Numerical comparison on the efficiency of conventional and hybrid buckling‑restrained braces for seismic protection of short‑to‑mid‑rise steel buildings

Buckling-restrained brace (BRB) is a specific kind of bracing system which has an acceptable energy dissipation behavior in a way that would not be buckled in compression forces. However, considerable residual deformations are noticed in strong ground motions as a result of the low post-yield stiffness of the BRBs. The seismic performance of a modern lateral load resisting system, which is called the hybrid BRB, and its conventional counterpart are assessed and compared in this paper. Multiple plates with different stress–strain behavior are used in the core of this new innovative system, and this is its difference with the existent BRBs. Nonlinear static and incremental dynamic analyses are carried out for three building frames with different structural heights, which use conventional and hybrid BRB systems. To carry out response history analyses, the FEMA P695 far-field earthquake record set was adopted in different hazard levels. The hybrid BRBs are shown to have superior seismic performance in comparison with the conventional systems based on the response modification factor and the damage measures including residual displacements and inter-story drift ratios.