Seismic performance of RWS moment connections to steel box-columns and H-beams with general sections

In this study, full-scale seismic testing and 3D finite element analysis were carried out on reduced web section (RWS) connections. A steel H-beam-to-box-column connection was designed to have two parallel long openings in the beam web. The opening was rectangular with semicircles at both ends. The design used the adjacent beam flanges to take shear forces with the beam web with openings, which made it possible to apply RWS connections with general sections. The design parameters were then selected to delay the occurrence of local plate buckling in the beam flanges near the beam web with openings, which ensured that the connections developed sufficient plastic deformation before reaching the maximum strength. The results showed that the refined design could move the plastic hinges of the connections away from the column faces. Moreover, after a complete loading cycle with a drift angle of 4% rad, the connections still had a moment strength of >80% of the beam plastic moment strength. The connection performance met the AISC seismic requirement. This design refinement makes it possible to further apply RWS connections to steel moment frames in building retrofits.