A novel response-amplified shape memory alloy-based damper: Theory, experiment and numerical simulation

The energy dissipation capacity of shape memory alloy (SMA) dampers can be effectively improved owing to the success of response amplification technology. However, conventional response-amplified SMA dampers for building structures still face a risk of failure during extremely rare earthquake events. In this study, a novel response-amplified SMA damper (RASD) is proposed with the advantages of fully exploiting the energy dissipation characteristics of SMA materials and avoiding material failure. First, the components, configuration, and working principles of the proposed damper were described. Subsequently, a restoring-force model of the RASD was established, and its accuracy was verified through cyclic loading tests. Finally, seismic performance mitigation of a single-degree-of-freedom (SDOF) system under different hazard levels was conducted to evaluate the effectiveness and advantages of the proposed RASD quantitatively. The results reveal that the RASD has a good force amplification effect and excellent damping enhancement effect and thus conspicuously mitigates the seismic response of the SDOF system. In particular, the proposed RASD can effectively reduce the force and displacement demand of SMA materials without the risk of SMA failure, while significantly mitigating the structural response.