Resettable smart dampers for multi-level seismic hazard mitigation of steel moment frames

Abstract

A main goal of supplemental control devices is to manage the energy dissipation in the system. Resettable devices have emerged as a promising control device for application to civil structures as they are effective energy dissipators. This paper presents an investigation of the ability of semi-active control methods utilizing resettable devices to mitigate structural response in the presence of hysteretic, geometric and yielding nonlinearities under various intensity level seismic hazard suites to define control efficacy and seismic hazard statistics. A major component of this research is to assess the effect of device placement on control benefit. Results show that resettable devices limited to realistic peak force/dissipation levels of ∼13% building weight are effective at limiting permanent deflections and indicate the importance of zero tracking for nonlinear systems. However, floor accelerations rise significantly as displacement is limited, and the performance improvement is not the same for all ground motions. Owing to predominantly first-mode response of the case study structure, peak and permanent drifts saw larger reductions as more device authority was placed at the base of the structure, although the best overall results distributed device authority roughly proportional to the structural storey shears. Copyright © 2003 John Wiley & Sons, Ltd.