Seismic performance of two-story three-bay reinforced concrete frame equipped with K-configured buckling restrained braces

Abstract

This study presented experimental and numerical investigations into the seismic performance of reinforced concrete (RC) frames equipped with buckling restrained brace (BRB) systems in the central span. The study evaluated the effectiveness of the K-configured BRB system in strengthening the RC frame for engineering construction applications in the seismic region. A 1/3-scaled, three-span, two-story, RC frame was designed in accordance with seismic design requirements and tested under low-reversed lateral cyclic loading. A finite element model of the BRB-equipped RC frame was created using ABAQUS and validated by comparing the numerical and experimental results. The validated model was also modified by removing the BRBs to create the bare RC frame. Seismic behaviors of the bare and RBR-equipped RC frames were numerically examined and compared in terms of failure modes, hysteretic response, ductility, energy dissipation, strength degradation, and stiffness deterioration. The results indicated that the BRB-equipped RC frame achieved a plastic hinge failure mechanism at the beam ends with no severe concrete damage in the supporting columns. Furthermore, the use of the K-shaped BRB in the central span improved the load-carrying capacity by up to 80% and the energy dissipation capacity by up to 50%. Parametric studies were also conducted to investigate the influence of critical design parameters and provide design suggestions for potential improvement in the RC frame's ductility and energy dissipation capacity.