Time-Frequency Blind Source Separation Using Independent Component Analysis for Output-Only Modal Identification of Highly Damped Structures
Publication: Journal of Structural Engineering
Volume 139, Issue 10
Abstract
Output-only algorithms are needed for modal identification when only structural responses are available. The recent years have witnessed the fast development of blind source separation (BSS) as a promising signal processing technique, pursuing to recover the sources using only the measured mixtures. As the most popular tool solving the BSS problem, independent component analysis (ICA) is able to directly extract the time-domain modal responses, which are viewed as virtual sources, from the observed system responses; however, it has been shown that ICA loses accuracy in the presence of higher-level damping. In this study, the modal identification issue, which is incorporated into the BSS formulation, is transformed into a time-frequency framework. The sparse time-frequency representations of the monotone modal responses are proposed as the targeted independent sources hidden in those of the system responses which have been short-time Fourier-transformed (STFT); they can then be efficiently extracted by ICA, whereby the time-domain modal responses are recovered such that the modal parameters are readily obtained. The simulation results of a multidegree-of-freedom system illustrate that the proposed output-only STFT-ICA method is capable of accurately identifying modal information of lightly and highly damped structures, even in the presence of heavy noise and nonstationary excitation. The laboratory experiment on a highly damped three-story frame and the analysis of the real measured seismic responses of the University of Southern California hospital building demonstrate the capability of the method to perform blind modal identification in practical applications.
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Acknowledgments
The authors thank the researchers at Helsinki University of Technology for sharing the FastICA software package (available at http://www.cis.hut.fi/projects/ica/fastica/). Partial funding for this study provided by Fugro International is gratefully acknowledged. The authors also acknowledge useful discussions with Dr. Sriram Narasimhan of University of Waterloo.
References
Antoni, J. (2005). “Blind separation of vibration components: Principles and demonstrations.” Mech. Syst. Signal Process., 19(6), 1166–1180.
Basu, B., Nagarajaiah, S., and Chakraborty, A. (2008). “Online identification of linear time-varying stiffness of structural systems by wavelet analysis.” Struct. Health Monit., Proc. Eur. Workshop, 7(1), 21–36.
Bell, A. J., and Sejnowski, T. J. (1995). “An information maximization approach to blind separation and blind deconvolution.” Neural Comput., 7(6), 1129–1159.
Belouchrani, A., Abed-Meraim, A. K., Cardoso, J.-F., and Moulines, E. (1997). “A blind source separation technique using second-order statistics.” IEEE Trans. Acoust., Speech, Signal Process., 45(2), 434–444.
Brincker, R., Zhang, L., and Andersen, P. (2001). “Modal identification of output-only systems using frequency domain decomposition.” Smart Mater. Struct., 10(3), 441–445.
Comon, P., and Rajih, M. (2006). “Blind identification of under-determined mixtures based on the characteristic function.” Signal Process., 86(9), 2271–2281.
Doebling, S. W., Farrar, C. R., Prime, M. B., and Shevitz, D. W. (1996). “Damage identification and health monitoring of structural and mechanical systems from changes in their vibration characteristics: A literature review.” Rep. LA-13070-MS, UC-900, Los Alamos National Laboratory, Los Alamos, NM.
FastICA [Computer software]. Helsinki, Finland, Helsinki Univ. of Technology.
Friswell, M. I., and Mottershead, J. E. (1995). Finite element model updating in structural dynamics, Kluwer Academic Publishers, London.
Hazra, B., and Narasimhan, S. (2010). “Wavelet-based blind identification of the UCLA Factor building using ambient and earthquake responses.” Smart Mater. Struct., 19(2), 025005.
Hazra, B., Roffel, A. J., Narasimhan, S., and Pandey, M. D. (2010). “Modified cross-correlation method for the blind identification of structures.” J. Eng. Mech., 136(7), 889–897.
Hyvärinen, A., and Oja, E. (2000). “Independent component analysis: Algorithms and applications.” Neural Netw., 13(4–5), 411–430.
Hyvärinen, A., Ramkumar, P., Parkkonen, L., and Hari, R. (2010). “Independent component analysis of short-time Fourier transforms for spontaneous EEG/MEG analysis.” Neuroimage, 49(1), 257–271.
Ibrahim, S. R., and Mikulcik, E. C. (1973). “A time domain modal vibration test technique.” Shock and vibration bulletin, Vol. 43, Naval Research Laboratory, Washington, DC, 21–37.
James, G. H., Carne, T. G., and Lauffer, J. P. (1995). “The natural excitation technique (NExT) for modal parameter extraction from operating structures.” Int. J. Analytic. Exp. Modal Analysis, 10(4), 260–277.
Juang, J. N., and Pappa, R. S. (1985). “An eigen system realization algorithm for modal parameter identification and model reduction.” J. Guid. Control Dyn., 8(5), 620–627.
Kerschen, G., Poncelet, F., and Golinval, J.-C. (2007). “Physical interpretation of independent component analysis in structural dynamics.” Mech. Syst. Signal Process., 21(4), 1561–1575.
Madhow, U. (1998). “Blind adaptive interference suppression for direct-sequence CDMA.” Proc. IEEE, 86(10), 2049–2069.
McNeill, S. (2007). “Modal identification using blind source separation techniques.” Ph.D. dissertation, Dept. of Mechanical Engineering, Univ. of Houston, Houston.
McNeill, S. I., and Zimmerman, D. C. (2008). “A framework for blind identification using joint approximate diagonalization.” Mech. Syst. Signal Process., 22(7), 1526–1548.
Nagarajaiah, S. (2009). “Adaptive passive, semiactive, smart tuned mass damper: Identification and control using empirical mode decomposition, Hilbert transform, and short-time Fourier transform.” Struct. Contr. Health Monit., 16(7–8), 800–841.
Nagarajaiah, S., and Basu, B. (2009). “Output only identification and structural damage detection using time frequency and wavelet techniques.” Earthquake Eng. Eng. Vib., 8(4), 583–605.
Nagarajaiah, S., and Dharap, P. (2003). “Reduced order observer based identification of base isolated buildings.” Earthquake Eng. Eng. Vib., 2(2), 237–244.
Nagarajaiah, S., and Li, Z. (2004). “Time segmented least squares identification of base isolated buildings.” Soil. Dyn. Earthquake Eng., 24(8), 577–586.
Nagarajaiah, S., and Sun, X. (2000). “Response of base-isolated USC hospital building in Northridge earthquake.” J. Struct. Eng., 126(10), 1177–1186.
Poncelet, F., Kerschen, G., Golinval, J.-C., and Verhelst, D. (2007). “Output-only modal analysis using blind source separation techniques.” Mech. Syst. Signal Process., 21(6), 2335–2358.
Spencer, B. F., and Nagarajaiah, S. (2003). “State of the art of structural control.” J. Struct. Eng., 129(7), 845–856.
VanOverschee, P., and De Moor, B. (1996). Subspace identification for linear systems: Theory, implementation, application, Kluwer Academic Publisher, Dordrecht, Netherlands.
Zhou, W., and Chelidze, D. (2007). “Blind source separation based vibration mode identification.” Mech. Syst. Signal Process., 21(8), 3072–3087.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 139 • Issue 10 • October 2013
Pages: 1780 - 1793
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Sep 2, 2011
Accepted: Mar 30, 2012
Published online: Apr 11, 2012
Published in print: Oct 1, 2013
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