電位差法による埋没き裂と裏面き裂の区別と定量評価

抄録

A D. C. Electrical potential method has been developed to discriminate between an embedded crack and a surface crack on the back wall and then to evaluate their positions and sizes. The method consists of the following procedures : (1) Calculate two parameters, ΔΦ_max and A, from a measured curve of potential difference distribution, whereΔΦ_max is the maximum potential difference and A is an area characterizing the distribution. (2) Assuming a surface crack, calculate two values of its length fromΔΦ_max and A. (3) If these two values are equal to each other, then the crack is discriminated as a surface crack. ( 4 ) In the case of an embedded crack, calculate the length from A and the depth fromΔΦ_max. It has been found from experiments that the proposed method is useful for discriminating and sizing embedded cracks and surface cracks on back walls.