Designation:C1869−18StandardTestMethodforOpen-HoleTensileStrengthofFiber-ReinforcedAdvancedCeramicComposites1ThisstandardisissuedunderthefixeddesignationC1869;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethoddeterminestheopen-hole(notched)tensilestrengthofcontinuousfiber-reinforcedceramicmatrixcomposite(CMC)testspecimenswithasinglethrough-holeofdefineddiameter(either6mmor3mm).Theopen-holetensile(OHT)testmethoddeterminestheeffectofthesinglethrough-holeonthetensilestrengthandstressresponseofcontinuousfiber-reinforcedCMCsatambienttemperature.TheOHTstrengthcanbecomparedtothetensilestrengthofanun-notchedtestspecimentodeterminetheeffectofthedefinedopenholeonthetensilestrengthandthenotchsensitivityoftheCMCmaterial.Ifamaterialisnotchsensitive,thentheOHTstrengthofamaterialvarieswiththesizeofthethrough-hole.Commonly,largerholesintroducelargerstressconcentrationsandreducetheOHTstrength.1.2ThistestmethoddefinestwobaselineOHTtestspeci-mengeometriesandatestprocedure,basedonTestMethodsC1275andD5766/D5766M.Aflat,straight-sidedceramiccompositetestspecimenwithadefinedlaminatefiberarchi-tecturecontainsasinglethrough-hole(either6mmor3mmindiameter),centeredbylengthandwidthinthedefinedgagesection(Fig.1).Auniaxial,monotonictensiletestisperformedalongthedefinedtestreinforcementaxisatambienttemperature,measuringtheappliedforceversustime/displacementinaccordancewithTestMethodC1275.Mea-surementofthegagelengthextension/strainisoptional,usingextensometer/displacementtransducers.Bondedstraingagesareoptionalformeasuringlocalizedstrainsandassessingbendingstrainsinthegagesection.1.3Theopen-holetensilestrength(SOHTx)forthedefinedholediameterx(mm)isthecalculatedultimatetensilestrengthbasedonthemaximumappliedforceandthegrosscross-sectionalarea,disregardingthepresenceoft...
