Eddy-current analysis of a conductor with a crack by line integral equations with loop electric and magnetic currents as unknowns

It is difficult to calculate eddy currents induced in a conductor with a crack by the surface integral equations because its adjacent edges and corners, where the equations become singular, are close, and moreover, the equations become ill-conditioned in cases where the crack gap is narrow. In this paper, we propose a method employing line integral equations with loop electric and magnetic currents as unknowns fully utilizing the boundary conditions of the surface electromagnetic fields. Solving eddy-current problems and comparing the results with those by FEM, we study how to calculate accurately the eddy currents induced in a conductor with a crack