Three-Dimensional Reconstruction of Partially Conductive Cracks from ECT Response Signals

This paper presents a novel approach for diagnosis of real cracks from two-dimensional eddy current testing signals by means of a stochastic method, such as tabu search. A new testing probe driving uniformly distributed eddy currents is employed for the inspection. Three spatial components of the perturbation field due to partially conductive cracks are sensed as the response signals in order to enhance information level of the inspection. The signals are simulated by a fast forward FEM-BEM solver using a database. Two crack models are proposed for the inversion: a crack with cuboid shape and a crack with more complex shape. In the both cases, the cracks have uniform conductivity. The length, depth, width and conductivity of the crack are unknown in the inversion process. Numerical results of the 3D reconstruction of partially conductive cracks from simulated 2D signals with added noise are presented and discussed.