周方向等角入射横波による円管内面軸方向欠陥の非破壊検査

概要

論文の詳細を見る
A defect inspection and sizing technique for the corrosion of thin-walled pipes with circumferential SV waves is extended to precise sizing of defects at inner surface. The conventional angular transducers placed on the outer surface of pipes excite SV waves of different refraction angles depending on the incident position. Thus, refracted SV beams diverge markedly, which results in non-uniform distribution of the wave amplitude throughout the cross section of the pipe. In this study, a special angle beam transducer that excites SV wave of the same refraction angle in the pipe wall is designed and applied to sizing of inner axial defects. With this transducer, the wave amplitudes passing through the defects are nearly proportional to the defect depth with a fixed width. The transducer also excites circumferential guided waves; therefore, the modes and group velocities are measured with a laser ultrasonic detector of an ultra broadband. The use of the circumferential guided waves of various modes gives us more information of defect features.
社団法人日本機械学会の論文
2004-09-25