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【英文标准名称】:StandardTestMethodforMeasurementofFractureToughness
【原文标准名称】:断裂韧性测定的标准试验方法
【标准号】:ASTME1820-2009e1
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【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】:E08.07
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:crackinitiation;crack-tipopeningdisplacement;CTOD;ductilefracture;elastic-plasticfracturetoughness;fractureinstability;J-integral;KIc;plane-strainfracturetoughness;resistancecurve;stablecrackgrowth;Crack-tipope
【摘要】:Assumingthepresenceofapreexisting,sharp,fatiguecrack,thematerialfracturetoughnessvaluesidentifiedbythistestmethodcharacterizeitsresistanceto:(1)fractureofastationarycrack,(2)fractureaftersomestabletearing,(3)stabletearingonset,and(4)sustainedstabletearing.Thistestmethodisparticularlyusefulwhenthematerialresponsecannotbeanticipatedbeforethetest.ApplicationofproceduresinTestMethodE1921isrecommendedfortestingferriticsteelsthatundergocleavagefractureintheductile-to-brittletransition.Thesefracturetoughnessvaluesmayserveasabasisformaterialcomparison,selection,andqualityassurance.Fracturetoughnesscanbeusedtorankmaterialswithinasimilaryieldstrengthrange.Thesefracturetoughnessvaluesmayserveasabasisforstructuralflawtoleranceassessment.Awarenessofdifferencesthatmayexistbetweenlaboratorytestandfieldconditionsisrequiredtomakeproperflawtoleranceassessment.Thefollowingcautionarystatementsarebasedonsomeobservations.Particularcaremustbeexercisedinapplyingtostructuralflawtoleranceassessmentthefracturetoughnessvalueassociatedwithfractureaftersomestabletearinghasoccurred.Thisresponseischaracteristicofferriticsteelinthetransitionregime.Thisresponseisespeciallysensitivetomaterialinhomogeneityandtoconstraintvariationsthatmaybeinducedbyplanargeometry,thicknessdifferences,modeofloading,andstructuraldetails.TheJ-Rcurvefrombend-typespecimensrecommendedbythistestmethod(SE(B),C(T),andDC(T))hasbeenobservedtobeconservativewithrespecttoresultsfromtensileloadingconfigurations.Thevaluesofx03B4;c,x03B4;u,Jc,andJumaybeaffectedbyspecimendimensions.1.1Thistestmethodcoversproceduresandguidelinesforthedeterminationoffracturetoughnessofmetallicmaterialsusingthefollowingparameters:K,J,andCTOD(x03B4;).ToughnesscanbemeasuredintheR-curveformatorasapointvalue.Thefracturetoughnessdeterminedinaccordancewiththistestmethodisfortheopeningmode(ModeI)ofloading.1.2Therecommendedspecimensaresingle-edgebend,[SE(B)],compact,[C(T)],anddisk-shapedcompact,[DC(T)].Allspecimenscontainnotchesthataresharpenedwithfatiguecracks.1.2.1Specimendimensional(size)requirementsvaryaccordingtothefracturetoughnessanalysisapplied.Theguidelinesareestablishedthroughconsiderationofmaterialtoughness,materialflowstrength,andtheindividualqualificationrequirementsofthetoughnessvaluepervaluessought.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note18212;OtherstandardmethodsforthedeterminationoffracturetoughnessusingtheparametersK,J,andCTODarecontainedinTestMetho......
【中国标准分类号】:H22
【国际标准分类号】:77_040_10
【页数】:49P.;A4
【正文语种】:英语