An inverse analysis for crack identification in eddy current NDT of tubes

This paper presents an inverse analysis for crack identification in eddy current nondestructive testing of tubes. The finite element modeling of axisymmetric eddy current phenomena is based on the formulation of the energy functional with the magnetic vector potential. An optimization algorithm in the inverse process employs the objective function expressed in terms of the impedance change of a differential probe which consists of two coils. The proposed method is applied to a simple axisymmetric model with a crack made arbitrarily. >