Designation:C769−15AnAmericanNationalStandardStandardTestMethodforSonicVelocityinManufacturedCarbonandGraphiteMaterialsforUseinObtaininganApproximateValueofYoung’sModulus1ThisstandardisissuedunderthefixeddesignationC769;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1ThistestmethodcoversaprocedureformeasuringthesonicvelocityinmanufacturedcarbonandgraphitewhichcanbeusedtoobtainanapproximatevalueofYoung’smodulus.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C559TestMethodforBulkDensitybyPhysicalMeasure-mentsofManufacturedCarbonandGraphiteArticlesC747TestMethodforModuliofElasticityandFundamentalFrequenciesofCarbonandGraphiteMaterialsbySonicResonanceIEEE/ASTMSI10StandardforUseoftheInternationalSystemofUnits(SI)(theModernMetricSystem)3.Terminology3.1Definitions:3.1.1elasticmodulus,n—theratioofstresstostrain,inthestressrangewhereHooke’slawisvalid.3.1.2Young’smodulusormodulusofelasticity(E),n—theelasticmodulusintensionorcompression.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1endcorrectiontime(Te)—thenon-zerotimeofflight(correctionfactor),measuredinseconds,thatmayarisebyextrapolationofthepulsetraveltime,correctedforzerotime,backtozerosamplelength.3.2.2longitudinalsonicpulse—asonicpulseinwhichthedisplacementsareinthedirectionofpropagationofthepulse.3.2.3pulsetraveltime,(Tt)—thetotaltime,measuredinseconds,requiredforthesonicpulsetotraversethespecimenbeingtested,andfortheassociatedelectronicsignalstotraversethe...
