Influence of mechanical layout of shape memory alloy damping inerter (SDI) systems for vibration control

Abstract

A shape memory alloy damping inerter (SDI) with an SMA placed in parallel with an inerter and then in serial with a spring was developed as a vibration control device, where the inerter is utilized to amplify the deformation of SMA to improve the energy dissipation capacity. However, SDI can have other mechanical layouts when an SMA, an inerter and a spring are involved, which may exhibit different control effectiveness. Moreover, explicit design methods aiming to achieve the optimal performance of the SDI systems remain unexplored. In this study, SDIs with different mechanical layouts are proposed and compared, and design method for the SDI-equipped structure is developed. Firstly, the mechanical model of a structure with SDI systems is separately established. Parametric analysis is then conducted in terms of the displacement response, acceleration response and damping enhancement effect. Selection for appropriate SDI mechanical layout can be identified based on parametric analysis results. Additionally, design method based on maximizing the damping enhancement effect to fully develop the energy dissipation capacity of the SMA under the target structural response mitigation ratio is proposed. The performance of the optimal designed SDI-equipped structures is finally evaluated in the time-domain. Results show that both the displacement and acceleration responses of the SDI-equipped structures can be effectively mitigated by using the proposed optimal design method. Among the optimized SDI systems, the energy dissipation capacity of SMA is almost similar. Different SDI systems differ in the energy dissipation characteristic. The SMA-spring-paralleled SDI exhibits minimum damping force, indicating a better damping enhancement effect and less material demand of SMA than the other SDI systems.