变温环境下超声导波钢轨结构健康监测技术研究

Research on Rail Structure Health Monitoring Technology Based on Ultrasonic Guided Wave in Variable Temperature Environment

在应用超声导波进行钢轨结构健康监测时,温度变化会导致钢轨的导波特性发生改变,从而影响监测结果的准确性。主要分析温度对钢轨导波波速的影响,提出采用3次样条插值在时域拉伸信号,实现导波波速的补偿,将归一化能量均方差作为选择最佳拉伸因子的准则及钢轨伤损判断的标准,避免导波信号幅值变化对监测结果的影响,通过对实验数据的处理验证算法的有效性,并在呼和南站重载线路进行锯轨演示试验,为变温环境下的钢轨结构健康监测提供了技术基础。

When using ultrasonic guided waves to monitor the health of rail structure,the temperature change will lead to the change of the guided wave characteristics of the rail,which will affect the accuracy of the monitoring results.This paper mainly analyzes the influence of temperature on guided wave velocity of rail,and proposes to use the cubic spline interpolation to stretch the signal in time domain to realize the compensation of the guided wave velocity.The normalized energy mean square error is used as the criterion for selecting the best tensile factor and the criterion for judging the damage of the rail,which avoids the influence of the amplitude change of the guided wave signal on the monitoring results,and the effectiveness of the algorithm is verifi ed by processing the experimental data.In addition,a rail sawing demonstration test was carried out on the heavy-haul line of Hohhot South Station.It provides a technical basis for the health monitoring of rail structure in variable temperature environment.