Numerical approach to inverse problem of crack shape recognition based on the electrical potential method [of NDT]

The authors present a novel scheme for the shape identification of a crack included in a conducting solid based on the measurement of electrical potential distribution. The scheme is based on an inverse governing equation for space variables as a function of electrical potential and stream function, which is obtained from the Laplace equation for the electrical potential and the stream function by interchanging dependent and independent variables. Numerical simulations are demonstrated for a tube with a single crack and multiple cracks. A system matrix is used to reduce the ill-posedness of the problem when predicted shapes are compared with known defect shapes, and fairly good agreement is obtained