Extracting Modal Parameters of Railway Bridge under the Action of High-speed Train Using TDD Technique

TDD기법을 이용한 고속철도 교량의 동특성 추출

  • 김병화 (경남대학교 토목공학과)
  • Received : 2008.07.30
  • Accepted : 2008.09.08
  • Published : 2008.12.10

Abstract

When the crossing frequency of a train meets the natural frequency of a railway bridge, the bridge is bound to become resonant. There are few available time response samples involving a train that passes a bridge at high speed. Very effective modal-parameter extraction techniques for such special high-speed railway bridge conditions are introduced in this paper. Utilizing the cross-correlations of the free-vibration responses after the train passes, mode shapes and the temporal modal parameters (e.g., natural frequency and damping ratio) are extracted using the TDD and SI techniques, respectively. This approach has been applied to a two-span steel composite bridge in the Kyung-Bu high-speed railway system. The estimation results were compared with those obtained using the existing methods. The results fully coincide with those that were extracted using the existing aforementioned technique.

열차운행주파수가 철도교의 고유진동수와 일치하면, 철도교의 공진은 피할 수 없다. 또한, 열차가 교량을 매우 빠르게 통과하면, 계측 가능한 시간응답의 샘플 수는 매우 적다. 본 논문은 그러한 경우에 대하여 철도 교량의 동특성을 매우 효과적으로 추출할 수 있는 TDD기법과 SI기법을 소개한다. 열차통과 직후에 교량의 자유진동 시간응답구간의 상호상관을 이용하여 모드형상은 TDD기법으로 추출하고, 고유진동수 및 감쇠비 등의 시간변수들은 SI기법으로 추출한다. 경부고속철도 시스템에 위치한 2경간 강합성교량의 동특성 추출실험을 통하여 TDD기법과 SI기법의 현장 적용성이 검토되었다. 동특성 추정결과는 기존의 ERADC기법의 결과와 비교 검토되었다. 추정결과는 기존의 방법을 이용하여 획득된 결과와 매우 잘 일치한다.

Keywords

References

  1. 곽종원, 진원종, 김영진, 김병석 (2003) 경부고속철도 주행에 의한 콘크리트 상자형 교량의 동적거동, 대한토목학회논문집, 제23권, 제 1A호, pp. 27-36
  2. 이정휘, 김성일, 곽종원, 이필구, 윤태양 (2007) 고속철도 강교량의 진통특성 분성, 한국소음진동공학회논문집, Vol. 17, No.7, pp. 632-637 https://doi.org/10.5050/KSNVN.2007.17.7.632
  3. Bendat, J. S., and Piersol, A. G. (1980). Engineering Applications of Correlation and Spectral Analysis. Wiley, New York, pp. 181-186
  4. Brinker, R. Zhang, L., and Anderson, P. (2001) Modal identification of output-only systems using frequency domain decomposition, Smart Materials and Structures, Vol.10, pp. 441-445 https://doi.org/10.1088/0964-1726/10/3/303
  5. Cremona, C. (2004) Dynamic monitoring applied to the detection of structural modifications: a high-speed railway bridge study, Prog. Struct. Engng Mater., Vol. 6, pp.147-161 https://doi.org/10.1002/pse.177
  6. Farrar, C .R. and James III, G. H. (1997) System Identification from Ambient Vibration Measurements on Bridge, Journal of Sound and Vibration, Vol. 205, pp.1-18 https://doi.org/10.1006/jsvi.1997.0977
  7. Ibrahim, S. R. and Mikulick, E. C. (1977) A Method for the Identification of Vibration Parameters from the Free Responses, Shock and Vibration Bulletin, Vol. 47, No. 4, pp.183-198
  8. James III, G. H., Carne, T. G., Lauffer, J. P. (1993) The natural excitation technique (NExt) for modal parameter extraction from operating wind turbines., Sandia National Laboratory, Report SAND92-1666
  9. Ju, S. H. and Lin H. T. (2003) Resonance characteristics of high-speed trains passing simply supported bridges, Journal of Sound and Vibration, Vol. 267, pp.1127-1141 https://doi.org/10.1016/S0022-460X(02)01463-3
  10. Juang, J. -N. (1994), Applied System Identification, Prentice-Hall, Englewood Cliffs, NJ
  11. Kim, B. H., Park, T., and Stubbs, N. (2005) A New Method to Extract Modal Parameters Using Output-Only Responses, Journal of Sound and Vibration, Vol. 282, pp. 215-230 https://doi.org/10.1016/j.jsv.2004.02.026
  12. Kim, B. H. Park, T., and Voyiadjis, G. Z. (2006) Damage Estimation on Beam-like Structures Using the Multi-resolution Analysis, International Journal of Solids and Structures, Vol. 43, pp. 4238-4257 https://doi.org/10.1016/j.ijsolstr.2005.07.022
  13. Kwark, J. W., Choi, E. S., Y. J. Kim, Kim, B. S. and Kim, S. I. (2004) Dynamic behavior of two-span continuous concrete bridges under moving high-speed train, Computers and Structures, Vol.82, pp. 463-474 https://doi.org/10.1016/S0045-7949(03)00054-3
  14. Peeters, B. and De Roeck, G. (2000) Reference based stochastic subspace identification in civil engineering, Inverse Problems in Engineering, Vol. 8, No. 1, pp. 47-74 https://doi.org/10.1080/174159700088027718
  15. Rebelo, C., Silva, S. D., Rigueiro, C., and Pircher, M. (2008) Dynamic behaviour of twin single-span ballasted railway viaducts-Field measurements and modal identification, Engineering Structures, doi:10.1016/j.engstruct
  16. Stubbs, N. and Kim, J. T. (1996) Damage localization in structures without baseline modal parameters, American Institute of Aeronautics and Astronautics Journal, Vol. 34, pp. 1644-1649 https://doi.org/10.2514/3.13284
  17. Xia, H., Zhang, N., and Gao, R. (2005) Experimental analysis of railway bridge under high-speed trains, Journal of Sound and Vibration, Vol. 282, pp. 517-528 https://doi.org/10.1016/j.jsv.2004.04.033
  18. Yang, Y. -B., Yau, J. -D., Hsu, L. -C. (1997) Vibration of simple beams due to trains moving at high speeds, Engineering Structures, Vol.19, No. 11, pp. 936-944 https://doi.org/10.1016/S0141-0296(97)00001-1