Seismic retrofit of RC buildings using Buckling-Restrained Shear-Yielding Aluminium Dampers

This study presents a numerical and analytical investigation of the hysteretic response of bucklingrestrained aluminium shear-yielding dampers (BRASYPs), developed as lightweight and efficient seismic energy dissipation devices. Aluminium’s high ductility and favourable strength-to-weight ratio make it particularly suitable for applications in both new construction and seismic retrofitting of existing buildings. Finite Element Models (FEM), calibrated against experimental data, were employed to simulate the cyclic behaviour of dampers with both rectangular and hourglass geometries. The analyses incorporated material and geometric nonlinearities, as well as initial imperfections, to capture instability phenomena. Results show that unrestrained aluminium dampers experience significant strength degradation due to out-of-plane buckling, especially at moderate drift levels, leading to reduced energy dissipation capacity. Conversely, the inclusion of lateral buckling inhibitors ensures stable hysteresis loops, improved shear strength, and a more uniform distribution of plastic strains. Parametric studies highlight that increased aspect ratios enhance the ultimate strength and energy dissipation per unit volume, with BRASYP models achieving up to 31% higher resistance compared to their unrestrained counterparts. These findings confirm the effectiveness of buckling-restrained aluminium dampers as reliable and durable devices for seismic protection, offering a viable alternative to traditional steel-based systems.