管道聲發(fā)射檢測配套技術(shù)實驗研究
在實驗室條件下,建立了一套超聲―聲發(fā)射檢測實驗系統(tǒng)。在不同缺陷情況下,對超聲波傳播特性進行實驗研究。利用STFT和小波分析技術(shù)對檢測到的信號進行了分析,結(jié)果表明,可以利用超聲波技術(shù)來對管道聲發(fā)射檢測到的缺陷進行更精確的定位,并能獲得更多的缺陷信息,為工程應用奠定了基礎(chǔ)。
Study on Matching Technique of Acoustic Emission Testing on Pipeline
(Mechanical Science And Engineering College, Da Qing Petroleum Institute, Daqing, 163318)
Abstract:An experimental system is set up in a laboratory which is based on ultrasonic-acoustic emission inspection. Propagation characteristics of ultrasonic waves are studied under several defect conditions. The signals from the testing are analyzed with STFT and wavelet analysis methods. The result shows that the defects detected by AET can be located exactly with ultrasonic method, and that with UT we can get more defect information, which set up the basis for engineering application.
Keywords:Pipe,Acoustic emission,Ultrasonic,Wavelet analysis
【1】。而且利用聲發(fā)射技術(shù)對管道的泄漏進行檢測,前人已經(jīng)做過大量的工作,取得了突出的成果。但是聲發(fā)射技術(shù)也有它的局限性,它不能對缺陷部位進行精確的定位,一般指示的是缺陷的大致范圍,所以在工業(yè)應用中通常需要其它的常規(guī)方法來與之配合工作,以確定缺陷的準確位置[2]。
o至177o,頻率范圍50到1000kHz,靈敏度為69 dB。實驗中采用的前置放大器是2/4/6前置放大器。實驗利用超聲探傷儀模擬聲源,采用斜探頭傳輸。斜探頭的頻率為2.5KHz,晶片尺寸13x13mm,檢測范圍10~200mm,靈敏度70~78dB,近場長度7~60mm,K值1.5,前沿長度13度,折射角為45o,數(shù)字式超聲探傷儀CTS-36。實驗對象為長為5.31m ,外徑為φ102mm,壁厚為10mm的管道,材料為45鋼。
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