Common Terms in Materials Testing - ADMET

Elongation at break or total elongation: The amount of plastic or ... Engineering strain: A dimensionless value that is the change in length ... SkiptocontentCommonTermsinMaterialsTestingPreviousNextThetermsbelowarecommonlyreferencedintheworldofmaterialstesting.ManyofthesedefinitionsaretakenfromASTME6StandardTerminologyRelatingtoMethodsofMechanicalTesting.Ductility:Theabilityofamaterialtodeformplasticallybeforefracture.Elasticlimit:Thegreateststressthatamaterialiscapableofsustainingwithoutanypermanentdeformationremaininguponcompletereleaseofstress.Elongationatbreakortotalelongation:Theamountofplasticorpermanentdeformationdeterminedafterfracturebyrealigningandfittingtogetherthebrokenendsofthespecimen.Elongationatfractureormaximumelongation:Theelongationatthetimeoffracture,includingbothplasticandelasticdeformationofthetensilespecimen.Usuallydeterminedbykeepinganextensometeronthespecimenthroughbreak.Engineeringstrain:Adimensionlessvaluethatisthechangeinlengthperunitlengthoftheoriginallineardimensionalongtheloadingaxisofthespecimen.Thisisfrequentlyexpressedininchesperinchorpercent.Engineeringstress:Thenormalstress,expressedinunitsofappliedforceperunitoforiginalcross-sectionalarea.Gagelength:Theoriginallengthofthatportionofthespecimenoverwhichstrainorchangeinlengthisdetermined.Hardness:Theresistanceofamaterialtodeformation,particularlypermanentdeformation,indentationorscratching.Hooke’sLaw(Hookeanbehavior):Withincertainforcelimits,thestressinamaterialisproportionaltothestrainthatproducedit.Mechanicalproperties:Thosepropertiesofamaterialthatareassociatedwiththeelasticandplasticreactionwhenforceisapplied.Offsetyieldstrength:Theengineeringstressatwhich,byconvention,itisconsideredthatplasticelongationofthespecimenhascommenced.Offsetyieldstrengthisdeterminedbyconstructingalineparalleltothelinearelasticregionofthestress-straincurveandshiftingitinthestraindirectionanamountspecifiedasapercentageofgagelength.Plasticstrainratio:Theratioofthetruestraininthewidthdirectiontothetruestraininthethicknessdirectionofasheetmaterialloadedbeyondyield.Proportionallimit:Thegreateststressthatamaterialiscapableofsustainingwithoutdeviationfromalinearrelationshipofstresstostrain.Reductionofarea:Thedifferencebetweentheoriginalcross-sectionalareaofatension-testspecimenandtheareaofitssmallestcross-sectionafterfracture.Thereductionofareaisexpressedasapercentageoftheoriginalcross-sectionalarea.Strainhardeningexponent,n:Ameasureoftheincreaseinhardnessandstrengthcausedbyplasticdeformationofatensilespecimen.Apowercurveisusedtoapproximatetheshapeofthestress-straincurvebetweenyieldandultimatestress.“n”isthecalculatedexponentofthepowercurve.Ultimatetensilestrengthortensilestrength:Themaximumtensilestressthatamaterialiscapableofsustaining.Tensilestrengthisthemaximumloadduringatensiontestcarriedtorupturedividedbytheoriginalcrosssectionalareaofthespecimen.Yieldbyextensionunderload(EUL):Theengineeringnstressatwhich,byconvention,itisconsideredthatplasticelongationofthespecimenhascommenced.EULisdeterminedbyconstructingalineperpendiculartothestrainaxisofastress-straincurveatastrainvaluethatisspecifiedasapercentageofgagelength.Yieldstrength:Theengineeringstressatwhich,byconvention,itisconsideredthatplasticelongationofthematerialhascommenced.Young’sModulusofElasticity:Theratioofstresstocorrespondingstrainbelowtheproportionallimit. Contactustoday!Haveaquestionaboutmaterialstesting?We'rereadytohelp!Contactustoday!ByNicholasSchaulsohn|November16th,2010|TestingIssues|ShareThisStory,ChooseYourPlatform!FacebookTwitterLinkedInPinterestRelatedPostsFiber-ReinforcedConcreteTesting:DesignChangesinASTMC1609EquipmentFiber-ReinforcedConcreteTesting:DesignChangesinASTMC1609EquipmentMarch18th,2022Deflection&HowToUseADeflectometerDeflection&HowToUseADeflectometerMarch1st,2022Ropes–ApplicationsandMechanicalTestingRopes–ApplicationsandMechanicalTestingJanuary29th,2022FoodPackagingandLabelTesting:AdhesiveShearStrengthFoodPackagingandLabelTesting:AdhesiveShearStrengthDecember29th,2021TensileTestingFAQsTensileTestingFAQsOctober20th,2021SpecimenAlignmentinMaterialTestingSpecimenAlignmentinMaterialTestingSeptember29th,2021ContactourEngineersToday!RecentPostsTestingSolutionsforMedicalDeviceConsultantsFiber-ReinforcedConcreteTesting:DesignChangesinASTMC1609EquipmentDeflection&HowToUseADeflectometerRopes–ApplicationsandMechanicalTestingFoodPackagingandLabelTesting:AdhesiveShearStrengthCategoriesBiaxialtorsiontestCoefficientoffrictionMedicalAdhesiveTestingNewsProductsTensileStrengthPropertiesTestHowTo'sTestingIssuesTorqueTestingVideoTagsAdhesivesadmetAerospaceAutomotiveAxial-TorsionAxial-TorsionTestingMachinesBendBiomaterialsBiomedicalBioTenseBioreactorCompressionConcreteconstructionConstructionMaterialseducationEducationandResearchElectronicsenvironmentalchamberseP2eXpert2600eXpert5600eXpert7600ExPressextensometersFatiguefatiguetestingFoamgripsandfixturesmedicaldevicesMedicalDeviceTestingMetalsMTESTQuattroMTESTQuattrosoftwarePeelplasticsPlasticsandElastomersPolymersretrofittensiletesttensiletestingTensionTextilesTorsionTorsionTestingMachinesuniversaltestingmachineContactInfo51MorganDriveNorwood,MA02062Phone:800-667-3220Email:[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