Abstract
A recent development in operational modal analysis (OMA) is the possibility of using measured, artificial loads in addition to the unmeasured, ambient excitation, while the ratio between forced and ambient excitation can be low compared to classical experimental modal analysis (EMA). Most of these so-called OMAX algorithms lack the intuitiveness of their EMA and OMA counterparts, since they fit a system model that takes both the measured and the operational excitation into account directly to the measured signals. A more physically intuitive subspace algorithm for OMAX, that starts with an accurate decomposition of the measured joint response in a forced and an ambient part, was recently introduced. In this paper, the performance of this algorithm, which is called CSI-ic/ref, is assessed by means of a case study, where a two-span steel arch footbridge is tested in operational conditions, with and without using additional actuators. From a comparison of the modal parameters with results from a finite elementmodel, an OMA algorithm, and an alternative OMAX algorithm, it can be concluded that CSI-ic/ref yields accurate modal parameter estimates.
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References
E. Caetano, ´A. Cunha, and C. Moutinho. Implementation of passive devices for vibration control at Coimbra footbridge. In Proceedings of the converence on experimental vibration analysis for civil engineering structures - EVACES07, pages 43–54, Porto, Portugal, October 2007.
B. Cauberghe. Applied frequency-domain system identification in the field of experimental and operational modal analysis. PhD thesis, Vrije Universiteit Brussel, 2004.
B. Cauberghe, P. Guillaume, P. Verboven, and E. Parloo. Identification of modal parameters including unmeasured forces and transient effects. Journal of Sound and Vibration, 265(3):609–625, 2003.
P. Dallard, A.J. Fitzpatrick, A. Flint, S. Le Bourva, A. Low, R.M. Ridsdill Smith, and M. Willford. The London Millennium Footbridge. The Structural Engineer, 79(22):17–33, 2001.
K. Deckers, P. Guillaume, D. Lefeber, G. De Roeck, and E. Reynders. Modal testing of bridges using low-weight pneumatic artificial muscle actuators. In Proceedings of IMAC 26, the International Modal Analysis Conference, Orlando, FL, February 2008. CD-ROM.
P. Guillaume, T. De Troyer, C. Devriendt, and G. De Sitter. OMAX - a combined experimental-operational modal analysis approach. In P. Sas and M. De Munck, editors, Proceedings of ISMA2006 International Conference on Noise and Vibration Engineering, pages 2985–2996, Leuven, Belgium, September 2006.
W. Heylen, S. Lammens, and P. Sas. Modal analysis theory and testing. Department of Mechanical Engineering, Katholieke Universiteit Leuven, Leuven, Belgium, 1997.
S.Y. Kung. A new identification and model reduction algorithm via singular value decomposition. In Proceedings of the 12th Asilomar conference on circuits, systems and computers, pages 705–714, Pacific Grove, CA, 1978.
E. Parloo, P. Verboven, P. Guillaume, and M. Van Overmeire. Sensitivity-based operational mode shape normalization. Mechanical Systems and Signal Processing, 16(5):757–767, 2002.
B. Peeters and G. De Roeck. Reference-based stochastic subspace identification for output-only modal analysis. Mechanical Systems and Signal Processing, 13(6):855–878, 1999.
B. Peeters and G. De Roeck. Stochastic system identification for operational modal analysis: A review. ASME Journal of Dynamic Systems, Measurement, and Control, 123(4):659–667, 2001.
R. Pintelon and J. Schoukens. System Identification. IEEE Press, New York, NY, 2001.
E. Reynders. System identification and modal analysis in structural mechanics. PhD thesis, Department of Civil Engineering, K.U.Leuven, 2009.
E. Reynders and G. De Roeck. Reference-based combined deterministic-stochastic subspace identification for experimental and operational modal analysis. Mechanical Systems and Signal Processing, 22(3):617–637, 2008.
E. Reynders and G. De Roeck. On the separation of a measured structural response in a forced and an ambient part for OMAX testing. In Proceedings of ISMA2010 International Conference on Noise and Vibration Engineering, pages 3287–3302, Leuven, Belgium, September 2010.
E. Reynders, D. Degrauwe, G. De Roeck, F.Magalh˜aes, and E. Caetano. Combined experimental-operational modal testing of footbridges. ASCE Journal of Engineering Mechanics, 136(6):687–696, 2010.
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Reynders, E. et al. (2011). OMAX testing of a steel bowstring footbridge. In: Proulx, T. (eds) Civil Engineering Topics, Volume 4. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-9316-8_15
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DOI: https://doi.org/10.1007/978-1-4419-9316-8_15
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