This article presents a numerical model dedicated to the computation of a quasi-static field induced by a 3-D eddy current probe in unidirectional composite material presenting delamination. The specimen is homogeneously anisotropic and the flaw is represented by a local deformation in the planar geometry. The curvilinear coordinate method (CCM) is used to solve Maxwell’s equations in covariant form. Based on the Fourier modal method, the semi-analytical approach consists of presenting the electromagnetic field components as eigenmode expansion in a new non-orthogonal coordinate system fitting the geometrical perturbation. Then, interface conditions can be analytically included in order to evaluate the unknown amplitude of eigenmodes. To take into account the contribution of lower interfaces, a recursive and stable scattering matrix algorithm is implemented. The numerical validation shows a good agreement between simulation results and finite element (FE) data.

中文翻译：

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3-D涡流探头在粗糙界面各向异性材料中产生的准静态磁场的半解析计算

本文提出了一个数值模型，专用于计算在存在分层的单向复合材料中由3-D涡流探头引起的准静态磁场。样品是均匀各向异性的，并且缺陷由平面几何形状中的局部变形表示。曲线坐标法（CCM）用于协变形式求解麦克斯韦方程组。基于傅立叶模态方法，半解析方法包括将电磁场分量作为本征模展开式呈现在适合几何扰动的新非正交坐标系中。然后，可以分析地包括界面条件，以便评估本征模的未知振幅。考虑到较低接口的贡献，实现了递归和稳定的散射矩阵算法。数值验证表明，仿真结果与有限元（FE）数据之间具有良好的一致性。