基于振动模态分析的钢轨中超声导波传播特性数值计算方法

摘要

Aiming at difficult problems to solve the dispersion characteristics of ultrasonic guided wave in complex waveguide structures,such as,rails,here the vibration modal analysis method was used to extract the propagation characteristics of ultrasonic guided wave.Based on the principle that vibration characteristic frequencies and wave solutions can convert each other,the solutions of characteristic frequencies obtained with vibration modal analysis were converted into wave solutions,and then the dispersion characteristics of rails were extracted.Deformation information was gained from vibration analysis of a structure,and with it the wave structure of ultrasonic guided wave was calculated.The dispersion information and wave structure information of lower order modes of ultrasonic guided wave were analyzed,the modal type of ultrasonic guided wave and its frequency range were selected,all of them provided a theoretical support for designing special ultrasonic guided wave sensors and measuring tests.%针对钢轨等复杂异型波导结构中超声导波频散特性难于求解的问题，通过振动模态分析提取出钢轨中超声导波传播特性。基于振动特征频率和波动解互相转化的原理，将振动模态分析获得的特征频率解，转换成波动解，进而提取出钢轨的频散特性。同时，还可以由结构振动分析中获得的变形信息，计算出超声导波的波结构。通过对计算出的钢轨中低阶超声导波模态频散特性和波结构分析，选择出适合钢轨无损检测的超声导波模态类型和频率范围，为后续专用超声导波传感器设计和检测实验提供理论支持。