钢轨踏面的空气耦合超声检测方法*

该文针对钢轨踏面浅表面裂纹提出非接触空气耦合超声类瑞利波的检测方法。首先利用半有限元法求解了CHN60型钢轨的振动模式,抽出了钢轨轨头踏面的振动模态结构和频散曲线,并搭建实验系统,根据Snell法则和声源在空气中的声场分布确定了检测参数,最后从理论和实验两方面着手对钢轨踏面浅表面裂纹的有无及裂纹大小进行了实验分析和数值计算,其结果非常吻合,证明了空气耦合超声导波检测方法的可行性和可靠性。

Air coupled ultrasonic testing method for rail tread

In this paper, a non-contact air-coupled ultrasonic Rayleigh wave detection method is proposed for shallow surface cracks on rail treads. Firstly, the vibration mode of CHN60 rail head is solved by semi-finite element method. The vibration mode structure and dispersion curve of the rail head tread are extracted, and an experimental system is built. The detection parameters are determined according to Snell rule and the sound field distribution of sound source in the air. Finally, the experimental analysis and numerical calculation of cracks on the shallow surface of rail tread are carried out from both theoretical and experimental aspects. The results are in good agreement, which prove the feasibility and reliability of the air-coupled ultrasonic guided wave detection method.