A novel SSI-based optimization framework for non-traditional TMDI system under near- and far-fault ground motions

Previous studies on the optimal parameter selection of non-traditional tuned mass damper inerter (N-TMDI) system have predominantly adopted a fixed-base assumption. However, neglecting soil–structure interaction (SSI) in practical applications may lead to significant design inaccuracies and reduced control performance of the N-TMDI system. To overcome this limitation, a new design framework is proposed for the tuning of N-TMDI systems installed in primary structures subjected to ground motion by explicitly considering SSI effects. The novelty of the proposed approach consists of performing a hybrid GA-PSO optimization algorithm to study the efficiency of N-TMDI system under near- and far-field ground motions. This study investigates the influence of varying mass and inerter ratios on the system's dynamic response through frequency-domain analyses. The performance of the N-TMDI system is subsequently validated using real earthquake records, with a specific focus on the comparative effects of near-fault and far-fault ground motions under diverse soil conditions. The results demonstrate that the inerter mass ratio is the most dominant factor in enhancing seismic protection, significantly reducing structural displacement and acceleration compared to conventional TMD. Furthermore, the findings reveal that SSI and the distinct characteristics of ground motions significantly modify the system's control efficiency. This research confirms the robustness of the optimized N-TMDI design, providing a reliable and efficient strategy for seismic structural control under varied seismic scenarios.