OPTIMUM DESIGN OF A RE-CENTERING DEFORMATION-AMPLIFIED SMA DAMPER

This paper presents an innovative re-centering deformation-amplified shape memory alloy (SMA) damper (RDASD) by utilizing the superelastic property of SMA materials. The damper can amplify the displacement deformation according to practical engineering requirements and then fully exploit the energy dissipation capacity of the superelastic SMA materials by restricting the amplified displacement. A theoretical model of the RDASD was proposed and then cyclic tensile-compressive tests were conducted to verify the accuracy of the model. Based on the flag force-restoring model of the SMA material, the influences of pre-deformation, superelastic displacement, stiffness and length of the SMA wires on the energy dissipation coefficient of the damper were analyzed. To achieve optimal energy consumption and seismic control effect, the design criterion and performance optimization method of the damper were presented. Finally, time-history analysis with and without this damper on a 3-layer steel frame was presented, which validated the control effect of the damper.