ASTM-E466-07-Conducting-Force-Controlled-Constant-

Designation:E466–07StandardPracticeforConductingForceControlledConstantAmplitudeAxialFatigueTestsofMetallicMaterials1ThisstandardisissuedunderthefixeddesignationE466;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoverstheprocedurefortheperformanceofaxialforcecontrolledfatigueteststoobtainthefatiguestrengthofmetallicmaterialsinthefatigueregimewherethestrainsarepredominatelyelastic,bothuponinitialloadingandthroughoutthetest.Thispracticeislimitedtothefatiguetestingofaxialunnotchedandnotchedspecimenssubjectedtoaconstantamplitude,periodicforcingfunctioninairatroomtemperature.Thispracticeisnotintendedforapplicationinaxialfatiguetestsofcomponentsorparts.NOTE1—Thefollowingdocuments,althoughnotdirectlyreferencedinthetext,areconsideredimportantenoughtobelistedinthispractice:E739PracticeforStatisticalAnalysisofLinearorLinearizedStress-Life(S-N)andStrain-Life(´-N)FatigueDataSTP566HandbookofFatigueTesting2STP588ManualonStatisticalPlanningandAnalysisforFatigueExperiments3STP731TablesforEstimatingMedianFatigueLimits42.ReferencedDocuments2.1ASTMStandards:5E3GuideforPreparationofMetallographicSpecimensE467PracticeforVerificationofConstantAmplitudeDy-namicForcesinanAxialFatigueTestingSystemE468PracticeforPresentationofConstantAmplitudeFa-tigueTestResultsforMetallicMaterialsE606PracticeforStrain-ControlledFatigueTestingE739PracticeforStatisticalAnalysisofLinearorLinear-izedStress-Life(S-N)andStrain-Life(e-N)FatigueDataE1012PracticeforVerificationofTestFrameandSpecimenAlignmentUnderTensileandCompressiveAxialForceApplicationE1823TerminologyRelatingtoFatigueandFractureTest-ing3.Terminology3.1Definitions:3.1.1ThetermsusedinthispracticeshallbeasdefinedinTerminologyE1823.4.SignificanceandUse4.1Theaxialforcefatiguetestisusedtodeterminetheeffectofvariationsinmaterial,geometry,surfacecondition,stress,andsoforth,onthefatigueresistanceofmetallicmaterialssubjectedtodirectstressforrelativelylargenumbersofcycles.Theresultsmayalsobeusedasaguidefortheselectionofmetallicmaterialsforserviceunderconditionsofrepeateddirectstress.4.2Inordertoverifythatsuchbasicfatiguedatageneratedusingthispracticeiscomparable,reproducible,andcorrelatedamonglaboratories,itmaybeadvantageoustoconductaround-robin-typetestprogramfromastatistician’spointofview.Todosowouldrequirethecontrolorbalanceofwhatareoftendeemednuisancevariables;forexample,hardness,clean-liness,grainsize,composition,directionality,surfaceresidualstress,surfacefinish,andsoforth.Thus,whenembarkingonaprogramofthisnatureitisessentialtodefineandmaintainconsistencyapriori,asmanyvariablesasreasonablypossible,1ThispracticeisunderthejurisdictionofASTMCommitteeE08onFatigueandFractureandisthedirectresponsibilityofSubcommitteeE08.05onCyclicDeformationandFatigueCrackFormation.CurrenteditionapprovedNov.1,2007.PublishedNovember2007.Originallyapprovedin1972.Lastpreviouseditionapprovedin2002asE466–96(2002)´1.DOI:10.1520/E0466-07.2HandbookofFatigueTesting,ASTMSTP566,ASTM,1974.3Little,R.E.,ManualonStatisticalPlanningandAnalysis,ASTMSTP588,ASTM,1975.4Little,R.E.,TablesforEstimatingMedianFatigueLimits,ASTMSTP731,ASTM,1981.5ForreferencedASTMstandards,visittheASTMwebsite,@astm.org.ForAnnualBookofASTMStandardsvolumeinformation,refertothestandard’sDocumentSummarypageontheASTMwebsite.1Copyright.(C)ASTMInternational,100BarrHarborDrive,POboxC-700,WestConshohocken,Pennsylvania19428-2959,UnitedStatesCopyrightbyASTMInt'l(allrightsreserved);ThuSep1521:08:44EDT2011Downloaded/printedbyShanghaiJiaotongUniversitypursuanttoLicenseAgreement.Nofurtherreproductionsauthorized.withasmucheconomyasprudent.Allmaterialvariables,testinginformation,andproceduresusedshouldbereportedsothatcorrelationandreproducibilityofresultsmaybeattemptedinafashionthatisconsideredreasonablygoodcurrenttestpractice.4.3Theresultsoftheaxialforcefatiguetestaresuitableforapplicationtodesignonlywhenthespecimentestconditionsrealisticallysimulateserviceconditionsorsomemethodologyofaccountingforserviceconditionsisavailableandclearlydefined.5.SpecimenDesign5.1Thetypeofspecimenusedwilldependontheobjectiveofthetestprogram,thetypeofequipment,theequipmentcapacity,andtheforminwhichthematerialisavailable.However,thedesignshouldmeetcertaingeneralcriteriaoutlinedbelow:5.1.1Thedesignofthespecimenshouldbesuchthatfailureoccursinthetestsection(reducedareaasshowninFig.1andFig.2).Theacceptableratiooftheareas(testsectiontogripsection)toensureatestsectionfailureisdependentonthespecimengrippingmethod.Threadedendspecimensmayprovedifficulttoalignandfailureofteninitiatesatthesestressconcentrationswhentestingintheliferegimeofinterestinthispractice.Acaveatisgivenregardingthegagesectionwithsharpedges(thatis,squareorrectangularcrosssection)sincetheseareinherentweaknessesbecausetheslipofthegrainsatsharpedgesisnotconfinedbyneighbo