Seismic performance of steel beam-to-column moment connections with tapered beam flanges

This work elucidates experimentally and numerically the behavior of steel beam-to-column moment connections proposed by widening and tapering the portion of beam flanges to increase the ductility and strength of the connection used in moment-resisting frames. Effectiveness of the tapered beam flange and the extent to which geometrical variables of the tapered beam flange affects the connection behavior were examined, based on a parametric study using finite element analysis. Additionally, seven full-scale specimens were tested to clarify their cyclic performance. All of the proposed tapered beam flange specimens, using either the column-tree full welded connection or the web-bolted flange-welded connection, achieved satisfactory ductile behavior by forming a plastic hinge in the beam section away from the column face. Extensive yielding, which occurred in the tapered zone of the beam section, resulted in stable energy dissipation. Based on the parametric study and experimental results, we recommend design parameters and a related procedure for practical design applications.