Reduced length buckling restrained brace using steel plates as restraining segment
Buckling restrained braced frames (BRBFs) have been used as seismic load resisting system in recent years. Due to their more effective performance, BRBs have been employed to replace conventional braces in concentrically bracing frames. When compared to conventional braces, BRBs exhibit symmetric and more stable hysteretic behaviour that provide significant energy dissipation capacity and ductility. Since the manufacturing process of the BRBs is expensive and time consuming, and requires considering tight erection tolerances, they have not been commercialized as the common bracing systems in some parts of the world. In order to reach a simpler detailing, all-steel BRB with the idea of eliminating mortar have been proposed and developed in the last years. In the present paper, an innovative all-steel BRB with reduced yielding segment is proposed. In the proposed BRB, the yielding part is located at one end of the brace and steel plates are intended to act as the buckling restraining part. Analytical model is developed using a finite element software and a nonlinear cyclic analysis is performed as per the recommended loading protocol. The results show the steel plates can successfully restrain the buckling of yielding segment of BRB and thus cause the stable and symmetric hysteresis behaviour of the brace.
Ali Razavi