Seismic performance of steel braced frames with self‐centering buckling‐restrained brace utilizing superelastic shape memory alloys

Summary Buckling‐restrained braced frame (BRB) is one of the newest seismic force‐resisting systems used in buildings. However, one of the requirements for designing a structure is to provide a ductility behavior of structures to dissipate earthquake energy and to avoid residual drifts. These days, self‐centering seismic lateral force‐resisting systems have drawn attention due to their potentials to solve the above mentioned issues. On the other hand, shape memory alloys (SMAs) are characterized by unique superelastic behavior, which enables the material to recover its original shape after experiencing large deformations. The goal of this study is to assess BRBs whose ductility are improved by utilizing SMA. Nonlinear time history and incremental dynamic analysis techniques are applied to investigate the behavior of the two frames with different stories (four and eight stories) under different ground motion records. The results showed that utilizing BRB made of hybrid steel and SMA resulted in increasing ductility of the structure and decreasing residual displacements of the structures.