ASTM D747-2002 用悬臂梁法对塑料表观弯曲系数的标准试验方法

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【英文标准名称】:StandardTestMethodforApparentBendingModulusofPlasticsbyMeansofaCantileverBeam
【原文标准名称】:用悬臂梁法对塑料表观弯曲系数的标准试验方法
【标准号】:ASTMD747-2002
【标准状态】:现行
【国别】:
【发布日期】:2002
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:D20.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:试验;塑料
【英文主题词】:apparentbendingmodulus;bendingmovement;cantileverbeam;stiffness;
【摘要】:Thistestmethodprovidesameansofderivingtheapparentbendingmodulusofamaterialbymeasuringforceandangleofbendofacantileverbeam.Themathematicalderivationassumessmalldeflectionsandpurelyelasticbehavior.Underactualtestconditions,thedeformationhasbothelasticandplasticcomponents.Thistestmethoddoesnotdistinguishorseparatethese,andhenceatrueelasticmodulusisnotcalculable.Instead,anapparentvalueisobtainedandisdefinedastheapparentbendingmodulusofthematerial.ThetangentmodulusobtainedbyTestMethodsD790ispreferred,whenthematerialcanbetestedbytheTestMethodsD790testprocedure.Becauseofdeviationsfrompurelyelasticbehavior,changesinspanlength,width,anddepthofthespecimenwillaffectthevalueoftheapparentbendingmodulusobtained;therefore,valuesobtainedfromspecimensofdifferentdimensionsmaynotnecessarilybecomparable.Rateofloadingiscontrolledonlytotheextentthattherateofangularchangeoftherotatingjawisfixedat58to66x00B0;/min.Actualrateofstressingwillbeaffectedbyspanlength,width,depthofthespecimen,andweightofthependulum.Formanymaterials,theremaybeaspecificationthatrequirestheuseofthistestmethod,butwithsomeproceduralmodificationsthattakeprecedencewhenadheringtothespecification.Therefore,itisadvisabletorefertothatmaterialspecificationbeforeusingthistestmethod.Table1ofClassificationSystemD4000liststheASTMmaterialsstandardsthatcurrentlyexist.Note28212;Adiscussionofthetheoryofobtainingapurelyelasticbendingmodulus,usingacantileverbeamtestingapparatus,canbefoundinAppendixX1.Theresultsobtainedunderactualtestconditionswillbetheapparentbendingmodulus.1.1Thistestmethodcoversthedeterminationoftheapparentbendingmodulusofplasticsbymeansofacantileverbeam.Itiswellsuitedfordeterminingrelativeflexibilityofmaterialsoverawiderange.ItisparticularlyusefulformaterialstooflexibletobetestedbyTestMethodsD790.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note18212;ThereisnoknownISOequivalentforthisstandard.
【中国标准分类号】:G31
【国际标准分类号】:83_080_01
【页数】:5P.;A4
【正文语种】: