任意形状缺陷漏磁检测的有限元前向模型

Research on Finite Element Forward Model for Magnetic Flux Leakage Testing of Arbitrary Shape Defects

漏磁检测简单高效,是一种广泛应用于各种铁磁性材料的无损检测技术。有限元法求解漏磁场计算准确,鉴于MATLAB建模具有很大的灵活性和可扩展性,基于MATLAB,建立了漏磁场的有限元模型,进行了模型验证。研究了矩形裂纹缺陷的宽度、深度、提离值对漏磁信号的影响。针对自由度为20的任意形状缺陷,实验中给出了4种不同形状缺陷漏磁场轴向分量、径向分量及磁感应强度分布云图,并分析了其特点,为降低有限元前向模型的计算代价提供了可能。

Magnetic flux leakage testing is simple and efficient. It is a kind of nondestructive testing technology which is widely used in all kinds of ferromagnetic materials. The finite element method is more accurate to solve the magnetic leakage field. In this paper, a finite element model for analysis of leakage magnetic field is established based on MATLAB and the model has been certificated, because there are more flexibility and extensibility based on MATLAB modeling. The influence of the width, depth and lift off value of the rectangular crack defects on the magnetic flux leakage signal is studied. In the experiment, as for arbitrary shape defect of 20 degree of freedom, axial component and radial component of magnetic flux leakage field and magnetic induction intensity distribution of 4 different kinds of defects are given. And its characteristics are analyzed. It may be possible to reduce the computational cost of finite element forward model.