高铁钢轨涡流无损探伤技术的高效电磁建模方法研究

High-speed railway occupies a pivotal position in our transportation system. In order to ensure the security of high-speed railway, it is especially important to research on non-destructive evaluation technique since the safety of rail is the basis of running locomotive and rolling stock. Compared to other testing techniques, eddy current testing is suitable for detecting surface flaw of high-speed rail with advantages of high sensitivity, efficient detection, no coupling agent and remote sensing. Since the principle of eddy current testing is electromagnetic induction, it is significant and essential to research on electromagnetic modeling and simulation technique of eddy current testing for flaw detection of rail. This project focuses on electromagnetic modeling and efficient simulation method of eddy current non-destructive evaluation technique for high speed railway. The integral equation model is proposed and moment method is used to solve the problem accurately. Then, research on electromagnetic mechanism, analytical model and numerical solution of eddy current source. Hybridization of multi-level adaptive cross approximation, adaptive sampling and parallel computation technique is applied to improve the efficiency. This hybrid simulation system is able to provide accurate and efficient results of electromagnetic properties of rail, resulting in essential theoretical basis and simulation database for development of eddy current non-destructive evaluation of rail in high-speed railway.

高速铁路在我国交通运输体系中占据非常重要的地位，钢轨是高铁机车车辆运行的基础，研究钢轨的无损探伤技术对保障高铁运营安全尤为重要。与其它探伤技术相比，涡流探伤具有灵敏度高、探测速度快、不需要耦合剂、无需接触等特点，适合探测钢轨表面的接触性损伤。由于涡流探伤的物理机理是电磁感应，因而研究相应的电磁模型和仿真技术，是涡流探伤技术研究中的重要环节，具有重要意义。本项目主要研究高铁钢轨涡流探伤的电磁建模和高效仿真方法，提出涡流探伤的积分方程模型，并采用矩量法对模型进行精确求解。与此同时，研究涡流激励源的电磁机理，并提出激励源的解析和数值模型。为了提升计算效率，提出采用多层ACA技术、自适应采样技术、并行技术构造混合计算平台，实现对高铁钢轨电磁特性的精确、高效仿真，为高铁钢轨涡流探伤技术的发展提供理论依据和仿真数据。