直流電位差法による溶接部に存在する三次元き裂の形状評価

抄録

A high accuracy nondestructive procedure utilizing the direct current electrical potential method is proposed to evaluate the 3D shape of a crack in a welded plate. An elliptical embedded crack and a semi-elliptical surface crack on the back wall are evaluated on location, length and inclination of the crack. The change on electrical potential distribution due to the effect of both electrical and geometrical inhomogeneity of the weld is described, and the availability of the calibration method on the effect is verified for an embedded crack with a reinforcement. The evaluation procedure is carried out by comparing the measured values of the electrical potential distribution, which are corrected by utilizing the calibration method, with the calculated distribution in accordance with optimization method. The availability of the presented procedure is verified by experiments using stainless steels.