鋼絞線超聲導波檢測用磁致伸縮型傳感器的研制及應用研究.pdf

1、北京工業(yè)大學碩士學位論文鋼絞線超聲導波檢測用磁致伸縮型傳感器的研制及應用研究姓名：張易農申請學位級別：碩士專業(yè)：測試計量技術及儀器指導教師：何存富20080501Abstract毫曼m===；‘；m==。；；======；；====；；II!!!!!!!!!!!曼曼!鼉曼曼!曼苧!!!!曼曼!曼喜AbstractPrestressedsteelstrand，whichhasbeenwidelyusedinthehighways，brid

2、ges，foundationworkconstructionsbecauseofitslargecross—sectionalareaflexibilityetcTherefore，healthconditionmomtofingofsteelstrandisincreasinglygettingattentionRecentlymanynondestructiveinspectionmethodshavebeenappliedtopr

3、acticeengineering，suchasBarkhausennoisemethod，magneticleakagefluxmethod，fiberopticalsensingtechniqueandetcAsoneofthepotentialnondestructivemethods，ultrasonicguidedwavetechnologyissuitabletodetectdifferentwaveguidessuchas

4、bars，pipesandplatesandbecomesaresearchhotspotintheworldThispaperresearchestheexcitationandreceptionmethodsofthelongitudinalmodesinthesteelstrandbasedonmagnetostrictiveeffectareanalyzedtheoreticallyL(O，1)modeat160kHzischo

5、senfortheinspectionofseven—wiresteelstrandMagnetostrictivetransducerisdesignedandimplementedforexcitingandreceivingthisguidedwavemodeThechiefcontentsarelistedasfollowing：(1)Thedispersioncurvesinhelicalsteelstrandatthefre

6、quencyrangeof02MHzarecalculatednumericallyandanalyzedPropagationcharacteristicsofL(O，1)modeinthischosenfrequencyrangeisanalyzedAccordingtoabovetheoreticalanalysis，aspecialtypemagnetostrictivetransducerisdeveloped(2)Bycom

7、parisonwithotherdifferentlengthsandwindingdirections，threesectionspiraltubewithreversenormalwindingdirectionsissuitableassensingelementofoptimizedmagnetostrictivetransducer(3)Properimpedancematchingofmagnetostrictivetran

8、sducerisconfirmedthroughcomparisonofdifferentwaysofimpedancematchingbytesting(4)Accordingtocorrespondingtheoryofdesigningmagneticcircuit，doubleandthreemagneticcircuitsaredevelopedtoprovidebiasmagneticforsevenwiresteelstr

9、andMagneticinductionintensitybetweensteelstrand’SsurfaceandradialsectionsiscomparedandanalyzedusingdifferenttypesofmagneticcircuitsThechangeofmagneticdensityofdifferentstrandunderthecombinationofACandDCmagneticfieldindif

10、ferentpartsofsolenoidisanalyzed(5)Infreesteelstrandwithoutdefects，excitationandreceptionofultrasonicguidedwavesareachievedusingdevelopedmagnetostrictivetransducersArtificialnotchesincenterandhelicalwiresofsteelstrandared