Seismic response reduction of elastoplastic structures with inerter systems

Abstract

Several studies have focused on the mechanism of an inerter, which is an acceleration-dependent two-terminal element, while other studies have concentrated on developing a design method for a structure with an inerter system. However, to the best of the authors’ knowledge, the nonlinearity of the primary structure has never been considered, leading to uncertainty in design results. Particularly when a structure experiences a rare earthquake, its safety becomes uncertain because of the deterioration of structural stiffness. Therefore, this study focused on seismic control of an elastoplastic structure and explored a demand-oriented design method for it. In this paper, the basic concept of an inerter system is firstly introduced. Then, various aspects of the design method are elaborated, including the performance index, design parameters, and optimal equation for elastoplastic single-degree-of-freedom (SDOF) and multiple-degree-of-freedom (MDOF) structures. Specifics of the design procedure are also described. A parameter distribution pattern is employed to reduce the computation cost for the MDOF structure. Subsequently, an elastoplastic SDOF structure and a two-dimensional steel benchmark model are employed to carry out seismic design, and the parameters of the inerter systems are obtained. Nonlinear time history analysis results indicate that the performance of structures with inerter systems satisfies the target requirements, thereby illustrating the effectiveness of the proposed design procedure. The results demonstrate that the proposed method considers the nonlinearity of a structure with an inerter system subjected to an earthquake, which improves the reliability of the seismic design and the safety of the structure. The proposed design method can be used to design structures with inerter systems that achieve their expected performance and minimize the control cost.