基于复合电磁的高速轨道缺陷检测方法研究

Study on High-Speed Rail Defect Detection Method Based on Combination of EC and MFL Testing

钢轨表面和埋藏缺陷的检测与分类,对于保障铁路运输安全有着重要的意义。提出了一种将漏磁与涡流检测相结合的高速轨道缺陷检测方法,对表面和埋藏缺陷进行了识别与分类。设计了一种复合电磁检测探头,采用差分线圈同时检测涡流和漏磁信号。建立了复合电磁检测系统,在20~300 km/h速度下对高速铁路转台样例进行了检测。根据高频涡流更适用于表面缺陷的检测而直流漏磁能同时检测表面开口和近表面埋藏缺陷的特点,对涡流和漏磁的检测信号进行处理与对比,分别得到了表面和埋藏缺陷的信号。试验结果表明,该方法对钢轨样例上所有表面和埋藏缺陷都实现了检出与分类。

The detection and classification of rail surface and buried defects is of great significance to ensure the safety of railway transportation. In this paper, the classification method of surface and buried defects based on the combination of magnetic flux leakage(MFL) testing and eddy current(EC) testing is proposed. A composite electromagnetic detection probe is designed, in which the differential coil can detect EC and MFL signals simultaneously. A composite electromagnetic detection system is set up to detect high-speed rail turntable samples at 20–300 km/h. Based on the characteristics that high frequency EC signals can only detect surface defects and DC MFL can detect both surface and buried defects, the detection signals are processed and EC and MFL signals are obtained and compared. Experimental results show that this method can accurately detect and distinguish between surface and buried defects.