A method of analytically modelling electromagnetic fields is applied in eddy current NDE. The test case examined involves an axisymmetric ferrite-cored coil over a conducting half-space. The boundary value problem is formulated in terms of the magnetic vector potential, which is expanded in series of orthogonal eigenfunctions, the discrete eigenvalues of which are computed as zeros of appropriate functions. Expressions are derived for the impedance of the coil and the induced eddy current density. The validity of the model is tested with a 2D-FEM code.
展开▼
