ABSTRACT

This work is devoted to studying a direct and inverse scattering problem for a magnetoelastic layer having a defect, in the frame of the electromagnetic theory. In terms of the displacement field over the defect's contour, a coupled system of boundary integral equations is formulated, for magnetically permeable and impermeable defects. To identify the position and size of the defect, an efficient numerical algorithm is developed by using the quasi-Newton iterative method. In order to check the influence of the magnetic field upon the scattering waves from the layer, a series of numerical examples is presented with different noise levels. The results showed that the magnetic field has a sensitive effect on the identification process when the external magnetic field increases, especially for the materials having a high magnetic permeability factor ${\mu }_r$. Also, a special inverse problem for predicting the external applied magnetic field, upon a copper layer having a defect with various sizes, has been performed.

摘要

这项工作致力于在电磁理论的框架内研究具有缺陷的磁弹性层的直接和逆向散射问题。根据缺陷轮廓上的位移场，针对导磁和不可渗透缺陷制定了边界积分方程的耦合系统。为了识别缺陷的位置和大小，使用拟牛顿迭代法开发了一种有效的数值算法。为了检查磁场对来自层的散射波的影响，提供了一系列具有不同噪声水平的数值示例。结果表明，当外部磁场增加时，磁场对识别过程有敏感作用，${\mu }_r$. 此外，在具有各种尺寸缺陷的铜层上，已经执行了用于预测外部施加磁场的特殊逆问题。