ASTM D638-2010 塑料的拉伸性能的标准试验方法

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【英文标准名称】:StandardTestMethodforTensilePropertiesofPlastics
【原文标准名称】:塑料的拉伸性能的标准试验方法
【标准号】:ASTMD638-2010
【标准状态】:现行
【国别】:美国
【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】:
【英文主题词】:modulusofelasticity;percentelongation;plastics;tensileproperties;tensilestrength;Engineeringcriteria/design;Reinforcedplastics;Tensileproperties/testing--plastics;Unreinforcedplastics
【摘要】:Thistestmethodisdesignedtoproducetensilepropertydataforthecontrolandspecificationofplasticmaterials.Thesedataarealsousefulforqualitativecharacterizationandforresearchanddevelopment.Formanymaterials,theremaybeaspecificationthatrequirestheuseofthistestmethod,butwithsomeproceduralmodificationsthattakeprecedencewhenadheringtothespecification.Therefore,itisadvisabletorefertothatmaterialspecificationbeforeusingthistestmethod.Table1inClassificationD4000liststheASTMmaterialsstandardsthatcurrentlyexist.Tensilepropertiesmayvarywithspecimenpreparationandwithspeedandenvironmentoftesting.Consequently,whereprecisecomparativeresultsaredesired,thesefactorsmustbecarefullycontrolled.Itisrealizedthatamaterialcannotbetestedwithoutalsotestingthemethodofpreparationofthatmaterial.Hence,whencomparativetestsofmaterialspersearedesired,thegreatestcaremustbeexercisedtoensurethatallsamplesarepreparedinexactlythesameway,unlessthetestistoincludetheeffectsofsamplepreparation.Similarly,forrefereepurposesorcomparisonswithinanygivenseriesofspecimens,caremustbetakentosecurethemaximumdegreeofuniformityindetailsofpreparation,treatment,andhandling.Tensilepropertiesmayprovideusefuldataforplasticsengineeringdesignpurposes.However,becauseofthehighdegreeofsensitivityexhibitedbymanyplasticstorateofstrainingandenvironmentalconditions,dataobtainedbythistestmethodcannotbeconsideredvalidforapplicationsinvolvingload-timescalesorenvironmentswidelydifferentfromthoseofthistestmethod.Incasesofsuchdissimilarity,noreliableestimationofthelimitofusefulnesscanbemadeformostplastics.Thissensitivitytorateofstrainingandenvironmentnecessitatestestingoverabroadload-timescale(includingimpactandcreep)andrangeofenvironmentalconditionsiftensilepropertiesaretosufficeforengineeringdesignpurposes.Note58212;Sincetheexistenceofatrueelasticlimitinplastics(asinmanyotherorganicmaterialsandinmanymetals)isdebatable,theproprietyofapplyingthetermx201C;elasticmodulusx201D;initsquoted,generallyaccepteddefinitiontodescribethex201C;stiffnessx201D;orx201C;rigidityx201D;ofaplastichasbeenseriouslyquestioned.Theexactstress-straincharacteristicsofplasticmaterialsarehighlydependentonsuchfactorsasrateofapplicationofstress,temperature,previoushistoryofspecimen,etc.However,stress-straincurvesforplastics,determinedasdescribedinthistestmethod,almostalwaysshowalinearregionatlowstresses,andastraightlinedrawntangenttothisportionofthecurvepermitscalculationofanelasticmodulusoftheusuallydefinedtype.Suchaconstantisusefulifitsarbitrarynatureanddependenceontime,temperature,andsimilarfactorsarerealized.1.1Thistestmethodcoversthedeterminationofthetensilepropertiesofunreinforcedandreinforcedplasticsintheformofstandarddumbbell-shapedtestspecimenswhentestedunderdefinedconditionsofpretreatment,temperature,humidity,andtestingmachinespeed.1.2Thistestmethodcanbeusedfortestingmaterialsofanythicknessupto14mm(0.55in.).However,fortestingspecimensintheformofthinsheeting,includingfilmlessthan1.0mm(0.04in.)inthickness,TestMethods