【英文标准名称】:StandardTestMethodforPhotoelasticMeasurementsofBirefringenceandResidualStrainsinTransparentorTranslucentPlasticMaterials
【原文标准名称】:透明或半透明塑性材料中双折射及残余应变的光弹性量度的标准试验方法
【标准号】:ASTMD4093-1995(2005)e1
【标准状态】:现行
【国别】:
【发布日期】:1995
【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】:D20.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:双折射;试验;塑料;测量;应变
【英文主题词】:birefringence;photoelasticmeasurements;photoelasticretardation;strain;strainopticalconstant;transparentplastics
【摘要】:Theobservationandmeasurementofstrainsintransparentortranslucentmaterialsisextensivelyusedinvariousmodelingtechniquesofexperimentalstressanalysis.Internalstrainsinducedinmanufacturingprocessessuchascasting,molding,welding,extrusion,andpolymerstretchingcanbeassessedandpartexhibitingexcessivestrainsidentified.Suchmeasurementscanleadtoeliminationofdefectiveparts,processimprovement,controlofannealingoperation,etc.Whentestingforphysicalproperties,polariscopicexaminationofspecimensisrequired,toeliminatethosespecimensexhibitingabnormalinternalstrainlevel(ordefects).Forexample:TestMethodsD638(Note8)andD882(Note11)recommendapolariscopicexamination.Thebirefringenceoforientedpolymerscanberelatedtoorientation,shrinkage,etc.Themeasurementsofbirefringenceaidincharacterizationofthesepolymers.Formanymaterials,theremaybeaspecificationthatrequirestheuseofthistestmethod,butwithsomeproceduralmodificationsthattakeprecedencewhenadheringtothespecification.Therefore,itisadvisabletorefertothatmaterialspecificationbeforeusingthistestmethod.Table1ofClassificationSystemD4000liststheASTMmaterialsstandardsthatcurrentlyexist.1.1Thistestmethodcoversmeasurementsofdirectionofprincipalstrains,1and2,andthephotoelasticretardation,,usingacompensator,forthepurposeofanalyzingstrainsintransparentortranslucentplasticmaterials.Thistestmethodcanbeusedtomeasurebirefringenceandtodeterminethedifferenceofprincipalstrainsornormalstrainswhentheprincipaldirectionsdonotchangesubstantiallywithinthelightpath.1.2Inadditiontothemethodusingacompensatordescribedinthistestmethod,othermethodsareinuse,suchasthegoniometricmethod(usingrotationoftheanalyzer)mostlyappliedformeasuringsmallretardation,andexpressingitasafractionofawavelength.Nonvisualmethodsemployingspectrophotometricmeasurementsandeliminatingthehumanjudgmentfactorarealsopossible.1.3Testdataobtainedbythistestmethodisrelevantandappropriateforuseinengineeringdesign.1.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnonconformancewiththestandard.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note1ThereisnoknownISOequivalenttothistestmethod.
【中国标准分类号】:G31
【国际标准分类号】:83_080_01
【页数】:11P.;A4
【正文语种】:


MIL-D-17847E, MILITARY SPECIFICATION: DEHYDRATOR, DESICCANT, SEMI-AUTOMATIC, HIGH PRESSURE AIR (29 SEP 1987)., This specification covers adsorptive purification and dehydration equipment for removing solid contaminants and particulate and vaporous water and oil from shipboard high pressure air systems.