한국정밀공학회:학술대회논문집 (Proceedings of the Korean Society of Precision Engineering Conference)
- 한국정밀공학회 2001년도 춘계학술대회 논문집
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- Pages.135-139
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- 2001
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- 2005-8446(pISSN)
광섬유 브래그 격자 변형률 센서용 현공진기의 고정밀 측정
High Precision Measurement for String Resonator used in FBG Strain Sensors
초록
This paper describes a string resonator that is used for the interrogation system of a Fiber Bragg Grating(FBG) strain sensor. The strain on the fiber piece is calculated from the measured frequency based on that the natural frequency of a string is a function of the applied absolute strain. Existing research considered a fiber as a string, but a fiber is not a string in the strict sense due to its bending stiffness, thus the fiber should be modeled as a beam accompanied with an axial force. In the vibration modeling, the relationship between the strain and the natural frequency is derived, and then the resonance condition is described in terms of both the phase and the mode shape for sustaining resonant motion. Several experiments verify the effectiveness of the proposed model of the fiber. The performance of the string resonator is analyzed by measuring the frequency change according to the applied strains in the dynamic range of 1100
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