【英文标准名称】:StandardTestMethodforImpactResistanceofFlat,RigidPlasticSpecimensbyMeansofaFallingDart(TuporFallingMass)
【原文标准名称】:用下落投掷法(冲击锤或下落块)测试扁平硬质塑料试样抗冲击性的标准试验方法
【标准号】:ASTMD5628-2010
【标准状态】:现行
【国别】:
【发布日期】:2010
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D20.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:镖冲击;下落块;冲击;抗冲击;平均破坏能量;平均破坏高度;平均破坏质量;硬质塑料;锤;镖冲击法;自由下落镖方法;冲击测试-塑料;平均破坏能量/高度/重量;锤(落锤);
【英文主题词】:dartimpact;falling-massimpact;impact;impactresistance;mean-failureenergy;mean-failureheight;mean-failuremass;rigidplastic;tup;Dartimpactmethod;Free-fallingdartmethod;Impacttesting--plastics;Mean-failureenergy/height/weight;
【摘要】:Plasticsareviscoelasticandthereforearelikelytobesensitivetochangesinvelocityofthemassfallingontheirsurfaces.However,thevelocityofafree-fallingobjectisafunctionofthesquarerootofthedropheight.Achangeofafactoroftwointhedropheightwillcauseachangeofonly1.4invelocity.Haganetal(2)foundthatthemean-failureenergyofsheetingwasconstantatdropheightsbetween0.30and1.4m.Thissuggeststhataconstantmass-variableheightmethodwillgivethesameresultsastheconstantheight-variablemasstechnique.Ontheotherhand,differentmaterialsresponddifferentlytochangesinthevelocityofimpact.Equivalenceofthesemethodsshouldnotbetakenforgranted.Whilebothconstant-massandconstant-heighttechniquesarepermittedbythesemethods,theconstant-heightmethodshouldbeusedforthosematerialsthatarefoundtoberate-sensitiveintherangeofvelocitiesencounteredinfalling-weighttypesofimpacttests.ThetestgeometryFAcausesamoderatelevelofstressconcentrationandcanbeusedformostplastics.GeometryFBcausesagreaterstressconcentrationandresultsinfailureoftoughorthickspecimensthatdonotfailwithGeometryFA(3).Thisapproachcanproduceapunchshearfailureonthicksheet.Ifthattypeoffailureisundesirable,GeometryFCshouldbeused.GeometryFBissuitableforresearchanddevelopmentbecauseofthesmallertestarearequired.Theconicalconfigurationofthe12.7-mmdiametertupusedinGeometryFBminimizesproblemswithtuppenetrationandstickinginfailedspecimensofsomeductilematerials.ThetestconditionsofGeometryFCarethesameasthoseofTestMethodAofTestMethodD1709.Theyhavebeenusedinspecificationsforextrudedsheeting.Alimitationofthisgeometryisthatconsiderablematerialisrequired.ThetestconditionsofGeometryFDarethesameasforTestMethodD3763.ThetestconditionsofGeometryFEarethesameasforISO6603-1.Becauseofthenatureofimpacttesting,theselectionofatestmethodandtupmustbesomewhatarbitrary.Althoughachoiceoftupgeometriesisavailable,knowledgeofthefinalorintendedend-useapplicationshallbeconsidered.Clampingofthetestspecimenwillimprovetheprecisionofthedata.Therefore,clampingisrecommended.However,withrigidspecimens,validdeterminationscanbemadewithoutclamping.Unclampedspecimenstendtoexhibitgreaterimpactresistance.Beforeproceedingwiththistestmethod,referenceshouldbemadetothespecificationofthematerialbeingtested.Table1ofClassificationSystemD4000liststheASTMmaterialsstandardsthatcurrentlyexist.Anytestspecimenspreparation,conditioning,dimensions,ortestingparametersorcombinationthereofcoveredintherelevantASTMmaterialsspecificationshalltakeprecedenceoverthosementionedinthistestmethod.IftherearenorelevantASTMmaterialspecifications,thenthedefaultconditionsapply.1.1Thistestmethodcoversthedeterminationofthethresholdvalueofimpact-failureenergyrequiredtocrackorbreakflat,rigidplasticspecimensundervariousspecifiedconditionsofimpactofafree-fallingdart(tup),basedontestingmanyspecimens.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesinparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibi......
【中国标准分类号】:G31
【国际标准分类号】:83_140_10
【页数】:10P.;A4
【正文语种】: