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【英文标准名称】:StandardTestMethodforUltimateStrengthofAdvancedCeramicswithDiametrallyCompressedC-RingSpecimensatAmbientTemperature
【原文标准名称】:环境温度下径向压缩C环样品的高级陶瓷的极限强度的标准试验方法
【标准号】:ASTMC1323-2010
【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】:C28.04
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:advancedceramic;C-ringspecimen;uniaxialstrength;Advancedceramics;C-ringspecimens;Monotoniccompressivestrength;Strength--ceramicmaterials/applications;Ultimatestrength
【摘要】:Thistestmethodmaybeusedformaterialdevelopment,materialcomparison,qualityassurance,andcharacterization.Extremecareshouldbeexercisedwhengeneratingdesigndata.ForaC-ringunderdiametralcompression,themaximumtensilestressoccursattheoutersurface.Hence,theC-ringspecimenloadedincompressionwillpredominatelyevaluatethestrengthdistributionandflawpopulation(s)ontheexternalsurfaceofatubularcomponent.Accordingly,theconditionoftheinnersurfacemaybeoflesserconsequenceinspecimenpreparationandtesting.Note18212;AC-ringintensionoranO-ringincompressionmaybeusedtoevaluatetheinternalsurface.Theflexurestressiscomputedbasedonsimplecurved-beamtheory(1,2,3,4,5).Itisassumedthatthematerialisisotropicandhomogeneous,themoduliofelasticityareidenticalincompressionortension,andthematerialislinearlyelastic.Thesehomogeneityandisotropyassumptionsprecludetheuseofthisstandardforcontinuousfiberreinforcedcomposites.Averagegrainsize(s)shouldbenogreaterthanonefiftieth(1/50)oftheC-ringthickness.Thesimplecurved-beamtheorystresssolutionisingoodagreement(typicallybetterthan1%)withatheoryofelasticitysolutionasdiscussedin(3)forthegeometrieschosenforthisstandard.Thesimplebeamtheorystressequationsarerelativelysimple.TheyarerelativelyeasytointegrateforWeibulleffectivevolumeoreffectiveareacomputationsasshowninAppendixX1.Thesimplecurvedbeamandtheoryofelasticitystresssolutionsbotharetwo-dimensionalplanestresssolutions.Theydonotaccountforstressesintheaxial(paralleltob)direction,orvariationsinthecircumferential(hoop,x03C3;x03B8;)stressesthroughthewidth(b)ofthetestpiece.Thevariationsinthecircumferentialstressesincreasewithincreasesinwidth(b)andringthickness(t).Thevariationscanbesubstantial(>10%)fortestspecimenswithlargeb.Thecircumferentialstressespeakattheouteredges.Therefore,thewidth(b)andthickness(t)ofthespecimenspermittedinthistestmethodarelimitedsothataxialstressesarenegligible(seeRef.5)andthevariationsofthecircumferentialstressesfromthenominalsimplecurvedbeamtheorystresscalculationsaretypicallylessthan4%.SeeRef.(3)and(4)formoreinformationonthevariationofthecircumferentialstressesasafunctionofringthickness(t)andringwidth(b).Thetestpieceouterrimcornersarevulnerabletoedgedamage,anotherreasontominimizethedifferencesinthecircumferentialstressesacrosstheringoutersurface.OthergeometryCx2013;ringtestspecimensmaybetested,butcomprehensivefiniteelementanalysesshallbeperformedtoobtainaccuratestressdistributions.Ifstrengthsaretobescaled(converted)tostrengthsofothersizesorgeometries,thenWeibulleffectivevolumesorareasshallbecomputedusingtheresultsofthefiniteelementanalyses.Becauseadvancedceramicsexhibitingbrittlebehaviorgenerallyfracturecatastrophicallyfromasingledominantflawforaparticulartensilestressfield,thesurfaceareaandvolumeofmaterialsubjectedtotensilestressesisasignificantfactorindeterminingtheultimatestrength.Moreover,becauseofthestatisticaldistributionoftheflawpopulation(s)inadvancedceramicsexhibitingbrittlebehavior,asufficientn..........
【中国标准分类号】:Q32
【国际标准分类号】:81_060_99
【页数】:8P.;A4
【正文语种】:英语