混凝土退化的非線性超聲特征識別研究.pdf

1、分類號UDC學(xué)校代碼10497學(xué)口萬劣膊忙聲大穿學(xué)位論文目混凝土退化的非線性超聲特征識別研究ResearehonConcreteDeteriorationDeteetionBasedonNonlinearUltrasonicFeatures文目題英題研究生姓名劉曙光姓名陳小佳職稱副教授學(xué)位博士指導(dǎo)教師單位名稱武漢理工大學(xué)郵編430063申請學(xué)位級別碩士學(xué)科專業(yè)名稱道路與鐵道工程論文提交日期20n年4月論文答辯日期Zon年5月學(xué)位授予單位

2、武漢理工大學(xué)學(xué)位授予日期答辯委員“主席二種皇二人.臀糕2011年05月武漢理工大學(xué)碩士學(xué)位論文AbstractBeeauseofthenonlinearityofconcretematerial，thetraditionalultrasoniemethodwhich15basedonthelinearwavetheory，eannotdeteetthecharaeteristiesofmaterials’intemalstructufe

3、and15notsensitivetomiero一cracksdeteetion，itslimitationonidentifieationandquantifieationofthematerialdegradationexists.StudiesshowthatthenoulinearultrasoniefeatUresaremoreobviousaftertheeoneretedamaged.Thereb又it15wihytoid

4、entifyquantifythedegadationdamageofconeretematerialsbyitsnonlinearultrasoniefeatures.Meanwhile，theultrasoniesignal15nonlinearandnonstationary，thetraditionalsignalProeessingmethodsmostbasedonthePremiseoflinearandstationar

5、轉(zhuǎn)50thetraditionalmethodshavesomelimitations.Therefe，usingnonlinearandnonstationaymethod15verybenefieialtononlinearultrasoniefeaturesofmaterials.Basedonnonlinearultrasonietheo以thisPaperusesHilbert一HuangTransfmtoProeessult

6、rasoniesignalextraetthenonlinearaeoustiefeatures50astoquantifythedegradationoftheeoneretematerials.Thenthedeteriorationoftheeoncrctematerials15estimated.Themaineontentandtheeonelusionsareasfollows:Thecharacteristicofeurr

7、entultrasoniesignalProeessingmethods15Presentedanditsboundednessonnoulinearandnonstationaysignals15analyZed.ThePrineiPle，imPlementationstePsandthecharaeteristiesofHilbert一HuangTransfmtoProeesssignal15discussed.Basedonthe

8、PrinciPleofHilbert一Huang，thesignalProeessingProgramandnumericalsimulationhasbeenworkout，theresultsshowthatIMFeomPonentsdiscomPosedbyEMDeanrefleetthefeaturesoftimesealesofsignalbetter.Inthemeantime，thenonlinearattenuation