Finite element model updating of flexural structures based on modal parameters extracted from dynamic distributed macro-strain responses

Abstract

This article presents a novel strategy for finite element model updating of flexural structures. The method is based on modal parameters extracted from dynamic distributed macro-strain responses. The objective function that comprised low-order modal macro-strain and frequency was established first, while local bending stiffness, density, and boundary conditions of structures can be selected as the design variables. Both numerical simulation and experiment were conducted to verify the effectiveness of the proposed method. The long-gauge macro-strain sensors chosen in this article are first addressed, and the fundamental sensing properties of the macro-strain sensors confirm great dynamic measurement capacity. Simulation and experimental results show that both the local parameter (bending stiffness) and the global parameters (mass density and rotational stiffness of support) can be well identified. Notably, the updated finite element model can predict local response modal macro-strain and global response (frequency and displacement mode) because the local information-sensitive index and global information-sensitive index are included in the objective function. Therefore, the proposed finite element model updating strategy constitutes a new alternative in performance assessment of flexural structures.