Finite-Element Model for Simulation of Ferrite-Core Eddy-Current Probe

The finite-element method is widely used in modeling eddy-current phenomena. However, its application in eddy-current nondestructive testing involving probe motion requires remeshing for each coil position. Remeshing is not only cumbersome but also a major source of computational noise. We have used the reduced magnetic vector potential formulation to model an air-core probe scan without remeshing the coil in different positions. In this paper, we present a method to model the scanning of ferrite-core probe. With this method, finite-element meshes for the test sample and the ferrite core are generated separately. The coil is not meshed. The magnetic field and magnetic vector potential due to the coil are evaluated analytically. An iterative but fast procedure is used to update the total field. The method is simple, flexible, accurate, and efficient.