Multi-hazard performance evaluation of the negative stiffness damped outrigger hybrid system subjected to crosswind and seismic excitation

Abstract

The negative stiffness damped outrigger (NSDO) system have demonstrated the effectiveness in mitigating excessive vibrations. However, previous studies have focused on optimizing the NSDO hybrid system subjected solely to seismic excitation, neglecting the multi-hazard of winds and earthquakes. To gain insight into such system, this paper proposes a multi-performance economical optimization-based sensitivity analysis procedure (MPEOSAP) to explore the multi-hazard performance of the NSDO hybrid system. The simplified model of the hybrid system was established. The performance objective was established by combining crosswind-induced acceleration and seismic harmful inter-story drift, and the economic objective was the outrigger damping cost. The POF was utilized to address optimization objectives. An analysis was conducted on the sensitivity of the objective value to the total negative stiffness. The optimal parameters were evaluated under simulated crosswind and actual earthquake. The results indicate compared to the CO system, all hybrid systems reduce crosswind acceleration by approximately 68%–78% and the seismic harmful inter-story drift by 40%–61%. While the DNHS system could perform better with adequate negative stiffness, the proposed CNHS and NCHS systems demonstrate greater effectiveness with limited negative stiffness.