Enhancement of Seismic Resilience of Structures With Tuned Mass Damper Inerter by Using Effective Damping Ratio

Abstract

This study investigates the performance of a tuned mass damper inerter (TMDI) in enhancing the seismic performance of structures by focusing on the concept of effective damping ratio (EDR) and its enhancement through the effective damping ratio enhancement (EDRE) approach. An analytical model is developed for a single‐degree‐of‐freedom system subjected to stochastic excitation, from which closed‐form expressions are derived to identify optimal design parameters, including frequency ratio, damping ratio, and mitigation ratio. The proposed formulation provides a direct way to quantify how the TMDI contributes to the overall damping of the system and how this contribution can be maximized for improved response control. The analytical results are validated against numerical optimization, showing close agreement and, in many cases, improved accuracy of the closed‐form solutions. A detailed parametric investigation is carried out to understand the influence of key parameters such as inertance‐to‐mass ratio, structural damping, and detuning on system behavior. The approach is then extended to multi‐degree‐of‐freedom base‐isolated structures and evaluated under both stochastic excitations, modeled using the Kanai–Tajimi spectrum, and recorded near‐fault and far‐field ground motions. The results demonstrate that TMDI systems can significantly reduce structural responses, with the EDR and EDRE playing a central role in governing performance. The effectiveness of the EDRE mechanism is found to depend on the level of inherent structural damping, becoming more pronounced within specific damping ranges. Overall, the study presents a physically transparent and computationally efficient framework for designing TMDI systems to enhance seismic resilience in both conventional and base‐isolated structures.