Simultaneous excitation and parameter identification for non-linear structural systems

• Published in: Journal of Vibroengineering Vol. 19; no. 6; pp. 3968 - 3980
• Main Authors: Wan, Zhimin, Wang, Ting, Huang, Qibai, Zheng, Weiguang, Gu, Feng
• Format: Journal Article
• Language: English
• Published: 01.09.2017
• ISSN: 1392-8716; 2538-8460
• DOI: 10.21595/jve.2017.17576

In this paper, an algorithm is proposed for simultaneous excitation and parameter identification for non-linear system in state space. The algorithm is based on the sequential application of extended Kalman estimator for non-linear structural parameters and the weighted least squares estimation for unknown excitations. The state and parameter are reformed into the augmented state, and the state space equations are non-linear associated with the augmented state. With the first-order Taylor expansion for nonlinear system and approximately linear minimum-variance unbiased estimation, a recursive algorithm is derived where the identification of the augmented state and the excitation are interconnected. Two numerical examples which identify uncertain parameters of a 3-DOF Duffing-type system and a four-story hysteretic shear-beam building subject to unknown random excitation respectively, are conducted to demonstrate the effectiveness of the proposed approach.