Composite Structure Engineering

September14-16,2010Module:CompositeMaterialsTestMethodsCompositeStructureEngineeringSafetyAwarenessCourseDr.DanAdamsDirector,CompositeMechanicsLaboratoryUniversityofUtahSaltLakeCity,UT84112(801)[e-mail]tMethodsAGENDAConstituentandPrepregTestMethodsPhysicalTestMethodsforCompositesMechanicalTestMethodsforCompositesAdhesivesTestingTestMethodsforSandwichCompositesNon-DestructiveTestingConstituentTestMethodsFibers:CMH-17Vol.1,Chapter3Physicaltesting–Density,ThermalPropertiesMechanicaltesting–TensionMatrix:CMH-17Vol.1,Chapter4Thermal/Physicaltesting–Density,ElectricalResistivity,CoefficientofThermalExpansionMechanicaltesting–Tension,Compression,ShearFiberCharacterizationTesting:ExamplesPhysicalTesting:Forconstituentcontent(CMH-17Vol.1,Sections3.3,3.4)FiberdiameterFiberdensity–ASTMD3800,liquiddisplacementMechanicalTesting(CMH-17Vol.1,Section3.5)TensilepropertiesSinglefibertestsASTMD3379TowtestsASTMD4018MatrixCharacterizationTesting:ExamplesThermalAnalysis(CMH-17Vol.1,Section4.5)GlassTransitionTemperature,TgThermalexpansionpropertiesPhysicalTesting(CMH-17Vol.1,Section4.5)Matrixdensity–ASTMD792orD1505MechanicalTesting(CMH-17Vol.1,Section4.6)Tensileproperties-ASTMD638Compression,shear,flexurePrepregTestMethodsCMH-17Vol.1,Chapter5FocusonpropertiesandcharacteristicsofuncuredprepregFiberandresincontentResinextraction,ASTMC613Resinflow,geltimeSurfacetack,drapeCompositeMaterialsTestMethodsAGENDAConstituentandPrepregTestMethodsPhysicalTestMethodsforCompositesMechanicalTestMethodsforCompositesAdhesivesTestingTestMethodsforSandwichCompositesNon-DestructiveTestingPhysicalTestMethodsforCompositesCMH-17Vol.1,Chapter6Density-ASTMD792Constituentcontent(fiber,matrix,voids)MatrixdigestionASTMD3171IgnitionlossASTMD2584ImageanalysisFlammabilityThermalcycling/microcrackingEMIshieldingeffectivenessTgDetermination:ThermosetCompositesCMH-17Vol.1,Section6.6.3GlassTransitionTemperature,Tg:Atemperature-inducedchangeinthematrixmaterialfromtheglassytotherubberystateduringheating…Achangeinmatrixstiffnessoftwoorthreeordersofmagnitudeoccursduringtheglasstransition”DynamicMechanicalAnalysis(DMA)MostcommonmethodForcedoscillationmeasurementThermoMechanicalAnalysis(TMA)MeasurechangesinthermalexpansionDifferentialScanningCalorimetry(DSC)MeasurechangeinheatcapacityassociatedwithTgWellsuitedforneatresinspecimens,moredifficultwithcompositesCompositeMaterialsTestMethodsAGENDAConstituentandPrepregTestMethodsPhysicalTestMethodsforCompositesMechanicalTestMethodsforComposites(CMH-17Vol.1,Chapter6)AdhesivesTestingTestMethodsforSandwichCompositesNon-DestructiveTestingUniqueAspectsofTestingCompositeMaterialsOrthotropy:differentstiffnessesandstrengthsindifferentdirections.MinimumthicknessflatplatesfortestingPropertiesnotalwaysthesameintensionandcompressionElasticMaterialProperties•IsotropicMaterials(metals,plastics,ceramics,etc.)E,ν,GButonlytwoareindependent:•CompositeLamina(layer,ply)E1,E2,E3ν12,ν13,ν23G12,G13,G23ν)1(2E+=GTransverseIsotropy:E2=E3G12=G13ν12=ν13321)ν1(2E23223+=GStrengthPropertiesofaCompositeMaterial(Lamina)•3AxialTensileStrengthsS1+,S2+,S3+•3AxialCompressiveStrengthsS1-,S2-,S3-•3ShearStrengthsS12,S13,S23321TransverseIsotropy:S2=S3S12=S13TensionTestForFlatSpecimensASTMD3039Straight-sidedspecimens0.5in.wide,~8in.longAdhesivelybondedtabsStraingages(orextensometer)tomeasureaxialandtransversestrain(forE,ν12)RequiresvalidgagesectionfailureGageSectionTabTerminationRegionTabLengthTabRegionTabTaperAngleTabThicknessAdhesiveThicknessTabGeometricDesign•0.04-0.08in.thickness•Between5°and30°taperangleAdhesiveSelection•Highstrength•Thickbondline(0.010to0.050in.)Reference:DanielO.AdamsandDonaldF.Adams,“TabbingGuideforCompositeTestSpecimens,”DOT/FAA/AR-02/106,October2002.:DesignVariablesTabMaterial•G10orG11glass/epoxycircuitboardmaterialCategoriesofCompressionTestingShearloadingmethodsIITRIcompressiontest(ASTMD3410)EndloadingmethodsModifiedASTMD695CombinedloadingmethodsCombinedLoadingCompression(CLC),ASTMD6641CommonCompressionTestMethodsShearloadingASTMD3410•5.5in.longspecimen•0.5in.gagelength•Versatile•HeavyandexpensiveEndloadingModifiedASTMD695•3.18in.longspecimen•0.188in.gagelength•Separatetestsformodulus(untabbed)andstrength(tabbed)CombinedloadingASTMD6641•5.5in.longspecimen•0.5in.gagelength•AdjustableloadingratioviabolttorqueShearTesting–FlatCompositePlatesIn-planesheartesting:Stiffness:G12Strength:S12Out-of-plane(interlaminar)sheartestingStiffness:G13,G23Strength:S13,S23321τ12321τ13321τ23CommonTestMethods:In-PlaneShearIosipescuShearASTMD5379•3x0.75in.specimen•EdgeloadedV-NotchedRailShearASTMD7078•3x2.2in.specimen•Faceloaded•RecommendedbyCMH-17±45TensionShearASTMD3518•Combinedstressstate(notpureshear)•EasytoperformCommonTestMethods:Out-Of-Plane(Interlaminar)ShearIosipescuShearASTMD5379•3x0.75in.specimen•Edgeloaded•ModulusandstrengthShortBeamShearASTMD2344•Shearstrengthonly•Combinedstressstate•Smallspecimen•Simp