Designation:C1198−09(Reapproved2013)StandardTestMethodforDynamicYoung’sModulus,ShearModulus,andPoisson’sRatioforAdvancedCeramicsbySonicResonance1ThisstandardisissuedunderthefixeddesignationC1198;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofthedy-namicelasticpropertiesofadvancedceramics.Specimensofthesematerialspossessspecificmechanicalresonantfrequen-ciesthataredeterminedbytheelasticmodulus,mass,andgeometryofthetestspecimen.Therefore,thedynamicelasticpropertiesofamaterialcanbecomputedifthegeometry,mass,andmechanicalresonantfrequenciesofasuitabletestspeci-menofthatmaterialcanbemeasured.DynamicYoung’smodulusisdeterminedusingtheresonantfrequencyintheflexuralmodeofvibration.Thedynamicshearmodulus,ormodulusofrigidity,isfoundusingtorsionalresonantvibra-tions.DynamicYoung’smodulusanddynamicshearmodulusareusedtocomputePoisson’sratio.1.2Thistestmethodmeasurestheresonantfrequenciesoftestspecimensofsuitablegeometrybymechanicallyexcitingthematcontinuouslyvariablefrequencies.Mechanicalexcita-tionofthebarsisprovidedthroughtheuseofatransducerthattransformsacyclicelectricalsignalintoacyclicmechanicalforceonthespecimen.Asecondtransducersensestheresultingmechanicalvibrationsofthespecimenandtransformsthemintoanelectricalsignal.Theamplitudeandfrequencyofthesignalaremeasuredbyanoscilloscopeorothermeanstodetectresonantvibrationinthedesiredmode.Theresonantfrequencies,dimensions,andmassofthespecimenareusedtocalculatedynamicYoung’smodulusanddynamicshearmodu-lus.(SeeFig.1)1.3Thistestmethodisspecificallyappropriateforadvancedceramicsthatareelastic,homogeneous,andisotropic(1).2Advancedceramicsofacompositecharacter(particulate,whisker,orfiberreinforced)maybetestedbythistestmethodwiththeunderstandingthatthecharacter(volumefraction...
