Product Code:SAE MA3381
Title:Stud, Straight - 2.5 Dia Engagement, A286, MJ Metric, 8 X 1 - 8 X 1
Issuing Committee:E-25 General Standards For Aerospace And Propulsion Systems
Scope:No scope available.【英文标准名称】:StandardTestMethodsforPerformanceCharacteristicsofMetallicBondedResistanceStrainGages
【原文标准名称】:金属粘结电阻应变仪性能特征的标准试验方法
【标准号】:ASTME251-1992(2003)
【标准状态】:现行
【国别】:
【发布日期】:1992
【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】:E28.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:测量;机械试验;应变;试验;质量;延伸;伸长仪;试验设备;应变仪;工作特性
【英文主题词】:bondedresistancestraingages;elongation-metallicmaterials;gagefactor;performance;resistance;resistancegages;straingages;temperaturetests;transversesensitivity;performancecharacteristicsofmetallicbondedresistancestraingages,test
【摘要】:Straingagesarethemostwidelyuseddevicesforthedeterminationofmaterials,propertiesandforanalyzingstressesinstructures.However,performanceparametersofstraingagesareaffectedbyboththematerialsfromwhichtheyaremadeandtheirgeometricdesign.Thesetestmethodsdetailtheminimuminformationthatmustaccompanystraingagesiftheyaretobeusedwithacceptableaccuracyofmeasurement.Mostperformanceparametersofstraingagesrequiremechanicaltestingthatisdestructive.Sincetestgagescannotbeusedagain,itisnecessarytotreatdatastatisticallyandthenapplyvaluestotheremainingpopulationfromthesamelotorbatch.Failuretoacknowledgetheresultinguncertaintiescanhaveseriousrepercussions.Resistancemeasurementisnon-destructiveandcanbemadeforeachgage.Properlydesignedandmanufacturedstraingages,whosepropertieshavebeenaccuratelydeterminedandwithappropriateuncertaintiesapplied,representpowerfulmeasurementtools.Theycandeterminesmalldimensionalchangesinstructureswithexcellentaccuracy,farbeyondthatofotherknowndevices.Itisimportanttorecognize,however,thatindividualstraingagescannotbecalibrated.Ifcalibrationandtraceabilitytoastandardarerequired,straingagesshouldnotbeemployed.Tobeused,straingagesmustbebondedtoastructure.Goodresultsdependheavilyonthematerialsusedtocleanthebondingsurface,tobondthegage,andtoprovideaprotectivecoating.Skilloftheinstallerisanothermajorfactorinsuccess.Finally,instrumentationsystemsmustbecarefullydesignedtoassurethattheydonotundulydegradetheperformanceofthegages.Inmanycases,itisimpossibletoachievethisgoal.Ifso,allowancemustbemadewhenconsideringaccuracyofdata.Testconditionscan,insomeinstances,besoseverethaterrorsignalsfromstraingagesystemsfarexceedthosefromthestructuraldeformationstobemeasured.Greatcaremustbeexercisedindocumentingmagnitudesoferrorsignalssothatrealisticvaluescanbeplacedonassociateduncertainties.1.1Thepurposeofthisstandardistoprovideuniformtestmethodsforthedeterminationofstraingageperformancecharacteristics.Suggestedtestingequipmentdesignsareincluded.1.2TestMethodsE251describesmethodsandproceduresfordeterminingfivestraingageparameters:SectionPartI-GeneralRequirements7PartII-ResistanceataReferenceTemperature8PartIII-GageFactorataReferenceTemperature9PartIV-TemperatureCoefficientofGageFactor10PartV-TransverseSensitivity11PartVI-ThermalOutput12