Real-time Failure Detection of Composite Structures Using Optical Fiber Sensors

광섬유 센서를 이용한 복합재 구조물의 실시간 파손감지

  • 방형준 (한국과학기술원 기계공학과 항공우주공학전공) ;
  • 강현규 (한국과학기술원 기계공학과 항공우주공학전공) ;
  • 류치영 (한국과학기술원 기계공학과 항공우주공학전공) ;
  • 김대현 (한국과학기술원 기계공학과 항공우주공학전공) ;
  • 강동훈 (한국과학기술원 기계공학과 항공우주공학전공) ;
  • 홍창선 (한국과학기술원 기계공학과 항공우주공학전공) ;
  • 김천곤 (한국과학기술원 기계공학과 항공우주공학전공)
  • Published : 2000.11.01

Abstract

The objective of this research is to develop real-time failure detection techniques for damage assessment of composite materials using optical fiber sensors. Signals from matrix cracking or fiber fracture in composite laminates are treated by signal processing unit in real-time. This paper describes the implementation of time-frequency analysis such as the Short Time Fourier Transform(STFT) to determine the time of occurrence of failure. In order to verify the performance of the optical fiber sensor for stress wave detection, we performed pencil break test with EFPI sensor and compared it with that of PZT. The EFPI sensor was embedded in composite beam to sense the failure signals and a tensile test was performed. The signals of the fiber optic sensor when damage occurred were characterized using STFT and wavelet transform. Failure detection system detected the moment of failure accurately and showed good sensitivity with the infinitesimal failure signal.