Research on guided wave propagation characteristics in turnout rails with variable cross-section

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. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This paper introduces a method for analyzing the guided wave propagation characteristics of the turnout straight switch rail, and verifies its effectiveness through finite element simulation and field experiments. Results show that the dispersion characteristics of the rail change slowly along the longitudinal direction, proposing a three-dimensional dispersion surface and analyzing the mode shapes of the cross section at different positions.