Identification of model-free structural nonlinear restoring forces using partial measurements of structural responses. Issue 1 (January 2017)

• Record Type: Journal Article
• Authors: Lei, Y; Luo, SJ; He, MY
• Other Names: Ren Wei-Xin guest-editor.; Wang Zuo-Cai guest-editor.; Ru Jiping guest-editor.
• Is Part Of: Advances in structural engineering. Volume 20:Issue 1(2017)
• Page Start: 69
• Page End: 80
• Publication Date: 2017-01
• Subjects: extended Kalman filter -- nonlinear restoring force -- nonlinear system identification -- partial measurements -- power series polynomials; Structural engineering -- Periodicals; Construction, Technique de la; Structural engineering; Periodicals; 624.1
• DOI: 10.1177/1369433216646006
• Languages: English
• ISSNs: 1369-4332

Abstract

Identification of nonlinear structural system is an important but challenging task for structural health monitoring. Due to the complexities of structural nonlinearities, it is hard to establish proper mathematical models for some structural nonlinear behaviors. Moreover, only partial structural responses can be measured in practice; it is essential to conduct identification of nonlinear structural systems using only partial measurements of structural responses. To cope with these issues, an algorithm is proposed in this article for the identification of some model-free structural nonlinear restoring forces using only partial measurements of structural responses. First, an equivalent linear structural system is introduced for the identification of the locations of structural nonlinearities. Then, a model-free structural nonlinear restoring force is approximated by a power series polynomial. The unknown coefficients of the power series polynomials together with other structural parameters are identified by the extended Kalman filter so that the characteristics of the behaviors of the model-free of nonlinear restoring forces can be identified. Some numerical examples including the identification of two nonlinear multi-story shear frames and a planar nonlinear truss with different structural nonlinear restoring forces are used to validate the proposed algorithm.