Designation:D3479/D3479M−19StandardTestMethodforTension-TensionFatigueofPolymerMatrixCompositeMaterials1ThisstandardisissuedunderthefixeddesignationD3479/D3479M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethoddeterminesthefatiguebehaviorofpolymermatrixcompositematerialssubjectedtotensilecyclicloading.Thecompositematerialformsarelimitedtocontinuous-fiberordiscontinuous-fiberreinforcedcompositesforwhichtheelasticpropertiesarespeciallyorthotropicwithrespecttothetestdirection.Thistestmethodislimitedtounnotchedtestspecimenssubjectedtoconstantamplitudeuniaxialin-planeloadingwheretheloadingisdefinedintermsofatestcontrolparameter.1.2Thistestmethodpresentstwoprocedureswhereeachdefinesadifferenttestcontrolparameter.1.2.1ProcedureA—Asysteminwhichthetestcontrolparameteristheload(stress)andthemachineiscontrolledsothatthetestspecimenissubjectedtorepetitiveconstantamplitudeloadcycles.Inthisprocedure,thetestcontrolparametermaybedescribedusingeitherengineeringstressorappliedloadasaconstantamplitudefatiguevariable.1.2.2ProcedureB—Asysteminwhichthetestcontrolparameteristhestrainintheloadingdirectionandthemachineiscontrolledsothatthetestspecimenissubjectedtorepetitiveconstantamplitudestraincycles.Inthisprocedure,thetestcontrolparametermaybedescribedusingengineeringstrainintheloadingdirectionasaconstantamplitudefatiguevariable.1.3ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemarenotnecessarilyexactequivalents;therefore,toensureconformancewiththestandard,eachsystemshallbeusedindependentlyoftheother,andvaluesfromthetwosystemsshallnotbecombined.1.3.1Withinthetexttheinch-poundunitsareshowninbrackets.1.4Thisstandarddoesnotpu...
