Optimization of Tuned Mass Damper Inerter Systems for Seismic Control of Base-Isolated and Fixed-Base Structures

In this study, the application of enhanced inerter-based control devices is considered to improve broadband vibration control, including optimizing the design of a base-isolated structure featuring a supplementary tuned mass damper inerter (TMDI). The primary response of an undamped single degree of freedom (SDOF), considering relative displacement, velocity, relative accelerations, and force transmitted to the ground, is investigated. Optimal TMDI parameters are evaluated using the hybrid optimization technique, employing numerical search methods. Subsequently, a curve-fitting approach is utilized to derive explicit formulations for TMDI parameters based on the numerical search results and optimal parameters determined through fixed-point theory. The proposed equations demonstrate minimal inaccuracies, rendering them valuable for damped system design. In addition, the primary system’s damping minimally impacts the TMDI’s optimal damping ratio but significantly affects its optimum tuning frequency. Furthermore, the optimally developed TMDI is applied to an SDOF-damped system with both fixed and flexible bases as a supplemental damper. The study extends to incorporate multi-degree-of-freedom (MDOF) systems, considering three different case study structural models equipped with TMDIs. The analysis of twenty ground motion excitations on these models highlights the efficiency of the optimal TMDI in controlling seismic behaviors. Particularly, the maximum responses are observed in a nine-story benchmark structure under twenty real ground motion seismic excitations, underscoring the utility of the optimized TMDI in seismic control applications.