Bidirectional performance assessment of UFREI-isolated structures with single and multiple tuned mass dampers under earthquakes and winds

Abstract

An innovative hybrid vibration controller (HVC) composed of unbonded fiber-reinforced elastomeric isolators (UFREIs) and tuned mass dampers (TMDs) is utilized for the vibration control of an existing hospital building under the multi-hazard scenario of earthquakes and (nonconcurrent) winds. A 3-dimensional nonlinear model of the considered hospital building is analyzed. Four configurations of the HVC are investigated, wherein single or multiple TMDs are utilized, having various tuning properties and locations along the height of the building. All the various controlled and uncontrolled structures are subjected to site-specific bidirectional earthquake and wind excitations. Results reveal that the HVC with two TMDs, having favorable tuning conditions for both earthquakes and winds, are the most efficient under the multi-hazard scenario. Interestingly, the increase in the TMD mass ratio always improves the performance of the HVC under wind excitations, however under earthquakes, it may also result in enhanced deterioration of HVC performance in detuned conditions.