Global Seismic Performance Factors of Bucklingrestrained Braced Frames with Ductile Connections

Buckling-Restrained Braces (BRBs) have good ductility and sufficient energy dissipation capacity through inelastic behavior and are limited to a rigid connection. However, the global performance of Buckling-Restrained Braced Frames (BRBF) is subjected to local strength and ductility. In this paper, a ductile connection was applied to the BRBF to improve global performance. According to some reports on the good deformation capability of Reduced Beam Section (RBS) and Top-Flange Beam (TFB) splices rotatable hinge connections, the global ductility and structural performance of BRBFs with ductile connections can be improved. Therefore, we carried out our research on the relationship of global and local ductility of BRBF and analyzed the parameters, including three weak depths of RBS connections and two strength of inner cores of BRBs. Furthermore, we investigated the best approaches for calculating global seismic performance factors (response modification coefficient (R), overstrength factor (Ω0), deflection amplification factor (Cd), and ductility reduction factors (Rμ)). We also evaluated the global seismic performance factors of BRBFs with ductile connections using the global structural ductility based on nonlinear static pushover analyses. The results can help establish global seismic performance factors of BRBFs with ductile connections.