Numerical Assessment of the RBS Connection Reinforced with Stiffeners

Abstract A prevalent form of moment connection in steel frames is Reduced Beam Section (RBS) connection. Nevertheless, the utilization of this connection in deep beams is constrained by issues such as beam buckling at large displacements, leading to a decline in connection strength at high rotation. Web stiffeners can be employed as an effective method to address this problem. Five RBS connection specimens with horizontal, vertical, and diagonal stiffeners were numerically studied under cyclic loading and using the finite element method. The findings indicated that among the five techniques of reinforcement, four strategies effectively improved both the maximum and ultimate strength of the connection, while preserving the plasticity and sustaining the original position of the plastic hinge in the initial design. Out of the several ways used to strengthen the structure, the model with diagonal stiffener (Stiff-D2) had a notable impact on enhancing the performance of the RBS connection. In other words, the maximum resistant moment of the connection in this model exceeds that of the RBS connection by 4.9%.