An experimental and numerical investigation of the cyclic performance of a smart self-centering bracing system

Buildings with traditional structural systems experience large residual deformation after an earthquake, and often lose their serviceability and need to be demolished incurring huge economic losses. In order to resolve this issue, various smart structural systems have been developed by many researchers. One such system is the novel Piston Based Self-Centering bracing (PBSC) system. This study investigates the cyclic performance of this bracing system experimentally to predict its load-deformation response during seismic events. This newly developed bracing system employs Nickel Titanium (NiTinol) based Shape Memory Alloy (SMA) bars inside a sleeve-piston assembly for its self-centering mechanism. During cyclic tension-compression loading, the bars are pulled from opposite directions in order to avoid compressive loading on them. The energy dissipation is achieved through nonlinear load deformation hysteresis. Furthermore, the PBSC bracing system is designed to be fully buckling restrained. The system exhibits flag shaped force deformation hysteresis. The experimental results are compared with previously generated numerical results, where very good agreement is achieved.