Identification of the Mechanical Subsystem of the NEES-UCSD Shake Table by a Least-Squares Approach
Publication: Journal of Engineering Mechanics
Volume 134, Issue 1
Abstract
A least-squares method is used to determine the fundamental parameters of a simple mathematical model for the mechanical subsystem of the NEES-UCSD large high performance outdoor shaking table. The parameters identified include the effective horizontal mass, the effective horizontal stiffness, and the coefficient of the classical Coulomb friction and viscous damping elements representing the various dissipative forces in the system. The values obtained for these parameters are validated by comparisons with previous results based on an alternative identification method applicable only to periodic tests and by comparisons with experimental data obtained during earthquake simulation tests and harmonic steady-state tests. The proposed identification approach works well for periodic sinusoidal and triangular tests, earthquake simulation tests, and white noise tests with table root mean square above 10% of gravity.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This work was supported by the National Science Foundation through the NEES program, Grant No. NSFCMS-0217293; the Englekirk Center Board of Directors and NEESinc through a NEES facility enhancement project, and Lawrence National Laboratory (with Dr. Dave McCallen as research manager). These sources of support are gratefully acknowledged. The writers want to thank Prof. José Restrepo (U.C. San Diego), Prof. Tomaso Trombetti (University of Bologna, Italy) for their significant contributions during the shake-down and characterization tests that produced the data used in this study. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the writers, and do not necessarily reflect those of the sponsors.
References
Clark, A. (1992). “Dynamic characteristics of large multiple degrees of freedom shaking tables.” Proc., 10th World Conf. on Earthquake Engineering.
Conte, J. P., and Trombetti, T. L. (2000). “Linear dynamic modeling of a uniaxial servo-hydraulic shaking table system.” Earthquake Eng. Struct. Dyn., 29(9), 1375–1404.
Crewe, A. J., and Severn, R. T. (2001). “The European collaborative programme on evaluating the performance of shaking tables.” Philos. Trans. R. Soc. London, Ser. A, 359, 1671–1696.
Hwang, J. S., Chang, K. C., and Lee, G. C. (1987). “The system characteristics and performance of a shaking table.” NCEER Rep. No. 87–0004, National Center for Earthquake Engineering Research, State Univ. of New York at Buffalo, Buffalo, N.Y.
Kusner, D. A., Rood, J. D., and Burton, G. W. (1992). “Signal reproduction fidelity of servohydraulic testing equipment.” Proc., 10th World Conf. on Earthquake Engineering, Rotterdam, The Netherlands, 2683–2688.
Ozcelik, O., Luco, E. J., Conte, J. P., Trombetti, T. L., and Restrepo, J. I. (2007). “Experimental characterization, modeling and identification of the UCSD-NEES shake table mechanical system.” Earthquake Eng. Struct. Dyn., in press.
Rinawi, A. M., and Clough, R. W. (1991). “Shaking table-structure interaction.” EERC Rep. No. 91/13, Earthquake Engineering Research Center, Univ. of California at Berkeley, Berkeley, Calif.
Shortreed, J. S., Seible, F., Filiatrault, A., and Benzoni, G. (2001). “Characterization and testing of the Caltrans seismic response modification device test system.” Philos. Trans. R. Soc. London, Ser. A, 359, 1829–1850.
Thoen, B. K. (2004). 469D seismic digital control software, MTS Corporation.
Thoen, B. K., and Laplace, P. N. (2004). “Offline tuning of shaking table.” Proc., 13th World Conf. on Earthquake Engineering, Vancouver, B. C., Canada, Aug. 1–6, Paper No. 960.
Trombetti, T. L., and Conte, J. P. (2002). “Shaking table dynamics: Results from a test analysis and comparison study.” J. Earthquake Eng., 6(4), 513–551.
Twitchell, B. S., and Symans, M. D. (2003). “Analytical modeling, system identification, and tracking performance of uniaxial seismic simulators.” J. Eng. Mech., 129(12), 1485–1488.
Van Den Einde, L., et al. (2004). “Development of the George E. Brown Jr. network for earthquake engineering simulation (NEES) large high performance outdoor shake table at the Univ. of California, San Diego.” Proc., 13th World Conf. on Earthquake Engineering, Vancouver, B.C., Canada, August 1–6, Paper No. 3,281.
Williams, D. M., Williams, M. S., and Blakeborough, A. (2001). “Numerical modeling of a servohydraulic testing system for structures.” J. Eng. Mech., 127(8), 816–827.
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 134 • Issue 1 • January 2008
Pages: 23 - 34
Copyright
© 2008 ASCE.
History
Received: Feb 9, 2007
Accepted: May 30, 2007
Published online: Jan 1, 2008
Published in print: Jan 2008
Notes
Note. Associate Editor: Lambros S. Katafygiotis
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.