ASTM D256-2010 测定塑料的耐悬臂梁摆锤撞击性能的标准试验方法

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【英文标准名称】:StandardTestMethodsforDeterminingtheIzodPendulumImpactResistanceofPlastics
【原文标准名称】:测定塑料的耐悬臂梁摆锤撞击性能的标准试验方法
【标准号】:ASTMD256-2010
【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】:impactresistance;Izodimpact;notchsensitivity;notchedspecimen;reversenotchimpact;Pendulumtest;Cantilevertesting;Charpyimpacttest;Electricalinsulatingsolids;Impactresistance;Impactresistance--plastics;Impacttesting--Charpy;Imp
【摘要】:Beforeproceedingwiththesetestmethods,referenceshouldbemadetothespecificationofthematerialbeingtested.Anytestspecimenpreparation,conditioning,dimensions,andtestingparameterscoveredinthematerialsspecificationshalltakeprecedenceoverthosementionedinthesetestmethods.Ifthereisnomaterialspecification,thenthedefaultconditionsapply.Thependulumimpacttestindicatestheenergytobreakstandardtestspecimensofspecifiedsizeunderstipulatedparametersofspecimenmounting,notching,andpendulumvelocity-at-impact.Theenergylostbythependulumduringthebreakageofthespecimenisthesumofthefollowing:Energytoinitiatefractureofthespecimen;Energytopropagatethefractureacrossthespecimen;Energytothrowthefreeend(orends)ofthebrokenspecimen(x201C;tosscorrectionx201D;);Energytobendthespecimen;Energytoproducevibrationinthependulumarm;Energytoproducevibrationorhorizontalmovementofthemachineframeorbase;Energytoovercomefrictioninthependulumbearingandintheindicatingmechanism,andtoovercomewindage(pendulumairdrag);Energytoindentordeformplasticallythespecimenatthelineofimpact;andEnergytoovercomethefrictioncausedbytherubbingofthestriker(orotherpartofthependulum)overthefaceofthebentspecimen.Forrelativelybrittlematerials,forwhichfracturepropagationenergyissmallincomparisonwiththefractureinitiationenergy,theindicatedimpactenergyabsorbedis,forallpracticalpurposes,thesumoffactors5.3.1and5.3.3.Thetosscorrection(see5.3.3)mayrepresentaverylargefractionofthetotalenergyabsorbedwhentestingrelativelydenseandbrittlematerials.TestMethodCshallbeusedformaterialsthathaveanIzodimpactresistanceoflessthan27J/m(0.5ftx00B7;lbf/in.).(SeeAppendixX4foroptionalunits.)ThetosscorrectionobtainedinTestMethodCisonlyanapproximationofthetosserror,sincetherotationalandrectilinearvelocitiesmaynotbethesameduringthere-tossofthespecimenasfortheoriginaltoss,andbecausestoredstressesinthespecimenmayhavebeenreleasedaskineticenergyduringthespecimenfracture.Fortough,ductile,fiberfilled,orcloth-laminatedmaterials,thefracturepropagationenergy(see5.3.2)maybelargecomparedtothefractureinitiationenergy(see5.3.1).Whentestingthesematerials,factors(see5.3.2,5.3.5,and5.3.9)canbecomequitesignificant,evenwhenthespecimenisaccuratelymachinedandpositionedandthemachineisingoodconditionwithadequatecapacity.(SeeNote7.)Bending(see5.3.4)andindentationlosses(see5.3.8)maybeappreciablewhentestingsoftmaterials.Note78212;Althoughtheframeandbaseofthemachineshouldbesufficientlyrigidandmassivetohandletheenergiesoftoughspecimenswithoutmotionorexcessivevibration,thedesignmustensurethatthecenterofpercussionbeatthecenterofstrike.Locatingthestrikerpreciselyatthecenterofpercussionreducesvibrationofthependulumarmwhenusedwithbrittlespecimens.However,somelossesduetopendulumarmvibration,theamountvaryingwiththedesignofthependulum,willoccurwithtoughspecimens,evenwhenthestrikerisproperlypositioned.Inawell-designedmachineofsufficientrigidityandmass,thelossesduetofactors5.3.6and5.3.7shouldbeverysmall.Vibrationallosses(see5.3.6)canbequitelargewhenwidespecimensoftoughmaterialsaretestedinmachinesofinsufficientmass,notsecurelyfastenedtoaheavybase.Withsomematerials,acriticalwidthofspecimenmaybefoundbelowwhichspecimen..........
【中国标准分类号】:G31
【国际标准分类号】:29_035_20
【页数】:20P.;A4
【正文语种】:英语