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Detection of contact-type failure of large-scale structure based on nonlinear wave modulation using multi-excitation using decentralized control

Research Project

Project/Area Number 20K14682
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 20010:Mechanics and mechatronics-related
Research InstitutionThe University of Shiga Prefecture

Principal Investigator

Tanaka Takashi  滋賀県立大学, 工学部, 講師 (60759273)

Project Period (FY) 2020-04-01 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2020: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Keywords超音波 / 非線形振動 / 損傷検出 / 自励駆動 / 固有振動 / 多点加振 / 分散制御 / 非線形 / 大型構造物 / 分散制御型多点加振
Outline of Research at the Start

疲労き裂や複合材料のはく離などの接触型損傷は,検出が困難な損傷である.接触型損傷を精度よく検出できる手法に非線形波動変調に基づく検出法が提案されている.この手法は,超音波の固有振動を利用することで,精度よく検出できる.一方で,大型構造物では,超音波の固有振動を励起することが困難である.本研究では,自励振動子の同期現象を利用した分散制御型多点加振により大型構造物の固有振動を励起する技術を開発し,自励駆動された超音波の固有振動を用いることで粘性減衰の影響を受けない損傷評価法を実現する.

Outline of Final Research Achievements

In this study, I developed the multi-excitation method using decentralized control with local feedback control for excitation of ultrasonic natural vibrations and the detection method of contact-type failure based on nonlinear wave modulation using developed multi-excitation method. Firstly, the multi-excitation method was developed. The analog circuit of local feedback control was designed. Therefore, it was confirmed that the ultrasonic natural vibration can be excited. Moreover, the change of natural vibration modes was realized by forced entrainment. Next, the detection experiment of contact-type failure based on nonlinear wave modulation using sexcited ultrasonic natural vibrations. It was confirmed that the oscillated frequency of ultrasonic vibrations is varied in synchronization with varying of the natural frequencies caused by nonlinear wave modulation. Therefore, the variation width of oscillated frequencies increases with the development of contact-type failure.

Academic Significance and Societal Importance of the Research Achievements

大型構造物に生じる疲労き裂やボルト緩みなどは,損傷面が接触しており検出が困難である場合がある.このような接触型損傷を精度よく検出することは,構造物の劣化度合いを正確に評価するために重要である.微小な接触型損傷を精度よく検出する手法の一つに,超音波振動の振幅や位相に生じる変調(非線形波動変調)に基づく手法があるが,大型構造物では超音波固有振動の励起が困難であるため適用できなかった.本研究では,超音波固有振動で自動的に発振し,固有振動モードに合わせて加振力が自動的に調整される分散制御型多点加振を実現し,非線形波動変調に基づく接触型損傷検出法の大型構造物への適用を可能にした.

Report

(3 results)
  • 2021 Annual Research Report   Final Research Report ( PDF )
  • 2020 Research-status Report
  • Research Products

    (3 results)

All 2021 2020

All Presentation (3 results) (of which Int'l Joint Research: 1 results)

  • [Presentation] Excitation of ultrasonic natural vibrations by multi-Excitation using decentralized control for failure monitoring2021

    • Author(s)
      Takashi Tanaka, Takato Tamura, Yasunori Oura
    • Organizer
      ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 非線形波動変調に基づく接触型損傷の検出(伝達関数の時間変動計測による損傷評価)2021

    • Author(s)
      田村空翔,田中昂,大浦 靖典,今村紘大
    • Organizer
      Dynamics & Design Conference 2021
    • Related Report
      2021 Annual Research Report
  • [Presentation] 自励発振と同期現象により励起した超音波帯域の固有振動計測による損傷評価に関する基礎研究2020

    • Author(s)
      田中昂,田村空翔,大浦靖典
    • Organizer
      第28回超音波による非破壊評価シンポジウム
    • Related Report
      2020 Research-status Report

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Published: 2020-04-28   Modified: 2023-01-30  

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