Damage evaluation of heat-resistant composites for aircraft engines at elevated temperature using novel fiber-optic sensor-based AE detection method

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K13920
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: The University of Tokyo
• Principal Investigator: Yu Fengming 東京大学, 生産技術研究所, 特任研究員 (50814307)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 高温環境 / 光ファイバセンサ / 再生FBG / アコースティックエミッション / 超音波 / 耐熱性複合材料

Outline of Final Research Achievements

Heat-resistant composites are expected to be used for aircraft engines. For their practical application, it is necessary to understand the damage progress in those materials at elevated temperatures. To clarify the damage progress at high temperatures, we proposed a novel remote AE measurement method with a fiber-optic Bragg grating sensor. This method enables the successful real-time response to actual damage-induced AE signals during material tests at temperatures of up to 1000 ℃. We verified that the testing results are useful to elucidate the relation between the damage progress and the fracture strength at different temperatures.
Furthermore, the AE measurement is also expected to be used as a structural health monitoring technique to monitor damage progress while the composite-made structure is in operation. For this purpose, we have also developed a regenerated FBG sensor that can be directly installed in high-temperature environment and succeeded to receive ultrasonic waves.

Free Research Field

工学

Academic Significance and Societal Importance of the Research Achievements

1000 ℃の高温環境下で使用可能な高感度な光ファイバAEセンシング技術の確立は、世界で初めての試みである。さらには、高温環境での複合材料における損傷進展挙動の解明に、本技術が有効であることを証明できた。したがって本研究は、航空宇宙分野や複合材料工学において、学術的新規性と工業的有用性が高いと考えている。
本研究で構築した技術は、今後、耐熱性に優れた軽量複合材料の効率的な開発と、その使用時の信頼性確保に貢献出来できると考えており、航空機エンジンの省エネルギー化に必要な、さらなる軽量化と低燃費化の推進に役立つことが期待できる。