Designation:D6641/D6641M−16´2StandardTestMethodforCompressivePropertiesofPolymerMatrixCompositeMaterialsUsingaCombinedLoadingCompression(CLC)TestFixture1ThisstandardisissuedunderthefixeddesignationD6641/D6641M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—AlabelinFigure3wascorrectededitoriallyinMarch2017.ε2NOTE—EditorialcorrectionsweremadetotheadjunctinformationinMarch2021.1.Scope1.1Thistestmethoddeterminesthecompressivestrengthandstiffnesspropertiesofpolymermatrixcompositematerialsusingacombinedloadingcompression(CLC)(1)2testfixture.Thistestmethodisapplicabletogeneralcompositesthatarebalancedandsymmetric.Thespecimenmaybeuntabbed(ProcedureA)ortabbed(ProcedureB),asrequired.Onerequirementforasuccessfultestisthatthespecimenendsdonotcrushduringthetest.Untabbedspecimensareusuallysuitableforusewithmaterialsofloworthotropy,forexample,fabrics,choppedfibercomposites,andlaminateswithamaxi-mumof50%0°plies,orequivalent(see6.4).Materialsofhigherorthotropy,includingunidirectionalcomposites,typi-callyrequiretabs.1.2Thecompressiveforceisintroducedintothespecimenbycombinedend-andshear-loading.Incomparison,TestMethodD3410/D3410Misapureshear-loadingcompressiontestmethodandTestMethodD695isapureend-loadingtestmethod.1.3Unidirectional(0°plyorientation)compositesaswellasmulti-directionalcompositelaminates,fabriccomposites,choppedfibercomposites,andsimilarmaterialscanbetested.1.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Withinthetesttheinch-poundunitsareshowninbrackets.Thevaluesstatedineachsystemarenotexactequivalents;therefore,eachsystemmustbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnonconformancewiththestandard.NOTE1—Additionalproceduresfordeterminingthecompressiveprop-ertiesofpolymermatrixco...
