基于弹性波传播的高速道岔尖轨断轨识别

Identification of switch rail brakeage in high speed railway turnout based on elastic wave propagation

针对高速道岔尖轨断轨监测问题,开展基于弹性波传播的高速道岔尖轨断轨识别研究.采用显式有限元方法建立高速道岔弹性波传播特性分析模型,模型中考虑尖轨与基本轨密贴状态、滑床台板支承等约束条件,结合试验对该模型进行验证.研究不同激励频率、尖轨断轨位置及密贴状态等因素对高速道岔尖轨弹性波传播特性的影响.研究表明:在健康尖轨中,2 kHz和4 kHz弹性波能量集中,传播信号基本不受基本轨和滑床台等约束条件的影响;在断轨识别中,通过滑床台传播的信号衰减倍数大于10~9,通过尖/基轨密贴传播的信号对各个频率弹性波的断轨识别均存在显著影响;在密贴状况下,断轨位置与弹性波传播信号存在一定的关联.

The identification of high-speed switch rail break based on elastic wave propagation was analyzed aiming at the monitoring problem of high-speed switch rail break.The explicit finite element method was used to establish an analytical model for the elastic wave propagation characteristics of high-speed turnouts,in which the constraints such as switch closure and the support of the sliding bed platform were considered.The model was verified by experiment.The effects of different excitation frequency,fracture position of switch rail and the close-contact state on the elastic wave propagation characteristics of the high-speed turnout were analyzed.Results showed that the elastic wave energy of 2 kHz and 4 kHz was concentrated in the healthy rail,and the signal propagation was basically not affected by the constraints of stock rail and slide bed platen.In the process of broken rail identification,the signal transmitted by slide bed platen attenuated to above 10~9,and the signal transmitted by switch closure had significant influence of elastic waves of various frequencies.Broken rail position was related to the signal of elastic wave propagation under close contact.