Performance optimization of inter-storey isolation systems with negative stiffness devices for super high-rise buildings

To enhance the seismic isolation performance of inter-storey isolation systems in super high-rise buildings, this study proposes an improved inter-storey isolation system integrated with negative stiffness devices (IIS-NSD). The system parameters are optimized using fixed-point theory combined with H₂ optimal control methods. A two-degree-of-freedom dynamic model is established, introducing correction factors to improve optimization accuracy. Nonlinear time-history analyses under near-fault and far-field ground motions are conducted to systematically evaluate the response control capabilities of the IIS-NSD system under various conditions. Results indicate that the IIS-NSD system significantly improves isolation performance under strong nonlinear seismic scenarios. The optimized IIS-NSD system substantially reduces structural acceleration and inter-storey displacement, with maximum displacement reductions exceeding 40 % and peak acceleration decreases averaging over 30 %. Meanwhile, the system effectively suppresses excessive structural deformation during nonlinear phases and enhances overall energy dissipation capacity. Notably, under strong near-fault earthquakes, the system demonstrates more stable control effects and exhibits good robustness against uncertainties in seismic input.