Designation:D7615/D7615M−11StandardPracticeforOpen-HoleFatigueResponseofPolymerMatrixCompositeLaminates1ThisstandardisissuedunderthefixeddesignationD7615/D7615M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticeprovidesinstructionsformodifyingstaticopen-holetensileandcompressivestrengthtestmethodstodeterminethefatiguebehaviorofcompositematerialssub-jectedtocyclictensileorcompressiveforces,orboth.Thecompositematerialformsarelimitedtocontinuous-fiberrein-forcedpolymermatrixcompositesinwhichthelaminateisbothsymmetricandbalancedwithrespecttothetestdirection.Therangeofacceptabletestlaminatesandthicknessesaredescribedin8.2.1.2ThispracticesupplementsTestMethodsD5766/D5766MandD6484/D6484Mwithprovisionsfortestingspecimensundercyclicloading.Severalimportanttestspeci-menparameters(forexample,fatigueforce(stress)ratio)arenotmandatedbythispractice;however,repeatableresultsrequirethattheseparametersbespecifiedandreported.1.3Thispracticeislimitedtotestspecimenssubjectedtoconstantamplitudeuniaxialloading,wherethemachineiscontrolledsothatthetestspecimenissubjectedtorepetitiveconstantamplitudeforce(stress)cycles.Eitherengineeringstressorappliedforcemaybeusedasaconstantamplitudefatiguevariable.Therepetitiveloadingsmaybetensile,compressive,orreversed,dependinguponthetestspecimenandprocedureutilized.1.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.4.1Withinthetexttheinch-poundunitsareshowninbrackets.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishap...
