For steel structures, what is the primary advantage of using Buckling Restrained Braces (BRBs) compared to conventional braces?

The primary advantage of using Buckling Restrained Braces (BRBs) compared to conventional braces in steel structures is their ability to provide stable and symmetrical hysteretic behavior under cyclic loading, meaning they can dissipate energy effectively in both tension and compression without significant strength degradation due to buckling. Conventional braces, when subjected to compression, are prone to buckling, which drastically reduces their load-carrying capacity and energy dissipation capability. This buckling behavior results in pinched hysteretic loops, indicating a loss of energy dissipation. BRBs, on the other hand, are designed to prevent buckling by encasing a steel core within a restraining mechanism, typically a steel tube filled with concrete. This restraining mechanism allows the steel core to yield in both tension and compression without buckling, resulting in full and stable hysteretic loops. This symmetrical behavior enables BRBs to dissipate significantly more energy than conventional braces during an earthquake, leading to improved seismic performance of the structure. The predictable and stable behavior of BRBs also simplifies design and analysis, as the brace's capacity is consistent regardless of the direction of loading.