动生涡流无损检测的二维稳态解析模型

2D Static Analytical Model for Motion Induced Eddy Current Nondestructive Testing

动生涡流无损检测方法在金属材料的高速检测中有较好的应用前景,但目前仍缺少有效的解析模型。为了解决这一问题,应用傅里叶变换建立了基于导线激励的动生涡流检测解析模型。首先基于麦克斯韦方程组推导出空气和导体中的电磁场控制方程,然后引入傅里叶变换求得空间频域通解,再根据磁场边界条件求得空间中磁场的分布以及导体试件中涡流的分布。最后将解析结果和有限元仿真结果对比,验证解析模型的正确性,并基于解析模型分析了导体运动速度对涡流分布的影响。

Motion induced eddy current nondestructive testing has good application prospect in high-speed inspection of metals.However,there is no effective analytical model at present.To solve this problem,an analytical model for motion induced eddy current testing by Fourier transform was established.Firstly,the governing equations of electromagnetic field in air and conductor were derived based on Maxwell equations.Then,the general solution in spatial frequency domain was obtained by introducing Fourier transform.Then according to the boundary conditions of magnetic field,the distribution of magnetic field in space and eddy current in conductor specimen were obtained.Finally,the analytical results were compared with the finite element results to verify the correctness of the analytical model.The influence of conductor velocity on the distribution of eddy current was analyzed based on the analytical model.