Experimental Study of Three-Dimensional Identification of Surface Crack by Means of Direct-Current Electrical Potential Difference Method of Multiple-Point Measurement Type

抄録

A method for identification of a crack on the surface of material by means of direct-current electrical potential difference method of multiple-point measurement type was proposed and the related experiments were carried out to verify the method. The geometry of the crack was given by the two-dimensional location of the crack center, the surface and inward angles, the length and the depth of the crack. The experiments were carried out for metal plates with various surface cracks made by electric discharge machining. When most of the area of electric potential disturbance by the crack was included in the measurement area, the geometry of the crack was successfully evaluated by the proposed method based on the potential differences measured at multiple locations around the crack.