Abstract Structural health monitoring based on guided waves is a promising technology that can continuously monitor and identify structural damage. Due to the variable cross-sectional characteristics of the turnout straight switch rail along the longitudinal direction of the line, it is still a challenging task to understand and clarify the guided wave propagation characteristics of the structure. In this paper, a method for analyzing the guided wave propagation characteristics of the turnout straight switch rail with variable cross-section is proposed, and the effectiveness of the method verified by finite element simulation and field experiments. The results show that the dispersion characteristics of the turnout straight switch rail change slowly along the longitudinal direction, and that at a local level the dispersion characteristics are in fact similar to rails of constant cross-section. Based on this, a three-dimensional dispersion surface with cross-sectional position information is proposed, after which the variation regularity of dispersion characteristics along the longitudinal direction is analyzed in combination with the mode shapes of the cross section at different positions. This method can provide a theoretical basis for damage detection in turnout straight switch rail, as well as for the selection of guided wave frequency and mode recognition.

中文翻译：

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变截面道岔轨道导波传播特性研究

摘要 基于导波的结构健康监测是一种有前景的技术，可以连续监测和识别结构损伤。由于道岔直道岔轨道沿线路纵向的截面特性可变，理解和阐明结构的导波传播特性仍然是一项具有挑战性的任务。本文提出了一种分析变截面道岔直道岔导轨导波传播特性的方法，并通过有限元仿真和现场试验验证了该方法的有效性。结果表明，道岔直道岔轨的色散特性沿纵向缓慢变化，并且在局部水平上，分散特性实际上类似于恒定横截面的钢轨。在此基础上，提出了具有截面位置信息的三维色散面，然后结合截面不同位置的模态振型分析了色散特性沿纵向的变化规律。该方法可为道岔直道岔钢轨损伤检测、导波频率选择和模态识别提供理论依据。然后结合不同位置截面的模态振型分析色散特性沿纵向的变化规律。该方法可为道岔直道岔钢轨损伤检测、导波频率选择和模态识别提供理论依据。然后结合不同位置截面的模态振型分析色散特性沿纵向的变化规律。该方法可为道岔直道岔钢轨损伤检测、导波频率选择和模态识别提供理论依据。