Analytical Model of Perturbed EMF in a Transmit-Receive Coil System Due to Thin Flaws

This work proposes a model based on the semianalytical boundary element method (BEM) to predict the perturbation of the voltage induced in an eddy current coil due to narrow opening flaws that are usually encountered in eddy current nondestructive tests. The modeling is performed for rectangular narrow opening flaws that are located on the surface of an aluminum plate of finite thickness. The excitation to the coil varies time harmonically and the BEM results are corroborated by experiments performed in a controlled environment in the laboratory.