Analysis of key parameters influencing performance for assembled aluminum alloy buckling-restrained braces

Buckling-restrained braces (BRBs) are widely used in engineering practice as both load-bearing and energy-dissipating components. However, the application of traditional BRBs is often limited by their self-weight, particularly in long-span structures. To address this limitation, this study proposes a novel BRB configuration that combines a redesigned structural form with lightweight aluminum alloy material. A nonlinear finite element model of the proposed aluminum alloy BRB was developed following validation against similar experimental results and modeling approaches. The effects of the shape and amplitude of the first two initial geometric imperfections of the inner core, as well as the clearance between the inner core and the restraining members, on the energy dissipation capacity and stress distribution were systematically analyzed. Finally, based on the numerical results, a recommended range for the restraining length ratio under various clearance conditions is proposed to guide design optimization.