中文摘要：

超声导波信号的波形具有多模态、波包混叠严重的问题,因此寻找有效的信号分析和模态识别方法成为超声导波焊缝检测技术中的重要研究内容。利用时-频分析方法中的Wigner-Ville分布及其改进方法对实验获得的焊缝特征导波回波信号进行处理,分析各波包对应的导波模态,有效识别缺陷回波信号,提取焊缝的结构和缺陷信息,实现模态分离和缺陷识别。分析结果与焊缝的实际结构和尺寸参数相吻合,该分析方法可为焊缝特征导波信号的分析处理提供现实依据。

英文摘要：

As the waveform of the ultrasonic guided wave has problem of existing multi-modes and aliased packets, finding an effective method for signal analysis and mode identification becomes important for ultrasonic guided wave weld testing. Based on the Wigner-Ville distribution of time -frequency analysis method and its improvement, the echo signal of weld feature -guided wave from experiment was processed, guided wave mode corresponding to each packet was analyzed, echo signal of defect was effectively recognized and the structure and defect information of weld were extracted to realize mode separation and defect recognition. The results are identical to the actual structure and size parameters of weld, showing that the analysis method provides basis for the signal processing of weld feature-guided waves.