Monitoring System For The Subway Structures Using Prestrained FBG Sensors Fixed With Partially Stripped Fibers

부분탈피 고정방식 프리스트레인 가변형 광섬유격자센서를 이용한 지하철 구조물 변위 모니터링시스템

  • 김기수 (홍익대학교 재료공학부)
  • Published : 2008.12.30

Abstract

A monitoring system for the subway structures using prestrained FBG sensors fixed with partially stripped fibers was developed. The sensor packages had pre-strain controllable fixtures. Tensile and compressive strain of the structure could be measured without slip. The FBG sensor system was applied to the concrete lining structure in Taegu subway. Near the structure, the narrow tunnel construction, for the electric power cables and telecommunication cables, started. We wanted to measure the deformations of the subway structures due to the construction by the FBG sensor. The applied sensors had the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

References

  1. Kim, K. S., Kollar, L., Springer, G. S. (1993) A Model of Embedded Fiber Optic Fabry-Perot Temperature and Strain Sensors, J. of Composite Materials, 27, pp.1618-1662 https://doi.org/10.1177/002199839302701701
  2. Koo, K. P., Kersey, A. D. (1995) Bragg Grating-Based Laser Sensors Systems with Interferometric Interrogation and Wavelength Division Multiplexing, Journal of Lightwave Technology, 13(7), pp.1243-1248 https://doi.org/10.1109/50.400692
  3. Measures, R. M. (1991) Fiber optic sensor considerations and developments for smart structures, Proc. SPIE, 1588, p.282
  4. Melle, M., Kexing Liu, Raymond M. (1992) A Passive Wavelength Demodulation System for Guided-Wave Bragg Grating Sensors, IEEE PHOTONICS TECHNOLOGY LETTERS, 4(5), pp.516-518 https://doi.org/10.1109/68.136506
  5. 김기수 (2003) System Identification에 활용할 수 있는 광섬유 센서 계측 시스템, 전산구조공학, 16(1) pp.39-43
  6. Meltz, G., Morey, W. W., Glenn, W. H. (1989) Formation of Bragg grating in optical fibers by a transverse holographic method, Optics Letters, 14, pp.823-825 https://doi.org/10.1364/OL.14.000823
  7. Stone, J., Stulz, L. W. (1987) Pigtailed high-finesse tunable fiber Fabry-Perot Interferometer with large, medium and small free spectral range, Elect. Lett., 23(15), pp.781-783 https://doi.org/10.1049/el:19870554
  8. Hill, K. O., Fujii, Y.. Johnson, D. C., Kawasaki, B. S. (1978) Photosensitivity in Optical Fiber Waveguides. Application to Reflection Filter Fabrication, Appl. Phys. Lett., 32(10), pp.647-649 https://doi.org/10.1063/1.89881
  9. Kersey, A. D., Koo, K. P., Davis, M. A. (1994) Fiber Optic Bragg Grating Laser Sensors, SPIE, 2292, pp.102-112
  10. Morey, W. W., Dunphy, J. R., Meltz, G. (1994) Multiplexing Fiber Bragg Grating Sensor, SPIE, Vol. 1586, Paper #22, Boston, pp.216-224
  11. Morey, W. W., Meltz, G., Glenn, W. H. (1989) Fiber Optic Bragg Grating Sensors, SPIE, 1169, pp.98-106
  12. Kersey, A. D., Berkoff, T. A., Morey, W. W. (1992) High-Resolution Fiber-Grating Based Strain Sensor with Interferometric Wavelength-Shift Detection, ELECTRONICS LETTERS, 30th, 28(3), pp.516-518
  13. Kim, K. S., Breslauer, M., Springer, G. S. (1992) The Effect of Embedded Sensor on the Strength of Composite Laminates, J. of Reinforced Plast and Comp, 2, pp.949-958