【英文标准名称】:StandardTestMethodforDynamicYoung'sModulus,ShearModulus,andPoisson'sRatiobySonicResonance
【原文标准名称】:利用回声共振测试动态杨氏模量、剪切模数和泊松比的标准试验方法
【标准号】:ASTME1875-2000e1
【标准状态】:现行
【国别】:
【发布日期】:2000
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E28.04
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:测试方法;弹性(流体);陶瓷;工业瓷器;试验方法
【英文主题词】:dynamic;elasticmodulus;elasticproperties;Poisson'sratio;resonance;resonantbeam;shearmodulus;Young'smodulus
【摘要】:Thistestmethodhasadvantagesincertainrespectsovertheuseofstaticloadingsystemsformeasuringmoduli.5.1.1Thistestmethodisnondestructiveinnature.Onlyminutestressesareappliedtothespecimen,thusminimizingthepossibilityoffracture.5.1.2Theperiodoftimeduringwhichmeasurementstressisappliedandremovedisoftheorderofhundredsofmicroseconds.Withthistestmethoditisfeasibletoperformmeasurementsathightemperatures,wheredelayedelasticandcreepeffectswouldinvalidatemodulusmeasurementscalculatedfromstaticloading.Thistestmethodissuitablefordetectingwhetheramaterialmeetsspecifications,ifcognizanceisgiventooneimportantfactinmaterialsareoftensensitivetothermalhistory.Therefore,thethermalhistoryofatestspecimenmustbeconsideredincomparingexperimentalvaluesofmodulitoreferenceorstandardvalues.Specimendescriptionsshouldincludeanyspecificthermaltreatmentsthatthespecimenshavereceived.1.1Thistestmethodcoversthedeterminationofthedynamicelasticpropertiesofelasticmaterials.Specimensofthesematerialspossessspecificmechanicalresonantfrequenciesthataredeterminedbytheelasticmodulus,mass,andgeometryofthetestspecimen.Therefore,thedynamicelasticpropertiesofamaterialcanbecomputedifthegeometry,mass,andmechanicalresonantfrequenciesofasuitabletestspecimenofthatmaterialcanbemeasured.DynamicYoung'smodulusisdeterminedusingtheresonantfrequencyintheflexuralmodeofvibration.Thedynamicshearmodulus,ormodulusofrigidity,isfoundusingtorsionalresonantvibrations.DynamicYoung'smodulusanddynamicshearmodulusareusedtocomputePoisson'sratio.1.2Thistestmethodisspecificallyappropriateformaterialsthatareelastic,homogeneous,andisotropic(1).Materialsofacompositecharacter(particulate,whisker,orfiberreinforced)maybetestedbythistestmethodwiththeunderstandingthatthecharacter(volumefraction,size,morphology,distribution,orientation,elasticproperties,andinterfacialbonding)ofthereinforcementinthetestspecimenwillhaveadirecteffectontheelasticproperties.Thesereinforcementeffectsmustbeconsideredininterpretingthetestresultsforcomposites.Thistestmethodisnotsatisfactoryforspecimensthathavecracksorvoidsthataremajordiscontinuitiesinthespecimen.Neitheristhetestmethodsatisfactorywhenthesematerialscannotbefabricatedinauniformrectangularorcircularcrosssection.1.3Ahigh-temperaturefurnaceandcryogeniccabinetaredescribedformeasuringthedynamicelasticmoduliasafunctionoftemperaturefrom-195to1200oC.1.4Modificationofthistestmethodforuseinqualitycontrolispossible.Arangeofacceptableresonantfrequenciesisdeterminedforaspecimenwithaparticulargeometryandmass.Anyspecimenwithafrequencyresponsefallingoutsidethisfrequencyrangeisrejected.Theactualmodulusofeachspecimenneednotbedeterminedaslongasthelimitsoftheselectedfrequencyrangeareknowntoincludetheresonantfrequencythatthespecimenmustpossessifitsgeometryandmassarewithinspecifiedtolerances.1.5TherearematerialspecificASTMstandardsthatcoverthedeterminationofresonancefrequenciesandelasticpropertiesofspecificmaterialsbysonicresonanceorbyimpulseexcitationofvibration.TestMethodsC215,C623,C747,C848,C1198,andC1259maydifferfromthistestmethodinseveralareas(forexample;samplesize,dimensionaltolerances,samplepreparation).Thetestingofthesematerialsshallbedoneincompliancewiththesematerialspecificstandards.Wherepossible,theprocedures,samplespecifications,andcalculationsareconsistentwiththesetestmethods.1.6......
【中国标准分类号】:H23
【国际标准分类号】:81_060_20
【页数】:8P.;A4
【正文语种】:


【英文标准名称】:DTU25-231.Buildingworks.Suspendedceilingsmadefromterracottaelements.Technicalspecifications.
【原文标准名称】:DTU25-231.建筑工程.陶瓦元件制吊顶.技术规范
【标准号】:NFP68-202-1993
【标准状态】:现行
【国别】:法国
【发布日期】:1993-05-01
【实施或试行日期】:1993-05-05
【发布单位】:法国标准化协会(AFNOR)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:
【英文主题词】:
【摘要】:
【中国标准分类号】:P32
【国际标准分类号】:
【页数】:11P.;A4
【正文语种】:其他