Research on the quantitative measurement of elastic/plastic properties for the ultrasonic wave using laser probing method

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04404
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21030:Measurement engineering-related
• Research Institution: Akita University
• Principal Investigator: Imano Kazuhiko 秋田大学, 名誉教授, 名誉教授 (60125705)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: レーザープローブ法 / 残留応力 / 有限要素法 / モード解析 / レーリー波 / Lamb波 / セナルモン法 / 位相測定

Outline of Final Research Achievements

A new method for detecting or visualizing the inner-residual stress or defects was established by using laser probing method. Moreover, the acoustic information of small size around 20 μm which is not acquired from amplitude of ultrasound has been acquired. In addition, the real time visualization method and system for propagation of ultrasound, longitudinal wave Rayleigh wave and Lamb wave, in the water, glass and acrylic resin samples have been constructed and demonstrated. Quantitative evaluation of the ultrasonic sound pressure propagating in the sample has also been achieved. Although it was unplanned, it was also possible to detect nanometer-order non-uniformity in the vibration surface of the piezoelectric transducer. These results described above expected as the new evaluation method in the nondestructive testing. The proposed system and method have the academic meaning, especially in the sustainability of many social structures.

Free Research Field

超音波工学

Academic Significance and Societal Importance of the Research Achievements

レーザー光をプローブとして固体中の残留応力や欠陥を音波の伝搬に影響を与えずに測定する方法を確立できた。特に音波の位相に着目し、振幅情報からでは得られない微小領域の情報を明確に観測する方法を確立できた。また、音波の可視化法、特に、薄板状試料の形状の変化によって音波が板波（レイリー波、Lamb波）のモード変化を伴いながら伝搬する様子を可視化し,これらの結果を検証するための有限要素解析法の開発を行った．また，透明物質中を伝搬する音波の応力をセナルモン法により定量的に観測する方法の開発も行った。この成果は学術的な意義とともに材料や構造物の新しい検査法として期待でき、社会的な意義も大きいと考えられる。