Tubular Web RBS connection to improve seismic behavior of moment-resisting steel frames

A new type of reduced beam section (rbs) connection, called tubular web rbs (tw-rbs), is proposed in this research. tw-rbs is made by replacing a part of web with a tube at the expected location of the beam plastic hinge. in addition to an analytical study, the proposed section is numerically studied under cyclic load using abaqus finiteelement software, and a test specimen is used for the calibration of numerical results. the results show that using tw-rbs not only creates a ductile fuse far from the beamto- column connection components, but it also increases story drift capacity up to 9%. furthermore, the tubular web, like corrugated sheet, can improve both the out-of-plane stiffness of the beam longitudinal axis and the flange stability condition due to the smaller width-to-thickness ratio of the beam flange in the plastic hinge region. thus, the tubular web improves lateral-torsional buckling stability of beam. on the other hand, the tubular web provides a better condition than other accordion web with sharp corners in terms of low-cycle fatigue, because change of direction of strain in arc shape of the tubular web section is smaller than the accordion web with sharp corners.