Inverse system method for dynamic loads identification via noisy measured dynamic responses
Abstract
Purpose
The purpose of this paper is to focus on the influences of the uncertain dynamic responses on the reconstruction of loads.
Design/methodology/approach
Based on the assumption of unknown-but-bounded (UBB) noise, a time-domain approach to estimate the uncertain time-dependent external loads is presented by combining the inverse system method in modern control theory and interval analysis in interval mathematics. Inspired by the concept of set membership identification in control theory, an interval analysis model of external loads time history, which is indeed a region or feasible set containing all possible loads being consistent with the bounded structural acceleration responses is established and further solved by two interval algorithms.
Findings
Unlike traditional loads identification methods which only give a point estimation, an interval estimation of external loads time history, which is a region containing all the possible loads being consistent with the uncertain structural responses, is determined. The correlation characteristics among the responses of acceleration, velocity, and displacement are also discussed in consideration of the UBB uncertainty.
Originality/value
For one hand, the solution of the inverse problem in original system is transformed to the solution of the direct problem in inverse system; for another, the authors deal with the uncertainty by use of interval analysis method, and the identified interval process, which contains any possible external loads time history being consistent with the bounded structural responses can be approximately obtained.
Keywords
Acknowledgements
The authors would like to thank the National Nature Science Foundation of China (No.11372025, 11432002), and the Defense Industrial Technology Development Program (No. JCKY2013601B) for the financial supports. Besides, the authors wish to express their many thanks to the reviewers for their useful and constructive comments.
Citation
Wang, L., Wang, X. and Li, X. (2016), "Inverse system method for dynamic loads identification via noisy measured dynamic responses", Engineering Computations, Vol. 33 No. 4, pp. 1070-1094. https://doi.org/10.1108/EC-04-2015-0103
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited