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为了满足铁路检测技术发展需要,针对严重影响着铁路运行安全的钢轨踏面剥离掉块缺陷,设计了一种全新的采用激光激发超声波和电磁超声接收超声波的钢轨踏面剥离掉块缺陷检测系统。通过该系统对钢轨试样进行扫查检测,可以精确的检测出钢轨踏面不同尺寸的模拟剥离掉块缺陷。通过小波阈值去噪获得了高信噪比的检测信号,通过频谱分析得到了剥离掉块缺陷对超声频谱特性的影响,为缺陷进一步识别提供了参考。通过实验和信号分析表明,设计的系统可以实现对钢轨踏面不同尺寸剥离掉块缺陷的完全非接触、高精度检测。
In order to meet the needs of the development of railway inspection technology, a new defect detection system of rail tread peeled off using laser-excited ultrasonic and ultrasonic ultrasonic was designed in order to peel off the defects on the rail tread which seriously affect the railway operation safety. Through the system of scanning test rail specimens, can accurately detect the rail tread different sizes of simulated peel-off defects. The detection signal of high signal-to-noise ratio (SNR) was obtained by wavelet threshold denoising, and the effect of peeled off defects on the ultrasonic spectrum was obtained by spectrum analysis, which provided a reference for the further identification of defects. The experimental and signal analysis shows that the designed system can achieve complete non-contact and high-precision detection of peeled off defects of different sizes on the rail tread.