FEM Technique for Modeling Eddy-Current Testing of Ferromagnetic Media With Small Skin Depth

The modeling of eddy-current testing problems, by means of finite elements, requires us to carefully consider the skin effect. When the material to inspect has a small skin depth compared with the other dimensions of the problem, which is a typical situation in the case of ferromagnetic media, the classical FEMs can become unsuitable in terms of mesh quality or computation time. In this paper, the overlapping FEM is implemented to efficiently consider the skin effect. 3-D problems are studied and the validity of the proposed approach is shown.