DOI QR코드

DOI QR Code

Determining the Size of a Hankel Matrix in Subspace System Identification for Estimating the Stiffness Matrix and Flexural Rigidities of a Shear Building

전단빌딩의 강성행렬 및 부재의 강성추정을 위한 부분공간 시스템 확인기법에서의 행켈행렬의 크기 결정

  • Park, Seung-Keun (Research Institute of Construction Technology and Planning, Dong-A Univ.) ;
  • Park, Hyun Woo (Department of Civil Engineering, Dong-A Univ.)
  • 박승근 (동아대학교 건설기술연구소) ;
  • 박현우 (동아대학교 토목공학과)
  • Received : 2012.11.27
  • Accepted : 2013.01.22
  • Published : 2013.04.30

Abstract

This paper presents a subspace system identification for estimating the stiffness matrix and flexural rigidities of a shear building. System matrices are estimated by LQ decomposition and singular value decomposition from an input-output Hankel matrix. The estimated system matrices are converted into a real coordinate through similarity transformation, and the stiffness matrix is estimated from the system matrices. The accuracy and the stability of an estimated stiffness matrix depend on the size of the associated Hankel matrix. The estimation error curve of the stiffness matrix is obtained with respect to the size of a Hankel matrix using a prior finite element model of a shear building. The sizes of the Hankel matrix, which are consistent with a target accuracy level, are chosen through this curve. Among these candidate sizes of the Hankel matrix, more proper one can be determined considering the computational cost of subspace identification. The stiffness matrix and flexural rigidities are estimated using the Hankel matrix with the candidate sizes. The validity of the proposed method is demonstrated through the numerical example of a five-story shear building model with and without damage.

이 논문은 부분공간 시스템 확인기법을 이용하여 전단빌딩의 강성행렬과 부재의 강성을 추정하는 기법을 소개한다. 시스템 행렬은 입력-출력 데이터로 구성된 행켈행렬을 LQ 분해와 특이치 분해를 통해 추정한다. 추정된 시스템 행렬은 닮음 변환을 통해 실제 좌표축으로 변환하고, 변환된 시스템 행렬로부터 강성행렬을 계산한다. 추정된 강성행렬의 정확성과 안정성은 행켈행렬의 크기에 따라 변한다. 전단빌딩의 기저 유한요소 모델을 이용하여 행켈행렬의 크기에 따른 강성행렬의 추정 오차 곡선을 구한다. 오차 곡선을 이용하여 목표 정확도 수준에 부합하는 행켈행렬의 크기들을 결정한다. 이렇게 선택된 행렬의 크기들 중에서 부분공간 시스템 확인의 계산비용을 고려하여 보다 적절한 행렬의 크기를 결정할 수 있다. 결정된 크기의 행켈행렬을 이용하여 강성행렬을 추정하고 추정된 강성행렬로부터 부재의 강성을 추정한다. 제안된 방법을 손상 전후의 5층 전단빌딩 수치 예제에 적용하여 타당성을 검증한다.

Keywords

References

  1. Alvin, K.F., Park, K.C. (1994) Second-Order Structural Identification Procedure Via State-Space-Based System Identification, AIAA Journal, 32(2), pp.397-406. https://doi.org/10.2514/3.11997
  2. Banan, M.R., Hjelmstad, K.D. (1993) Identification of Structural System from Measured Response, Structural Research Series, 579, UILU-ENG-93-2002, University of Illinois, Urbana, Illinois.
  3. Banan, M.R., Banan, M.R., Hjelmstad, K.D. (1995) Time-domain Parameter Estimation Algorithm for Structures II: Numerical Simulation Studies, Journal of Engineering Mechanics, 121(3), pp.435-447. https://doi.org/10.1061/(ASCE)0733-9399(1995)121:3(435)
  4. Hjelmstad, K.D., Banan, M.R., Banan, M.R. (1995) Time-domain Parameter Estimation Algorithm for Structures I: Computational Aspects, Journal of Engineering Mechanics, 121(3), pp.424-434. https://doi.org/10.1061/(ASCE)0733-9399(1995)121:3(424)
  5. Hjelmstad, K.D., Shin, S. (1996) Crack Identification in a Cantilever Beam from Modal Response, Journal of Sound and Vibration 198(5), pp.527-545. https://doi.org/10.1006/jsvi.1996.0587
  6. Hoshiya, M., Saito, E. (1984) Structural Identification by Extended Kalman Filter, Journal of Engineering Mechanics, 110, pp.1757-1770. https://doi.org/10.1061/(ASCE)0733-9399(1984)110:12(1757)
  7. Kang, J.S., Park, S.-K., Shin, S., Lee, H.S. (2005) Structural System Identification in time Domain using Measured Acceleration, Journal of Sound and Vibration, 288(1-2), pp.215-234. https://doi.org/10.1016/j.jsv.2005.01.041
  8. Katayama, T. (2005) Subspace Methods for System Identification, Springer-Verlag London Limited, p. 387.
  9. Koh, B.H., Nagarajaiah, S., Phan, M.Q. (2008) Reconstructing Structural Changes in a Dynamic System from Experimentally Identified State-Space Models, Journal of Mechanical Science and Technology, 22, pp.103-112. https://doi.org/10.1007/s12206-007-1012-y
  10. Min, K.-W., Joo, S.-J., Lee, S.-H. (2004) Observer Kalman Filter Identification of a Three-Story Structure Installed with Active Mass Driver, Journal of Computational Structural Engineering, 17(2), pp.161-169.
  11. Overschee, P. Van., Moor, B. De. (1996) Subspace Identification for Linear Systems, Kluwer Academic Publishers, Massachusetts, USA, p.248.
  12. Park, S.-K., Park, H.W., Shin, S., Lee, H.S. (2008) Detection of Abrupt Structural Damage Induced by an Earthquake using a Moving Time-window Technique, Computers and Structures, 86(11-12), pp.1253-1265. https://doi.org/10.1016/j.compstruc.2007.11.003
  13. Phan, M.Q., Longman, R.W. (2004) Extracting Mass, Stiffness and Damping Matrices from Identified State-Space Models, AIAA Guidance, Navigation and Control Conference and Exhibit, Rhode Island, August 16-19.
  14. Raghavendrachar, M., Aktan, A.E. (1992) Flexibility by Multireference Impact Testing for Bridge Diagnostics, Journal of Structural Engineering 118(8), pp.2186-2203. https://doi.org/10.1061/(ASCE)0733-9445(1992)118:8(2186)
  15. Shi, Z.Y., Law S.S., Zhang, L.M. (2000) Damage Localization by Directly using Incomplete Mode Shapes, Journal of Engineering Mechanics, 126(6), pp.656-660. https://doi.org/10.1061/(ASCE)0733-9399(2000)126:6(656)
  16. Verhaegen, M., Dewilde, P. (1992) Subspace Model Identification Part 2. Analysis of the Elementary Output-Error State-Space Model Identification Algorithm, International Journal of Control, 56(5), pp.1211-1241. https://doi.org/10.1080/00207179208934364
  17. Vestroni, F., Capecchi, D. (2000) Damage Detection in Beam Structures Based on Frequency Measurements, Journal of Engineering Mechanics, 126(7), pp.761-768. https://doi.org/10.1061/(ASCE)0733-9399(2000)126:7(761)
  18. Viberg, M. (1995) Subspace-Based Methods for the Identification of Linear Time-Invariant Systems, Automatica, 31(12), pp.1835-1851. https://doi.org/10.1016/0005-1098(95)00107-5
  19. Yun, C-.B., Shinozuka, M. (1980) Identification of Nonlinear Structural Dynamic Systems, Journal of Structural Mechanics, 8(2), pp.187-203. https://doi.org/10.1080/03601218008907359