Structural Engineering and Mechanics

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Identification of prestress force in a prestressed Timoshenko beam

  • Lu, Z.R. (School of Engineering, Sun Yat-sen University) ;
  • Liu, J.K. (School of Engineering, Sun Yat-sen University) ;
  • Law, S.S. (Civil and Structural Engineering Department, The Hong Kong Polytechnic University)
  • Received : 2006.12.15
  • Accepted : 2008.03.24
  • Published : 2008.06.20
⟨ Previous Next ⟩

Abstract

This paper presents a new identification approach to prestress force. Firstly, a bridge deck is modeled as a prestressed Timoshenko beam. The time domain responses of the beam under sinusoidal excitation are studied based on modal superposition. The prestress force is then identified in the time domain by a system identification approach incorporating with the regularization of the solution. The orthogonal polynomial function is used to improve the noise effect and obtain the derivatives of modal responses of the bridge. Good identification results are obtained from only the first few measured modal data under both sinusoidal and impulsive excitations. It is shown that the proposed method is insensitive to the magnitude of force to be identified and can be successfully applied to indirectly identify the prestress force as well as other physical parameters, such as the flexural rigidity and shearing rigidity of a beam even under noisy environment.

Keywords

References

  1. Abraham, M.A., Park, S.Y. and Stubbs, N. (1995), "Loss of prestress prediction on nondestructive damage location algorithms", SPIE, Smart Struct. Mater., 244, 60-67
  2. Abramovich, H. (1991), "Natural frequencies of Timoshenko beams under compressive axial loads", J. Sound Vib., 157(1), 183-189
  3. Kim, J.T., Yun, C.B., Ryu, Y.S. and Cho, H.M. (2004), "Identification of prestress-loss in PSC beams using modal information", Struct. Engi. Mech., 17(3-4), 467-482 https://doi.org/10.12989/sem.2004.17.3_4.467
  4. Law, S.S. and Lu, Z.R. (2005), "Time domain responses of a prestressed beam and prestress force identification", J. Sound Vib., 288, 1011-1025 https://doi.org/10.1016/j.jsv.2005.01.045
  5. Law, S.S. and Zhu, X.Q. (2000), "Study on different beam models in moving force identification", J. Sound Vib., 234, 661-679 https://doi.org/10.1006/jsvi.2000.2867
  6. Miyamoto, A., Tei, K., Nakamura, H. and Bull, J.W. (2000), "Behavior of prestressed beam strengthened with external tendons", J. Struct. Eng., ASCE, 126(9), 1033-1044 https://doi.org/10.1061/(ASCE)0733-9445(2000)126:9(1033)
  7. Newmark, N.W. (1959), "A method of computation for structural dynamics", J. Eng. Mech. Div., ASCE, 85(3), 67-94
  8. Saiidi, N., Douglas, B. and Feng, S. (1994), "Prestress force effect on vibration frequency of concrete bridges", J. Struct. Eng., ASCE, 120(7), 2233-2241 https://doi.org/10.1061/(ASCE)0733-9445(1994)120:7(2233)

Cited by

  1. Numerical comparison of the beam model and 2D linearized elasticity vol.33, pp.5, 2009, https://doi.org/10.12989/sem.2009.33.5.621
  2. Effective Pre-Stress Identification for a Simply-Supported PRC Bridge Based on the Dynamic Response Induced by the Passing Vehicle vol.430-432, pp.1662-8985, 2012, https://doi.org/10.4028/www.scientific.net/AMR.430-432.1320