General Realization Algorithm for Modal Identification of Linear Dynamic Systems
Publication: Journal of Engineering Mechanics
Volume 134, Issue 9
Abstract
The general realization algorithm (GRA) is developed to identify modal parameters of linear multi-degree-of-freedom dynamic systems subjected to measured (known) arbitrary dynamic loading from known initial conditions. The GRA extends the well known eigensystem realization algorithm (ERA) based on Hankel matrix decomposition by allowing an arbitrary input signal in the realization algorithm. This generalization is obtained by performing a weighted Hankel matrix decomposition, where the weighting is determined by the loading. The state-space matrices are identified in a two-step procedure that includes a state reconstruction followed by a least-squares optimization to get the minimum prediction error for the response. The statistical properties (i.e., bias, variance, and robustness to added output noise introduced to model measurement noise and modeling errors) of the modal parameter estimators provided by the GRA are investigated through numerical simulation based on a benchmark problem with nonclassical damping.
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Acknowledgments
Support of this research by the National Science Foundation, Grant No. NSFDMI-0131967, under a Blue Road Research STTR Project on which UCSD was the principal subcontractor is gratefully acknowledged. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the writers and do not necessarily reflect those of the National Science Foundation.
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Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 134 • Issue 9 • September 2008
Pages: 712 - 722
Copyright
© 2008 ASCE.
History
Received: Nov 3, 2006
Accepted: Feb 25, 2008
Published online: Sep 1, 2008
Published in print: Sep 2008
Notes
Note. Associate Editor: Lambros S. Katafygiotis
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