基于三维有限元法的漏磁场分析

Analysis of Magnetic Leakage Fields Based on 3D FEM

针对磁偶极子模型和二维有限元法在分析漏磁场过程中存在的不足,采用三维有限元分析漏磁场。根据麦克斯韦方程组和三维有限元分析原理建立了数学模型。利用数学模型对漏磁信号进行了仿真分析,得到了三维磁通密度矢量图和它的径向分量曲面图,直观地显示了缺陷附近漏磁场的特点。同时研究讨论了缺陷长度、检测路径位置和提离值对漏磁信号峰峰值的影响。为进一步对漏磁场的研究打下基础。

3D finite element method （FEM） was adopted to analyze the magnetic leakage fields （MLF） because of the drawbacks of magnetic dipole model and 2D FEM. The mathematical models for MLF were established based on the Maxwell＇s equations and 3D finite element theory. The models were used for simulating and analyzing MLF data sets. The vector plot of 3D magnetic flux and the surface plot for the radial component of magnetic flux density were obtained, which could show the feature of the MLF near defect expressly. The effects of the defect length, the lift-off and the path position on the peak-peak values for magnetic flux leakage signals were studied. It is the base for further studying on magnetic flux leakage inspection.