ASTM-E-647

Designation:E647–08´1StandardTestMethodforMeasurementofFatigueCrackGrowthRates1ThisstandardisissuedunderthefixeddesignationE647;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.´1NOTE—A5.7waseditoriallyrevisedinMay2010.1.Scope1.1Thistestmethod2coversthedeterminationoffatiguecrackgrowthratesfromnear-thresholdtoKmaxcontrolledinstability.Resultsareexpressedintermsofthecrack-tipstress-intensityfactorrange(DK),definedbythetheoryoflinearelasticity.1.2Severaldifferenttestproceduresareprovided,theopti-mumtestprocedurebeingprimarilydependentonthemagni-tudeofthefatiguecrackgrowthratetobemeasured.1.3Materialsthatcanbetestedbythistestmethodarenotlimitedbythicknessorbystrengthsolongasspecimensareofsufficientthicknesstoprecludebucklingandofsufficientplanarsizetoremainpredominantlyelasticduringtesting.1.4Arangeofspecimensizeswithproportionalplanardimensionsisprovided,butsizeisvariabletobeadjustedforyieldstrengthandappliedforce.Specimenthicknessmaybevariedindependentofplanarsize.1.5Thedetailsofthevariousspecimensandtestconfigu-rationsareshowninAnnexA1-AnnexA3.Specimenconfigu-rationsotherthanthosecontainedinthismethodmaybeusedprovidedthatwell-establishedstress-intensityfactorcalibra-tionsareavailableandthatspecimensareofsufficientplanarsizetoremainpredominantlyelasticduringtesting.1.6Residualstress/crackclosuremaysignificantlyinfluencethefatiguecrackgrowthratedata,particularlyatlowstress-intensityfactorsandlowstressratios,althoughsuchvariablesarenotincorporatedintothecomputationofDK.1.7ValuesstatedinSIunitsaretoberegardedasthestandard.Valuesgiveninparenthesesareforinformationonly.1.8Thistestmethodisdividedintotwomainparts.Thefirstpartgivesgeneralinformationconcerningtherecommenda-tionsandrequirementsforfatiguecrackgrowthratetesting.Thesecondpartiscomposedofannexesthatdescribethespecialrequirementsforvariousspecimenconfigurations,spe-cialrequirementsfortestinginaqueousenvironments,andproceduresfornon-visualcracksizedetermination.Inaddition,thereareappendicesthatcovertechniquesforcalculatingda/dN,determiningfatiguecrackopeningforce,andguidelinesformeasuringthegrowthofsmallfatiguecracks.Generalinformationandrequirementscommontoallspecimentypesarelistedasfollows:SectionReferencedDocuments2Terminology3SummaryofUse4SignificanceandUse5Apparatus6SpecimenConfiguration,Size,andPreparation7Procedure8CalculationsandInterpretationofResults9Report10PrecisionandBias11SpecialRequirementsforTestinginAqueousEnvironmentsAnnexA4GuidelinesforUseofCompliancetoDetermineCrackSizeAnnexA5GuidelinesforElectricPotentialDifferenceDeterminationofCrackSizeAnnexA6RecommendedDataReductionTechniquesAppendixX1RecommendedPracticeforDeterminationofFatigueCrackOpeningForceFromComplianceAppendixX2GuidelinesforMeasuringtheGrowthRatesOfSmallFatigueCracksAppendixX31.9Specialrequirementsforthevariousspecimenconfigu-rationsappearinthefollowingorder:TheCompactSpecimenAnnexA1TheMiddleTensionSpecimenAnnexA2TheEccentrically-LoadedSingleEdgeCrackTensionSpeci-menAnnexA31.10Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:3E4PracticesforForceVerificationofTestingMachines1ThistestmethodisunderthejurisdictionofASTMCommitteeE08onFatigueandFractureandisthedirectresponsibilityofSubcommitteeE08.06onCrackGrowthBehavior.CurrenteditionapprovedApril1,2008.PublishedMay2008.Originallyapprovedin1978.Lastpreviousapprovedin2005asE647–05.DOI:10.1520/E0647-08.2ForadditionalinformationonthistestmethodseeRR:E24–1001.AvailablefromASTMHeadquarters,100BarrHarborDrive,WestConshohocken,PA19428.3ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.1Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.CopyrightASTMInternationalProvidedbyIHSunderlicensewithASTMNotforResaleNoreproductionornetworkingpermittedwithoutlicensefromIHS--`,,```,,,,````-`-`,,`,,`,`,,`---//^:^^#^~^^~~::^#$~@@#:$@^^~^:#~~@^^$^@^^:#::$\\E6TerminologyRelatingtoMethodsofMechanicalTestingE8/E8MTestMethodsforTensionTestingofMetallicMaterialsE337TestMethodforMeasuringHumiditywithaPsy-chrometer(theMeasurementofWet-andDry-BulbTem-peratures)E338TestMethodofSharp-NotchTensionTestingofHigh-StrengthSheetMaterialsE399TestMethodforLinear-ElasticPlane-StrainFractureToughnessKIcofMetallicMaterialsE467PracticeforVerificationofConstantAmplitudeDy-namicForcesinanAxialFatigueTestingSystemE561TestMethodforK-RCurveDeterminationE1012PracticeforVerificationofTestFrameandSpecimenAlignmentUnderTensileandCompressiveAxialForceApplicationE1820Te