冲击回波声频法在高速铁路CRTSⅢ型轨道板脱空检测中的应用

Nondestructive Testing Technology of High Speed Railway CRTS Ⅲ Type Track Board Based on Impact Acoustic Echo Method

现阶段板式无砟轨道CRTSⅢ型轨道板已成为我国高铁轨道技术的主流,但受施工及自然因素的综合影响,容易出现CRTSⅢ型轨道板与自密实混凝土调整层层间脱空等问题.现有可行的检测方法较少,且无法高效准确地找出脱空位置.基于高铁线下层状结构,采用冲击回波声频法采集信号,最大熵值法频谱分析方法对采集的信号进行分析,提取冲击弹性波在轨道板层间传递过程中的反射能量特征,实现对轨道板脱空的有无及位置的辨识,同时介绍了信号接收装置使用音频传感器相对于传统加速度传感器的优势,以及验证了冲击回波声频法在轨道板脱空检测实际应用中的实用性.

The ballastless track CRTS Ⅲ type board has become the mainstream of the high-speed rail technology in our country, but the comprehensive construction technology and natural factors cause the voids behveen the CRTS Ⅲ type track Iwarcl and self-compacting concrete adjustment layer. There are few available detection methods,and it is not efficient and accurate to find the empty position. Based on its layered structure, the spectrum signal is collected by the Impact Acoustic Echo method and analyzed by the Maximum Entropy Method, and the characteristics of reflected energy of impact elastic wave in the transfer process between track plates are extracted. Tlie position of track Iwarcl defects will be detected, and the advan-tages of audio sensor in signal receiver compared with traditional acceleration sensor are introduced. The practicability of the Impact Acoustic Echo method in the practical application of track plate cavity detection is verified, too.