Seismic design of rib-reinforced steel moment connections based on equivalent strut model

This paper describes a seismic design procedure for rib-reinforced steel moment connections based on an equivalent strut model. It is shown from the results of finite-element analysis that the force transfer mechanism in the rib connections is completely different from that predicted by the classical beam theory and that a diagonal strip in the rib acts as a strut. By treating the rib as a strut, an equivalent strut model that could be used as the basis of a practical design procedure is proposed first. A step-by-step design procedure is then recommended based on the proposed model.