基于小波变换及Wigner-Ville变换方法的超声导波信号分析  

Ultrasonic Guided Wave Signal Analysis Based on Wavelet and Wigner-Ville Transform Processing

作　　者：何存富[1] 李颖[1] 王秀彦[1] 吴斌[1] 李隆涛[1] 

机构地区：[1]北京工业大学机电学院,北京100022

出　　处：《实验力学》2005年第4期584-588,共5页Journal of Experimental Mechanics

基　　金：国家自然科学基金(19972003;10272007);北京市自然科学基金(3011001);北京市自然科学基金(3992006);北京市优秀人才培养专项经费资助项

摘　　要：对结构中缺陷的检测和识别是无损检测中的一项重要研究课题,超声导波由于可在短时间内检测很远距离,故它的一个重要应用便是管材的检测。因而对导波检测信号的处理成为一重要研究内容,本文利用时-频分析方法中的小波变换和Wigner-Ville变换对管道和抽油杆缺陷的导波检测信号进行了分析处理。实验结果表明,进行小波变换后,缺陷回波信号的信噪比大大提高,直径仅1mm的小孔缺陷可容易地被识别出来,准确检测出其位置;通过对信号进行Wigner-Ville的相关变换,可同时在时频两域内对缺陷的回波信号进行分析,使缺陷辨别起来简单易行。两种信号处理方法的超声导波应用研究为以后导波信号的处理提供了新的实现依据。The detection and characterization of defects in structures is an important issue in non- destructive testing. One of the main applications of ultrasonic guided waves is for pipe inspection, since it can inspect long distances in a short time. But the processing of the received signal is still an open problem. In this paper, the methods of wavelet transform and Wigner-Ville transform are applied to the signal analysis of guided wave inspection of defects in a hollow sucker rod. The experimental results show that after wavelet transform is applied, a high signal/noise ratio of defect echo signals is presented, defects can be identified and located easily; and after Wigner-Ville transform is adopted, defect echo signals can be shown clearly in time-frequency domain and defects can be identified easily. The investigation about application of the two signal processing methods to guided wave inspection signals supplies new realization basis for the signal processing of guided wave inspection.

关 键 词：无损检测 导渡 抽油杆 小波 Wigner—Ville变换 

分 类 号：O348[理学—固体力学]