Seismic Performance and Sustainability of BRB and SMA-Braced Structures Under Incremental Dynamic Analysis

Buckling restrained braces (BRBs) are widely used for seismic resistance due to their efficiency and stable structural behaviour. However, despite their high energy dissipation capacity, BRBs retain residual strains, leading to permanent deformations that require extensive post-earthquake repairs. To address this limitation, shape memory alloys (SMAs) have emerged as an innovative solution. SMAs exhibit superelasticity and shape memory effects, enabling self-centering behaviour that reduces residual deformation and enhances seismic resilience. This study compares the seismic performance of structures equipped with BRBs and those using iron-based and nickel-based SMAs. Using SeismoStruct, incremental dynamic analysis was conducted on a seven-story structure with various bracing configurations. Results show that iron-based SMAs achieve lower permanent displacements than nickel-based SMAs while maintaining excellent energy dissipation. Although SMA-braced structures have slightly higher peak displacements than BRBs, they eliminate permanent deformation, making them a promising solution for sustainable, earthquake-resistant design by reducing repair needs and construction waste.