Lamb wave generation to detect damage for a wide area of an aircraft using laser-induced plasma

2016 Fiscal Year Final Research Report

• Project/Area Number: 26630080
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Dynamics/Control
• Research Institution: Shibaura Institute of Technology
• Principal Investigator: Hosoya Naoki 芝浦工業大学, 工学部, 准教授 (40344957)
• Co-Investigator(Renkei-kenkyūsha): Kanda Atsushi 独立行政法人宇宙航空研究開発機構, 航空本部, 主任研究員 (40358693)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 損傷検知 / 航空機構造 / Lamb波 / レーザー誘起プラズマ / レーザーアブレーション / 衝撃波

Outline of Final Research Achievements

This study aims to realize a non-contact damage detection system for large objects such as an aircraft. Irradiating the target surface with a high-power Nd: YAG pulse laser induces LA and generates Lamb waves. Spectrum analyses on the Lamb waves generated by LA reveal that the Lamb waves contain a broad range of frequency components up to several hundred kHz. The LA-generated Lamb waves have amplitudes several hundred times larger than those generated by conventional laser ultrasonic Lamb waves, improving the SN ratio. The improved SN ratio reduces the required number of measurements, resulting in a shorter measurement time. Thus, the proposed method can be applied to detect damage on a large area of a large structure. The LA-generated Lamb waves were applied to detect a through crack, which was artificially made to simulate damage. Damage causes the reflection and amplitude of the Lamb wave to change, demonstrating the effectiveness of LA-generated Lamb waves to detect damage.

Free Research Field

機械力学