Ultrasonic Evaluation Method for Bolt Fastening with Adhesive Agent

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06377
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Measurement engineering
• Research Institution: Akita University
• Principal Investigator: Fukuda Makoto 秋田大学, 理工学研究科, 講師 (50507671)
• Research Collaborator: Yoshida Shun ; Iida Tatsuma ; Fujita Ikumi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 超音波 / 非破壊検査 / ボルト / 反射係数 / Lamb波 / 2次高調波

Outline of Final Research Achievements

Experiment using reflection coefficient using continuous wave ultrasonic wave and second harmonic ultrasonic wave for the purpose of evaluation method of bolt fastening state with adhesive agent using ultrasonic wave. In the reflection coefficient method, it was confirmed that the reflection coefficient decreased with the increase of torque. On the other hand, the transmission coefficient was almost no change in the torque. Therefore, further study is necessary. In the method using the second harmonic, we proposed the method using the Lamb wave of Lame mode assuming that the flat plate is bolted. Although the possibility of crack detection could be shown, the second harmonic components in bolt fastening could not be detected.

Free Research Field

超音波工学

Academic Significance and Societal Importance of the Research Achievements

超音波による新しいボルト締結法は，簡易で精度良く，かつ，全数検査を可能とすることを目標としており，ボルトの緩みや破断による事故を未然に防ぐことが目的である．高度経済成長期に作られた高架や橋梁などの維持管理が多く必要となっている時期であり，作業人員の確保や熟練度による評価のばらつきなどが課題として挙げられている．本研究は締結済のボルトの検査や新たに締結するボルトの管理の一助になると期待できる．