ASTM-D2344

Designation:D2344/D2344M–00e1StandardTestMethodforShort-BeamStrengthofPolymerMatrixCompositeMaterialsandTheirLaminates1ThisstandardisissuedunderthefixeddesignationD2344/D2344M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.e1NOTE—ThetitlehasbeeneditoriallycorrectedinNovember2000.1.Scope1.1Thistestmethoddeterminestheshort-beamstrengthofhigh-modulusfiber-reinforcedcompositematerials.Thespeci-menisashortbeammachinedfromacurvedoraflatlaminateupto6.00mm[0.25in.]thick.Thebeamisloadedinthree-pointbending.1.2Applicationofthistestmethodislimitedtocontinuous-ordiscontinuous-fiber-reinforcedpolymermatrixcomposites,forwhichtheelasticpropertiesarebalancedandsymmetricwithrespecttothelongitudinalaxisofthebeam.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.1.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemmustbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnonconformancewiththestandard.2.ReferencedDocuments2.1ASTMStandards:D792TestMethodsforDensityandSpecificGravity(Rela-tiveDensity)ofPlasticsbyDisplacement2D883TerminologyRelatingtoPlastics2D2584TestMethodforIgnitionLossofCuredReinforcedResins3D2734TestMethodforVoidContentofReinforcedPlas-tics3D3171TestMethodforFiberContentofResin-MatrixCompositesbyMatrixDigestion4D3878TerminologyforHigh-ModulusReinforcingFibersandTheirComposites4D5229/D5229MTestMethodforMoistureAbsorptionPropertiesandEquilibriumConditioningofPolymerMa-trixCompositeMaterials4D5687/D5687MGuideforPreparationofFlatCompositePanelswithProcessingGuidelinesforSpecimenPrepara-tion4E4PracticesforForceVerificationofTestingMachines5E6TerminologyRelatingtoMethodsofMechanicalTest-ing5E18TestMethodsforRockwellHardnessandRockwellSuperficialHardnessofMetallicMaterials5E122PracticeforChoiceofSampleSizetoEstimateaMeasureofQualityforaLotorProcess6E177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethods6E456TerminologyRelatingtoQualityandStatistics6E1309GuideforIdentificationofCompositeMaterialsinComputerizedMaterialPropertyDatabases4E1434GuideforDevelopmentofStandardDataRecordsforComputerizationofMechanicalTestDataforHigh-ModulusFiber-ReinforcedCompositeMaterials4E1471GuideforIdentificationofFibers,Fillers,andCoreMaterialsinComputerizedMaterialPropertyDatabases43.Terminology3.1Definitions—TerminologyD3878definesthetermsre-latingtohigh-modulusfibersandtheircomposites.Terminol-ogyD883definestermsrelatingtoplastics.TerminologyE6definestermsrelatingtomechanicaltesting.TerminologyE456andPracticeE177definetermsrelatingtostatistics.Intheeventofaconflictbetweendefinitions,TerminologyD3878shallhaveprecedenceovertheotherdocuments.NOTE1—Ifthetermrepresentsaphysicalquantity,itsanalyticaldimensionsarestatedimmediatelyfollowingtheterm(orlettersymbol)infundamentaldimensionform,usingthefollowingASTMstandardsym-bologyforfundamentaldimensions,shownwithinsquarebrackets:[M]formass,[L]forlength,[T]fortime,[Q]forthermodynamictemperature,and[nd]fornondimensionalquantities.Useofthesesymbolsisrestrictedtoanalyticaldimensionswhenusedwithsquarebrackets,asthesymbolsmayhaveotherdefinitionswhenusedwithoutthebrackets.1ThistestmethodisunderthejurisdictionofASTMCommitteeD-30onCompositeMaterialsandisthedirectresponsibilityofSubcommitteeD30.04onLaminaandLaminateTestMethods.CurrenteditionapprovedMarch10,2000.PublishedJune2000.OriginallypublishedasD2344–65T.LastpreviouseditionD2344–84(1995).2AnnualBookofASTMStandards,Vol08.01.3AnnualBookofASTMStandards,Vol08.02.4AnnualBookofASTMStandards,Vol15.03.5AnnualBookofASTMStandards,Vol03.01.6AnnualBookofASTMStandards,Vol14.02.1Copyright©ASTM,100BarrHarborDrive,WestConshohocken,PA19428-2959,UnitedStates.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1balancedlaminate,n—acontinuousfiber-reinforcedlaminateinwhicheach+ulamina,measuredwithrespecttothelaminatereferenceaxis,isbalancedbya–ulaminaofthesamematerial(forexample,[0/+45/–45/+45/–45/0]).3.2.2short-beamstrength,n—theshearstressascalculatedinEq1,developedatthespecimenmid-planeatthefailureeventspecifiedin11.6.3.2.2.1Discussion—Althoughshearisthedominantappliedloadinginthistestmethod,theinternalstressesarecomplexandavarietyoffailuremodescanoccur.ElasticitysolutionsbyBergetal(1)7,Whitney(2),andSullivanandVanOene(3)havealldemonstratedinadequaciesinclassicalbeamtheoryindefiningthestressstateintheshort-beamconfiguration.Thesesolutionsshowthattheparabolicshear-stressdistributionaspredictedbyEq1onlyoccurs,andthennotexactly,onplanesmidwaybetweentheloadingnoseandsupportpoints.Awayfromtheseplanes,thestressdistributionsbecomeskewed,withpeakstressesoccurringneartheloadingno