Designation:D6068−10(Reapproved2018)StandardTestMethodforDeterminingJ-RCurvesofPlasticMaterials1ThisstandardisissuedunderthefixeddesignationD6068;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThistestmethodcoversthedeterminationoftheJ-integralversuscrackgrowthresistance(J-R)curvesforpolymericmaterials.1.2Thistestmethodisintendedtocharacterizetheslow,stablecrackgrowthresistanceofbend-typespecimensinsuchamannerthatitisgeometryinsensitivewithinlimitssetforthinthistestmethod.1.3Therecommendedspecimensarethethree-pointbend(SE(B))andpin-loadedcompacttension(C(T))specimens.Bothspecimenshavein-planedimensionsofconstantpropor-tionalityforallsizes.Specimenconfigurationsotherthanthoserecommendedinthistestmethodmayrequiredifferentproce-duresandvalidityrequirements.1.4Thistestmethoddescribesamultiplespecimenmethodthatrequiresopticalmeasurementofcrackextensionfromfracturesurfaces.Itisnotrecommendedforusewithmaterialsinwhichthecrackfrontcannotbedistinguishedfromaddi-tionaldeformationprocessesinadvanceofthecracktip.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.NOTE1—ThereisnoknownISOequivalenttothisstandard.1.7Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D618PracticeforConditioningPlasticsforTestingD4066ClassificationSystemforN...
