Efficient inspection for piping in 50 meter long using a ultrasonic guided wave

Research Project

Project/Area Number	16K05979
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Materials/Mechanics of materials
Research Institution	The University of Tokushima
Principal Investigator	NISHINO Hideo 徳島大学, 大学院社会産業理工学研究部(理工学域), 教授 (50316890)
Project Period (FY)	2016-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000) Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	非破壊検査 / 超音波 / ガイド波 / 超音波非破壊計測 / 超音波計測 / 機械工学
Outline of Final Research Achievements	Purpose of this research is to improve the guided wave method of the defect inspection much more efficiently by locating noncontact-scanning-type receivers near defects. It was confirmed that the method was able to detect the defect located 55-meter apart from guided wave transmitter. In above case, the amplitudes of the defect signals were observed around half compared to the normal case but it was easy to discriminate them because the receivers were located near the defects. In addition to above, the mechanism of the reflection at the defect (discontinuity in piping) was investigated by means of the mathematical model proposed by ourselves and the experimental results. The mathematical model shows well the phenomena of the experimental results.
Academic Significance and Societal Importance of the Research Achievements	学術的意義：ガイド波は効率的な検査手法であるが，減肉サイズと検出信号に明瞭な相関関係がなく，検査定量性が低いことが問題であった。ここでは欠陥反射における数学モデルを提唱しモード変換を伴う反射メカニズムを解明し査読付き論文として掲載を果たしている。社会的意義：本研究は，産業インフラや社会インフラに無数に存在する重要な構造物である中空丸棒を，効率的に計測できる超音波ガイド波による検査技術をさらに効率化するための研究を取り扱ったものである。結果として，５５メートル程度の検査の実現可能性を示すことができている。一方で，移動性の優れたガイド波検出装置の開発が課題である。