Optimal design and performance of inter-story isolation system with inerter damper considering soil–structure interaction under near-fault pulse-like ground motions

The study investigates the optimal seismic performance of inter-story isolation system (IIS) with tuned inerter damper (TID) and tuned mass damper inerter (TMDI), considering soil–structure interaction. Simplified 6-degree-of-freedom models for two control systems are developed to analyze the seismic response variations of the systems under stationary white noise excitation. Frequency and damping parameters are optimized based on objective functions related to displacement and acceleration. The analysis also explores the effects of model parameters on optimum design. A comparison is made between the seismic responses of IIS with and without TID/TMDI under 34 near-fault pulse-like ground motions (NPGMs) through time history analysis. The results demonstrate that TID and TMDI effectively control acceleration and displacement responses of the systems. Notably, NPGM characteristics significantly influence control effectiveness, which should be carefully considered in design. It is highlighted that this optimal design strategy is applicable across various soil conditions.