Nonlinear frequency mixing of ultrasonic waves for sensitive evaluation of closed defects

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04235
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Kyoto University
• Principal Investigator: BIWA Shiro 京都大学, 工学研究科, 教授 (90273466)
• Co-Investigator(Kenkyū-buntansha): 石井 陽介 豊橋技術科学大学, 工学(系)研究科(研究院), 助教 (70781706)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 機械材料・材料力学 / 超音波 / 非破壊評価 / 密着界面 / 周波数ミキシング / 高調波

Outline of Final Research Achievements

The nonlinear frequency mixing phenomenon of ultrasonic waves at contacting interfaces of solid bodies has been studied theoretically and experimentally. Namely, the frequency mixing and the harmonic generation phenomena have been analyzed theoretically based on a nonlinear spring-type interface model to elucidate the influence of the frequencies and angles of the incident waves and the linear and nonlinear parameters of the interface. Some qualitative features obtained by the analysis have been confirmed by the experiments for the contacting interface between two aluminum alloy blocks. Furthermore, the frequency mixing due to the material nonlinearity as well as the linear/nonlinear behavior of ultrasonic waves at closed defects have been studied. This study has provided some basic findings related to the nondestructive evaluation of closed defects using the frequency mixing characteristics.

Free Research Field

固体力学

Academic Significance and Societal Importance of the Research Achievements

本研究では密着界面における超音波の周波数ミキシングや高調波発生に関して非線形界面モデルに基づく理論解析および実験的検証が行われ、密着界面の線形・非線形パラメータがこれらの非線形超音波特性に与える影響が明らかになるなど、学術的に興味深い成果が得られた。本研究は周波数ミキシングを密着界面型欠陥の非破壊評価に適用するための基礎的検討と位置づけられ、本研究をさらに発展させることで各種の輸送機やプラントの構造健全性を確保するための非破壊欠陥評価法の充実につながることが期待できる。