Vibration-control mechanism and damping performance of the eccentric connected structure-control system

Abstract

Installing energy-dissipation devices in connected structures can greatly enhance their seismic performance. Currently, two-dimensional models are extensively studied, but they fail to fully capture the effects of eccentricities on the control efficiency of connected structures. To address this limitation, this study proposes a series-parallel rigid plate model that can simulate an eccentric connected structure-control system (ECSCS), enabling a comprehensive investigation. The study begins by deriving the equations of motion for the simplified model. It then analyzes the effects of energy-dissipation story (EDS) eccentricities, translational frequency ratio, and translational damping ratio on the torsional direction factor and torsional energy ratio at each mode frequency, specifically considering x-direction eccentricity. The subsequent exploration reveals the vibration-control mechanism and optimizes the EDS parameters using a multi-objective particle swarm optimization (MOPSO) algorithm. Additionally, the control effects for various eccentricity ratios are compared. The findings demonstrate that modifying the parameters of the EDS can effectively reduce translational-torsional coupling effects and torsional energy ratios in each substructure. While the addition of EDS may increase the top rotation acceleration and inter-story drift ratio in some cases, the peak values of other dynamic responses decrease. Moreover, adjusting the span of the EDS significantly increases the translational-torsional frequency ratio and enhances the torsional resistance of the structure. The study also emphasizes the importance of considering the impact of an asymmetric lower tower on the control effect of ECSCS. In most cases, lower towers with the same eccentricity demonstrate superior control due to the contribution of EDS.