【英文标准名称】:StandardTestMethodforDynamicYoung''sModulus,ShearModulus,andPoisson''sRatioforAdvancedCeramicsbySonicResonance
【原文标准名称】:声谐振动测定动态扬氏模量、剪切模量和泊松比的标准试验方法
【标准号】:ASTMC1198-2009
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【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】:C28.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:advancedceramics;bar;beam;cylindricalrod;dynamic;elasticmodulus;flexure;elasticproperties;Poisson'sratio;resonance;resonantbeam;shearmodulus;torsion;Young'smodulus;Advancedceramics;Audiooscillator;Dynamicelasticproperties;Elas
【摘要】:Thistestmethodmaybeusedformaterialdevelopment,characterization,designdatageneration,andqualitycontrolpurposes.Itisspecificallyappropriatefordeterminingthemodulusofadvancedceramicsthatareelastic,homogeneous,andisotropic.Thistestmethodisnondestructiveinnature.Onlyminutestressesareappliedtothespecimen,thusminimizingthepossibilityoffracture.Theperiodoftimeduringwhichmeasurementstressisappliedandremovedisoftheorderofhundredsofmicroseconds.Withthistestmethoditisfeasibletoperformmeasurementsathightemperatures,wheredelayedelasticandcreepeffectswouldinvalidatemodulusmeasurementscalculatedfromstaticloading.Thistestmethodhasadvantagesincertainrespectsovertheuseofstaticloadingsystemsformeasuringmoduliinadvancedceramics.Itisnondestructiveinnatureandcanbeusedforspecimenspreparedforothertests.Specimensaresubjectedtominutestrains;hence,themoduliaremeasuredatorneartheoriginofthestress-straincurvewiththeminimumpossibilityoffracture.Theperiodoftimeduringwhichmeasurementstressisappliedandremovedisoftheorderofhundredsofmicroseconds.Withthistestmethoditisfeasibletoperformmeasurementsathightemperatures,wheredelayedelasticandcreepeffectswouldinvalidatemodulusmeasurementscalculatedfromstaticloading.Thesonicresonantfrequencytechniquecanalsobeusedasanondestructiveevaluationtoolfordetectingandscreeningdefects(cracks,voids,porosity,densityvariations)inceramicparts.Thesedefectsmaychangetheelasticresponseandtheobservedresonantfrequencyofthetestspecimen.GuideE2001describesaprocedurefordetectingsuchdefectsinmetallicandnonmetallicpartsusingtheresonantfrequencymethod.1.1Thistestmethodcoversthedeterminationofthedynamicelasticpropertiesofadvancedceramics.Specimensofthesematerialspossessspecificmechanicalresonantfrequenciesthataredeterminedbytheelasticmodulus,mass,andgeometryofthetestspecimen.Therefore,thedynamicelasticpropertiesofamaterialcanbecomputedifthegeometry,mass,andmechanicalresonantfrequenciesofasuitabletestspecimenofthatmaterialcanbemeasured.DynamicYoung''smodulusisdeterminedusingtheresonantfrequencyintheflexuralmodeofvibration.Thedynamicshearmodulus,ormodulusofrigidity,isfoundusingtorsionalresonantvibrations.DynamicYoung''smodulusanddynamicshearmodulusareusedtocomputePoisson''sratio.1.2Thistestmethodmeasurestheresonantfrequenciesoftestspecimensofsuitablegeometrybymechanicallyexcitingthematcontinuouslyvariablefrequencies.Mechanicalexcitationofthebarsisprovidedthroughtheuseofatransducerthattransformsacyclicelectricalsignalintoacyclicmechanicalforceonthespecimen.Asecondtransducersensestheresultingmechanicalvibrationsofthespecimenandtransformsthemintoanelectricalsignal.Theamplitudeandfrequencyofthesignalaremeasuredbyanoscilloscopeorothermeanstodetectresonantvibrationinthedesiredmode.Theresonantfrequencies,dimensions,andmassofthespecimenareusedtocalculatedynamicYoung''smodulusanddynamicshearmodulus.(SeeFig.1)1.3Thistestmethodisspecificallyappropriateforadvancedceramicsthatareelastic,homogeneous,andisotropic(3).Advancedceramicsofacompositecharacter(particulate,whisker,orfiberreinforced)maybetestedbythistestmethodwiththeunderstandingthatthecharacter(volumefraction,size,morphology,distribution,orientation,elasticproperties,andinterfacialbonding)ofthereinforcementinthetest......
【中国标准分类号】:Q30
【国际标准分类号】:
【页数】:11P.;A4
【正文语种】:英语


【英文标准名称】:Videorecording-12,65mmtypeD-11format-Part2:Picturecompressionanddatastream(IEC62356-2:2003);GermanversionEN62356-2:2004
【原文标准名称】:视频记录.12.65mm型D-11格式.第2部分:图像压缩和数据流
【标准号】:DINEN62356-2-2005
【标准状态】:现行
【国别】:德国
【发布日期】:2005-03
【实施或试行日期】:2005-03-01
【发布单位】:德国标准化学会(DIN)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:
【英文主题词】:
【摘要】:ThisInternationalStandardspecifiesthecompressionofahigh-definitionsourceformattoadual-channelpacketizeddatastreamformatwhichissuitableforrecordingondiscandtapestoragedevicesincludingthetypeD11taperecorder.
【中国标准分类号】:M71
【国际标准分类号】:33_160_40
【页数】:56P;A4
【正文语种】:德语