Finding a Crack’s Position and its Parameters on the basis of Non-Destructive testing, using Eddy Currents

Abstract

The purpose of this paper was to find the geometry of a crack within a conductive plate and its parameters, on the basis of non-destructive testing, using eddy currents. The input data represents the measured values of magnetic flux density within the centre of the excitation coil. The position of a crack can be determined by taking into consideration any change in the magnetic flux density between the measured points. The depth and width are determined through the use of a finite-element model. These calculations are the basis for determining a function that explains how magnetic flux density changes if the depth or width has changed. After wards, through the Newton-Raphson iterative procedure using the finite-element method calculation results, the crack depth and width can be obtained. The suitability of the presented method was verified by the experimental example.