Damping Performance and Optimal Design of Mid-Story Isolation System with Tuned Inerter Damper

Tuned inerter damper (TID) has been introduced and investigated to improve the damping performance of the mid-story isolation system in this study. TID in this novel system is arranged into the mid-story isolation system to utilize its weak transition layer enhancing damping effects. To achieve the best results, the closed-form optimization solutions of TID based on vibration mode are proposed to present optimal design. As such, case studies have been conducted with the different arrangements of the isolation layer with TID and the damping effects of mid-story isolation system have been significantly improved. The presented random analysis results also show the superiority of the proposed novel system when compared with the traditional mid-story system in terms of multiple control indexes, e.g. the top displacement of the substructure, the relative displacement of the isolation layer and the top absolute acceleration of the superstructure. Mostly, the seismic peak responses of mid-story isolation system are significantly suppressed with the proposed optimal design parameters of TID, especially for the relative displacement of isolation layer. © 2025 World Scientific Publishing Company.