxeffect»AluminiumforautomotiveapplicationsStiffnessconsiderationsalsoforstructureandinnerpartsAluminiumTechnologyDesignforHemFlangingReduceradiusreducegapbetween2partsProposedDoorHandlePocket...FinalDesign...GeneralrulesforstampedpanelsdesignPanelcurvature:►Limitdepth►OpenroundcornersFeatureadded@liftgateinnersealsurfaceInnerpanels:Avoidunsupportedmeta
本文标题:汽车设计与维修人员培训课件汽车的设计工艺
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