超声导波无损检测技术由于其传播距离远、检测范围大等优良性能,被广泛应用于航空航天、油气管道、压力容器等领域的检测.由于沿波导的长距离传播,超声导波除了有一般体波的特点外,还具有频散和多模态特性,该特性极大地限制了超声导波的检测效果,增大了特征识别的困难.开展针对超声导波频散和多模态特性的研究具有重要的理论和现实意义.本文通过分析超声导波频散和多模态特性的特点,提出从导波信号处理角度出发,采用形态分量分析的信号处理技术,深入研究导波信号的形态分解问题,并通过实验信号对方法的有效性进行了验证,为解决频散和多模态的影响以及为复杂导波信号的分析提供关键技术.%Ultrasonic guided waves were widely used in aeronautics, pipeline, vessels and so on, because of its long distance propagation and large range detection property. Due to the long distance propagation along waveguides, the guided waves were not only possess the feature of ultrasonic bulk waves,but also dispersion and multi-modes characters, which limited detection effect of guided waves and increased the difficulty of feature recognition. It has great theoretical and realistic sense to research the dispersion and multi-modes for ultrasonic guided waves. In this paper, the characters of dispersion and multi-modes were analyzed carefully, and a signal processing point of view was considered. The modeling and morphology decomposition of guided waves signals were proposed by the use of morphology component analysis techniques. The validations of these methods were realized through experiments. All of research results can provide key technologies for decreasing the effect of dispersion and multi-modes and analyzing complex for guided waves signals.
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