Development of a Thickness Mode Piezoelectric Oscillator Sensor to Detect Damages in a Structure

구조물 손상 탐지를 위한 두께 방향 모드 압전 오실레이터 센서 개발

  • Published : 2007.02.28

Abstract

This paper presents the feasibilityof a thickness mode piezoelectric oscillator to detect damages in structures. The thickness mode oscillator sensor is composed of an electronic feedback oscillator circuit and a piezoelectric thickness mode vibrator to be attached to a structure of interest. Damage to the structure causes a change in the impedance spectrum of the structure, which results in a corresponding change of a resonant frequency of the structure. The oscillator sensor can instantly detect the frequency change in a very simple manner. Feasibility of the piezoelectric oscillator sensor was verified with a sample aluminum plate where artificial cracks of different lengths and number were imposed in sequence. Validity of the measurement was confirmed through comparison of the experimental data with the results of finite element analyses of a plate with cracks.

본 논문에서는 구조물의 손상탐지를 위한 두께 방향 모드 압전 오실레이터의 가능성을 연구하였다. 두께 방향 모드 오실레이터 센서는 구조물의 주요부에 부착된 두께 방향 모드 압전소자와 피드백 오실레이터 회로로 구성되어있다. 구조물의 손상은 구조물의 임피던스를 변화를 야기시키며, 그 결과로 구조물의 공진 주파수가 변하게 된다. 오실레이터 센서는 간단한 방법으로 이 공진 주파수 변화를 연속적으로 관측할 수 있다. 본 연구에서는 알루미늄 시편에 크랙의 크기와 개수를 인위적으로 변화시키면서, FEM해석과 실험을 통해 두께 방향 모드 압전 오실레이터 센서의 적용 가능성을 증명 하였다.

Keywords

References

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