3D reconstruction of surface cracks using bi-frequency eddy current images and a direct semi-analytic model

Abstract

We propose a method for reconstructing 3D surface cracks in metallic parts form eddy current (EC) images. To do so, we use a semi-analytic direct model for representing the interactions between EC and a crack. In order to cope with the inverse problem cons isting in reconstructing 3D cracks, we propose the use of a genetic algorithm based on the computation of bi-frequency EC images. Numerical experiments are carried out in order to analyze the performance of the reconstruction method for different signal to noise ratios. Moreover, the results obtained with a bi-frequency genetic algorithm are compared to those obtained with a mono-frequency algorithm.