Semi-analytical modeling of an eddy current imaging system for the characterization of defects in metallic structures

In this paper, the authors report on the implementation of a simplified and computationally efficient electromagnetic modeling of the interactions that take place between an eddy current imaging device and a metallic assembly, in the context of the non destructive evaluation of defects in metallic parts. The model is implemented in the case of the evaluation of a millimetric defect buried in a three plate aluminum assembly, for eddy current frequencies ranging from 300Hz to 3kHz. The model is validated against experimental data in terms of two-dimensional distributions of the computed magnetic field, as well as in terms of modulus and phase of the magnetic extrema observed in the images, in the whole frequency range. The obtained result provides promising prospects for the use of such model for the automatic characterization of defects in the context of the eddy current imaging of metallic parts.