ANSI/ASTM D256-1993 塑料及电绝缘材料抗冲击性试验方法

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【英文标准名称】:TestMethodsforImpactResistanceofPlasticsandElectricalInsulatingMaterials(08.01,09.02)
【原文标准名称】:塑料及电绝缘材料抗冲击性试验方法
【标准号】:ANSI/ASTMD256-1993
【标准状态】:现行
【国别】:美国
【发布日期】:1993
【实施或试行日期】:
【发布单位】:美国国家标准学会(US-ANSI)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:电绝缘材料;塑料;试验;冲击强度
【英文主题词】:impactstrength;electricalinsulatingmaterials;testing;plastics
【摘要】:Thesetestmethodscoverthedeterminationoftheresistanceofplasticsto"standardized"(seeNote0)pendulum-typehammers,mountedin"standardized"machines,inbreakingstandardspecimenswithonependulumswing(seeNote0).Thestandardtestsforthesetestmethodsrequirespecimensmadewithamillednotch(seeNote0).InTestMethodsA,C,andD,thenotchproducesastressconcentrationthatincreasestheprobabilityofabrittle,ratherthanaductile,fracture.InTestMethodE,theimpactresistanceisobtainedbreakagebyflexuralshockasindicatedbytheenergyextractedfrombyreversingthenotchedspecimen180intheclampingvise.Theresultsofalltestmethodsarereportedintermsofenergyabsorbedperunitofspecimenwidthorperunitofcross-sectionalareaunderthenotch.(SeeNote0.)Note0Themachineswiththeirpendulum-typehammershavebeen"standardized"inthattheymustcomplywithcertainrequirements,includingafixedheightofhammerfallthatresultsinasubstantiallyfixedvelocityofthehammeratthemomentofimpact.However,hammersofdifferentinitialenergies(producedbyvaryingtheireffectiveweights)arerecommendedforusewithspecimensofdifferentimpactresistance.Moreover,manufacturersoftheequipmentarepermittedtousedifferentlengthsandconstructionsofpendulumswithpossibledifferencesinpendulumrigiditiesresulting.(SeeSection.)Beawarethatotherdifferencesinmachinedesignmayexist.Thespecimensare"standardized"inthattheyarerequiredtohaveonefixedlength,onefixeddepth,andoneparticulardesignofmillednotch.Thewidthofthespecimensispermittedtovarybetweenlimits.Note0Resultsgeneratedusingpendulumsthatutilizealoadcelltorecordtheimpactforceandthusimpactenergy,maynotbeequivalenttoresultsthataregeneratedusingmanuallyordigitallyencodedtestersthatmeasuretheenergyremaininginthependulumafterimpact.Note0ThenotchintheIzodspecimenservestoconcentratethestress,minimizeplasticdeformation,anddirectthefracturetothepartofthespecimenbehindthenotch.Scatterinenergy-to-breakisthusreduced.However,becauseofdifferencesintheelasticandviscoelasticpropertiesofplastics,responsetoagivennotchvariesamongmaterials.Ameasureofaplastic's"notchsensitivity"maybeobtainedwithTestMethodDbycomparingtheenergiestobreakspecimenshavingdifferentradiiatthebaseofthenotch.Note0Cautionmustbeexercisedininterpretingtheresultsofthesestandardtestmethods.Thefollowingtestingparametersmayaffecttestresultssignificantly:Methodoffabrication,includingbutnotlimitedtoprocessingtechnology,moldingconditions,molddesign,andthermaltreatments;Methodofnotching;Speedofnotchingtool;Designofnotchingapparatus;Qualityofthenotch;Timebetweennotchingandtest;Testspecimenthickness,Testspecimenwidthundernotch,andEnvironmentalconditioning.ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninbracketsareforinformationonly.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.ThesetestmethodsresembleISO180:1993inregardtotitleonly.Thecontentsaresignificantlydifferent.
【中国标准分类号】:K15
【国际标准分类号】:29_035_20
【页数】:
【正文语种】:英语