Experimental investigations on seismic control of cable-stayed bridges using shape memory alloy self-centering dampers

Abstract

This paper presents the experimental investigations of a novel self-centering damper (SCD) for controlling seismic responses of cable-stayed bridges. The damper is fabricated employing the super-elasticity effect and energy dissipation characteristics of shape memory alloy wires. Within super-elastic range, a damping force model is derived and verified based on the constitutive model of shape memory alloy wires. One reduced-scale cable-stayed bridge model is designed to investigate its seismic control performance. Two different system configurations of the cable-stayed bridge model are considered, including the without control state and incorporating with the SCD between the tower and the deck. Seismic behavior of different cable-stayed bridge systems is then evaluated via shaking table tests under different ground excitations. Experimental results show the effectiveness of the SCD. The accelerations and the relative displacements of the tower reduce obviously due to the energy dissipation of the SCD. Relative displacements of the deck decline dramatically because of the connection of the SCD. Moreover, the strain responses also indicate the drop of the bending moment in the tower.