DIN EN 300197-2001 固定无线电系统.点对点设备.在38GHz下运行的数字信号传输用无线电系统的参数

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标准名称：	暗筒式日照计技术条件
中标分类：	仪器、仪表 >> 其他仪器仪表 >> 气象仪器
替代情况：	转化为JB/T 9459-1999
发布日期：
实施日期：	1991-07-01
首发日期：
作废日期：
出版日期：
页数：	3页

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【英文标准名称】:StandardPracticeforAcousticEmissionExaminationofPlate-likeandFlatPanelCompositeStructuresUsedinAerospaceApplications
【原文标准名称】:航空航天设备用板状和平板复合结构的声发射检验的标准实施规程
【标准号】:ASTME2661/E2661M-2010
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【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】:E07.04
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:acousticemission(AE);acousticemissionfromcomposites;AE;aerospacecomposites;continuousfibers;fiber/polymercomposites;flatpanels;highmodulusfibers;laminates;nondestructivetesting(NDT);structuralhealthmonitoring(SHM)
【摘要】:ThisAEexaminationisusefultodetectmicro-damagegeneration,accumulationandgrowthofneworexistingflaws.Theexaminationisalsousedtodetectsignificantexistingdamagefromfriction-basedAEgeneratedduringloadingorunloadingoftheseregions.Thedamagemechanismsthatcanbedetectedincludematrixcracking,fibersplitting,fiberbreakage,fiberpull-out,debondinganddelamination.Duringloading,unloadingandloadholding,damagethatdoesnotemitAEenergywillnotbedetected.WhenthedetectedsignalsfromAEsourcesaresufficientlyspacedintimesoasnottobeclassifiedascontinuousAE,thispracticeisusefultolocatetheregion(s)ofthe2-Dtestsamplewherethesesourcesoriginatedandtheaccumulationofthesesourceswithchangingloadand/ortime.TheprobabilityofdetectionofthepotentialAEsourcesdependsonthenatureofthedamagemechanisms,flawcharacteristicsandotheraspects.ForadditionalinformationseeX1.4.Concentrateddamageinfiber/polymercompositescanleadtoprematurefailureofthecompositeitem.Hence,theuseofAEtodetectandlocatesuchdamageisparticularlyimportant.AE-detectedflawsordamageconcentratedinacertainregionmaybefurthercharacterizedbyotherNDEtechniques(forexample,visual,ultrasonic,etc.)andmayberepairedasappropriate.Repairprocedurerecommendationsandthesubsequentexaminationoftherepairareoutsidethescopeofthispractice.ForadditionalinformationseeX1.5.Thispracticedoesnotaddresssandwichcore,foamcoreorhoneycombcoreplate-likecompositesduetothefactthatcurrentlythereislittleinthewayofpublishedworkonthesubjectresultinginalackofasufficientknowledgebase.RefertoGuideE2533foradditionalinformationabouttypesofdefectsdetectedbyAE,generaloverviewofAEasappliedtopolymermatrixcomposites,discussionoftheFelicityratio(FR)andKaisereffect,advantagesandlimitations,AEofcompositepartsotherthanflatpanels,andsafetyhazards.1.1Thispracticecoversacousticemission(AE)examinationormonitoringofpanelandplate-likecompositestructuresmadeentirelyoffiber/polymercomposites.1.2TheAEexaminationdetectsemissionsourcesandlocatestheregion(s)withinthecompositestructurewheretheemissionoriginated.WhenproperlydevelopedAE-basedcriteriaforthecompositeitemareinplace,theAEdatacanbeusedfornondestructiveexamination(NDE),characterizationofprooftesting,documentationofqualitycontrolorfordecisionsrelativetostructural-testterminationpriortocompletionofaplannedtest.OtherNDEmethodsmaybeusedtoprovideadditionalinformationaboutlocateddamageregions.ForadditionalinformationseeAppendixX1.1.3Thispracticecanbeappliedtoaerospacecompositepanelsandplate-likeelementsasapartofincominginspection,duringmanufacturing,afterassembly,continuously(duringstructuralhealthmonitoring)andatperiodicintervalsduringthelifeofastructure.1.4Thispracticeismeantforfiberorientationsthatincludecross-plies,angle-plylaminatesortwo-dimensionalwovenfabrics.Thispracticealsoappliesto3-Dreinforcement(forexample,stitched,z-pinned)whenthefibercontentinthethirddirectionislessthan5%(basedonthewholecomposite).1.5Thispracticeisdirectedtowardcompositematerialsthattypicallycontaincontinuoushighmodulusgreaterthan20GPa[3Msi]fibers.1.6ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combi......
【中国标准分类号】:V10
【国际标准分类号】:49_025_40
【页数】:18P.;A4
【正文语种】:英语