VDA238-100-中英对照版

VDA–xxx(Prüfblatt)/VDAxxx(term)August2010/August2010Plättchen-BiegeversuchfürmetallischeHalbzeugePlatebendingtestformetallicsemi-finishedmaterialsVDA238-xxxFortsetzungSeite2bis13Continuedpage2topage13VERBANDDERAUTOMOBILINDUSTRIEE.V.(VDA)Behrenstr.3510117BerlinVertrieb:DOKUMENTATIONKRAFTFAHRTWESENE.V.(DKF)Ulrichstraße14,D-74321Bietigheim-Bissingen,此测试规范描述了如何执行板材弯曲测试和确定弯曲角度。弯曲测试用于得出金属材料在弯曲变形为主导的加工过程（例如折弯操作）中，或者在冲击载荷作用下，有关成型过程和失效敏感性的一些结论。Thistestspecificationdescribeshowtoperformtheplatebendingtestandhowtodeterminethebend-ingangle.Thetestsareintendedtodrawconclu-sionsabouttheformingbehaviorandthesuscepti-bilitytofailureofmetallicmaterialsduringformingprocesseswithdominantbendingportions(e.g.hemmingoperations)orduringcrashloads.2适用范围2Scope本试验规范适用于改良对金属材料样品进行的弯曲试验，例如高强度钢，铝合金或镁合金。Thistestspecificationappliestothemodifiedplatebendingtestonmetallicspecimenslikehigh-strengthsteel,aluminum-ormagnesium-alloys.3缩略语3AbbreviationsF试验力，单位为NS下压距离，单位为mmD支辊直径，单位为mmL支辊距离，单位为mmR支辊半径，单位为mma样品厚度，单位为mmb样品宽度，单位为mml样品长度，单位为mmr冲头半径，单位为mm弯曲角度，单位为°Rm抗拉强度，单位为MPaFPunchforceinNSPunchdisplacementinmmDRollerdiameterinmmLRollerdistanceinmmRRollerradiusinmmaSamplethicknessinmmbSamplewidthinmmlSamplelengthinmmrPunchradiusinmmBendinganglein°RmTensilestrengthinMPa4测试设备4TestEquipment配备弯曲装置的万能试验机配备低摩擦安装的支辊的弯曲装置（图1）弯曲冲头（图2）角度测量装置UniversaltestingmachinewithsupportforthebendingdeviceBendingdevicewithlow-frictionmountedrollersupports(Figure1)Bendingpunch(Figure2)Anglemeasuringdevice5样品5SamplesSeite/Page2VDAxxxAugust2010/VDAxxxAugust20105.1试样制备5.1SamplePreparation5.1.1常规制备5.1.1GeneralPreparation平板试样的尺寸应该为60mm×60mm。如果所需的试样尺寸无法实现，在客户事先允许的情况下，试样宽度可以减小。为了最小化试样边缘区域三角应力状态的影响，目前宽度必须超过样品厚度。最佳情况是试样宽度b≥20*样品厚度a。测试机构和客户之间可以通过递交相关规范或者类似的文件，就试样最小宽度可以达成一致。可能存在的防腐蚀油层或其他涂层必须从试样表面去除。在弯曲测试过程中，测试的值仅应在裂纹源不在边缘范围形成的情况下被使用。这点必须从材料上保证，通过使用轧齿边，研磨或去毛刺的方法，对边缘进行再加工。Thedimensionsoftheplainspecimensshallbe60mmx60mm.Thespecimenwidthcanbereducedafterpriorapprovalbythecustomer,iftherequiredspecimendimensionscannotberealized.Inordertominimizetheinfluenceofthethree-axesstressconditionintheareaoftheedgesthespecimenwidthmustexceedthesamplethicknessbyfar.Preferablythespecimenwidthshouldbeb≥20*samplethicknessa.Aminimumwidthcanbeagreedbetweenthetestinginstituteandthecustomerbymeansofdeliveryspecificationsorthelike.Probablyexistingcorrosionprotectionoilsordrawingaidsmustberemovedfromthespecimensurface.Themeasuredvaluesshallbeusedonlyifthecrackformationduringthebendingtestisnotinitiatedwithintheedges.Thismustbeensured,independenceofthematerial,byreworkingtheedgesbymeansofmilling,grindingordeburring.5.1.2制备用于测定弯曲性和折叠性的样品5.1.2Preparationofsamplesforthedeterminationofbendabilityandfoldability当以供应状态进行测试时，具有高成形潜力的材料（例如身体外部皮肤的特性）可以在弯曲测试中弯曲几乎180°而不失效。这些材料可以在弯曲试验之前单轴预应变，以便更好地表征弯曲性和抗折强度。测试使用了长度为250mm，宽度为70mm的片状金属带材进行试验，每个样品根据主（弯曲）应变方向从产品中取出。因此，预应变垂直于弯曲线的取向施加。预应变参数取自表1。预应变和弯曲之间的不同应变方向必须排除。可以从预应后的片状金属带材的中心区域取出尺寸为60mmx60mm的两个弯曲试样。假定试样内的应变均匀分布。如果不能实现上述试样尺寸，可能产生误差。这必须与客户达成一致。Whentestedintheas-suppliedconditionmaterialswithhighformingpotential(e.g.bodyexteriorskinqualities)canbebentinthebendingtestbyalmost180°withoutfailure.Thesematerialsmaybepre-straineduniaxiallybeforethebendingtestinordertoachieveabettercharacterizationofthebendabilityandhemmability.Thetestisperformedonsheetmetalstripswithalengthof250mmandawidthof70mm,eachtakenfromtheproductaccordingtothelatermain(bending)straindirection.Thus,thepre-strainisappliedverticallytotheorientationofthebendingline.Thepre-strainparametersaretobetakenfromTable1.Differentstraindirectionsbetweenpre-strainandbendingmustbeexcluded.Twobendingspecimenswithdimensions60mmx60mmcanbetakenfromthecenterareaofthepre-strainedsheetmetalstrip.Ahomogeneousstraindistributionwithinthespecimensisassumed.Ifabovespecimendimensioncannotberealizedadeviationispossible.Thismustbeagreedwiththecustomerhowever.参数/Parameter值/Value样品尺寸(长度x宽度)Samplesize(lengthxwidth)250mmx70mm预应变/Prestraining:Al-板材/Al-sheetAl-挤压型材/Alextrusionprofil钢板/steelsheet(Rm580MPa)10%5%15%5%Seite/Page3VDAxxxAugust2010/VDAxxxAugust2010钢板/steelsheet(Rm≥580MPa)预应变速率Prestrainingrate25mm/min夹子之间的自由长度Freelengthbetweenclamps150mm表1:预应变参数Table1:Prestrainingparameters从预应变带材中取样的过程与上述方法相同。如果组件几何形状要求，可能会偏离预应变方向。Theprocessfortakingsamplesfromthepre-strainedstripeisthesameasalreadydescribedabove.Ifthecomponentgeometryrequiresso,adeviationfromthepre-strainingdirectionispossible.5.2样品名称5.2Sampledesignation为了清楚地分配一个测试样本名称/条件，采样必须符合下述规范（特性）。特性要用下划线（“_”）分隔。如果确保了所需的清楚和明确的分配，则允许根据测试机构的内部指南进行样品命名。如果使用了内部命名条例，则必须对其进行记录并将其提供给客户。除了测试结果和评估方法外，每个测试系列必须记录以下编号1至10的特征。Inordertoclearlyallocateatesttoasampledesignation/condition,sampletakingmustcomplywiththespecifications(characteristics)describedbelow.Characteristicsaretobeseparatedbyun-derscore(„_“).Sampledesignationsaccordingtointernalguidelinesofthetestinginstitutesareper-mittediftherequiredclearandunambiguousalloca-tionisensured.Ifinternalnamingconventionsareusedthesemustbedocumentedandmadeavaila-bletothecustomer..Inadditiontothetestingresultsandtheevaluationmethod