Calculation of eddy current testing probe signal with global approximation

Global approximating function sets applicable to the solution of the integral equation used to calculate an eddy current testing probe signal are proposed. Rectangularly-shaped cracks normal to the surface of plate specimens are considered. The approximating functions are orthogonal harmonic functions satisfying the boundary conditions at the edges of the crack. The calculations using the proposed approximating functions are fast, numerically stable and provide a robust alternative to other methods used in the literature. A number of numerical examples are shown for illustration and discussed