Dissipative Exoskeletons Based on Self-centering SMA Braces for Seismic Retrofit of RC Buildings

This article presents the design and assessment of dissipative exoskeletons based on recentering shape memory alloy (SMA) dampers for the seismic retrofit of RC buildings. Although many studies have been presented in the literature on SMA bracing systems, most of them are devoted to experimental and numerical investigations on small-scale SMA devices or brace compo-nents. Only a few studies focus their attention on the application of SMA-brace devices to full-scale RC buildings. This paper focuses on evaluating the effect of using self-centering shape memory alloy dampers for buckling-restrained braces in dissipative exoskeletons applied for the seismic retrofit of a reinforced concrete (RC) school building structure. A design method has been implemented to size the SMA dampers to be placed on selected spans and stories of the exoskeletons. The effectiveness of the design procedure has been demonstrated by nonlinear time-history analyses under different sets of earthquake-strong ground motions.