An alternative method for crack interaction in NDE of multiple cracks by means of potential drop technique

A procedure of calculating the crack interaction in NDE of multiple cracks by d.c. potential drop technique is newly developed. This method can be used when the distances between cracks are small or large. The equations obtained evaluate crack interaction for any case regardless of the distances between the cracks. A subregion containing m (=1,3,5,…,) cracks are considered. The potential drop of the middle crack for each subregion are considered for two successive cases ( m and m+2). The ratio of these two potential drops shows the effect of the first and last cracks of the subregion on the potential drop of the middle crack. The crack interaction is shown by the ratio of the potential drop of the middle crack to the potential drop of a single crack with the same depth and the same positions of potential probes. The equations showing the crack interaction are obtained based on the numerical analysis followed by an experimental validation.