基于同步提取变换的钢轨踏面裂纹电磁超声表面SH波B扫成像检测研究  

Study on B-Scan Imaging Detection of Rail Tread Crack with Surface SH Wave EMAT Based on Synchroextracting Transform

作　　者：钟芳桃 石文泽[1,2] 卢超 陈振华[1] 陈果 董德秀[4] ZHONG Fangtao;SHI Wenze;LU Chao;CHEN Zhenhua;CHEN Guo;DONG Dexiu(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China;State Key Laboratory of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;Jiangxi Provincial Key Laboratory of Numerical Simulation and Simulation Technology,Gannan Normal University,Ganzhou 341000,China;AECC Shenyang Liming Aero-Engine Co.,Ltd.,Shenyang 110043,China)

机构地区：[1]南昌航空大学无损检测教育部重点实验室,江西南昌330063 [2]中科院声学研究所声场声信息国家重点实验室,北京100190 [3]赣南师范大学江西省数值模拟与仿真技术重点实验室,江西赣州341000 [4]中国航发沈阳黎明航空发动机有限责任公司,辽宁沈阳110043

出　　处：《铁道学报》2023年第6期96-105,共10页Journal of the China Railway Society

基　　金：国家自然科学基金(12064001,52065049,51705231);江西省主要学科学术和技术带头人培养计划(20204BCJL22039);江西省自然科学基金(20192ACBL20052);江西省工程技术研究中心计划项目(20192BCD40028)。

摘　　要：钢轨踏面在车轮的重复载荷作用下,极易产生滚动接触疲劳裂纹,并从轨头向下扩展,甚至导致断轨等重大安全事故,因此开展钢轨踏面裂纹高效准确的无损检测方法研究具有重要意义。对于钢轨轨头有限截面非规则几何体,无法采用解析法求解其频散曲线,采用Floquet-Bloch边界的有限元特征频率法,求解钢轨轨头类水平剪切导波频散曲线,在频散曲线的基础上,分析并确定电磁超声表面水平剪切波换能器的最佳检测频率。建立表面水平剪切波在含踏面裂纹钢轨轨头的传播有限元模型,研究表面水平剪切波在不同角度、深度的踏面裂纹上的反射及透射规律。为实现快速的钢轨踏面裂纹B扫成像检测且得到高信噪比的检测结果,实验对比同步提取变换和同步压缩变换对钢轨踏面检测回波的噪声滤除能力。结果表明:对单次检测回波应用同步提取变换消噪处理后,信噪比提高13.73 dB,比单次采集信号经同步压缩变换处理后的信噪比高4 dB。将同步提取变换用于钢轨踏面导波B扫成像检测,可以减小同步平均次数以满足快速检测的要求。Under the action of the repeated load of the wheels,the rail tread is prone to rolling contact fatigue cracks,which can extend downwards from the rail head,even leading to major safety accidents such as broken rail.Therefore,it is of great significance to develop an efficient and accurate non-destructive detection method for rail tread cracks.For the railhead with finite cross-section irregular geometry,the analytic method can not be used to solve the dispersion curve.The Floquet-Bloch boundary finite element characteristic frequency method was used to solve the dispersion curve of shear horizontal waves of the rail head.Based on the dispersion curve,the best detection frequency of the surface SH wave electromagnetic ultrasonic transducer was analyzed and determined.A finite element model was established for the surface shear horizontal wave propagation in the rail head with tread cracks to study the reflection and transmission patterns of surface SH waves on tread cracks with different angles and depths.To achieve rapid B-Scan imaging detection of rail tread cracks and obtain high signal-to-noise ratio detection results,an experimental comparison was conducted for the noise filtering ability of synchroextracting transform and synchrosqueezing transformon rail tread detection echoes.The results show that after applying synchroextracting transform denoising processing to the detection echo with no synchronous average,the signal-to-noise ratio is increased by 13.73 dB,which is 4 dB higher than the signal-to-noise ratio of the detection echo with no synchronous average but precessed by synchrosqueezing transform.The use of synchroextracting transform for guided wave B-Scan imaging detection of rail treads can reduce the number of synchronization averages to meet the requirements of rapid detection.

关 键 词：钢轨踏面裂纹 表面水平剪切波 有限元特征频率法 同步压缩变换 同步提取变换 

分 类 号：TH878[机械工程—仪器科学与技术] TB552[机械工程—精密仪器及机械]