Title: Identification of external force for slender flexible structures via sparse modelling with an under-relaxation scheme

Authors: Weijie Song; Qiao Qian; Yoshiki Nishi

Addresses: Department of Mechanical Engineering, Material Science, and Ocean Engineering, Graduate School of Engineering Science, Yokohama National University, Yokohama, Kanagawa, Japan ' School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Minhang, Shanghai, China ' Department of Systems Design for Ocean-Space, Faculty of Engineering, Yokohama National University, Yokohama, Kanagawa, Japan

Abstract: This study proposes a method for identifying unknown external forces that act on slender flexible bodies. In this method, the external force is represented as an expansion in the Chebyshev polynomials. The expansion coefficients are determined to minimise the number of non-zero coefficients and the difference between the measured and estimated quantities. An under-relaxation scheme is applied to enhance the robustness of computations for the identification. Static and dynamic beam problems are solved using the method to examine how well it can reconstruct the external forces. Numerical computations and analyses of the results demonstrate that the method generally produces a satisfactory external force reconstruction, and its accuracy is sensitive to the choice of measuring device.

Keywords: external force identification; Chebyshev polynomials; sparse modelling; under relaxation; beam.

DOI: 10.1504/IJMIC.2021.122470

International Journal of Modelling, Identification and Control, 2021 Vol.38 No.1, pp.59 - 73

Received: 14 Nov 2020
Accepted: 23 Mar 2021

Published online: 04 Apr 2022 *

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