Double reduced beam section connection

Abstract

In this paper, a novel beam-to-column steel moment connection, named “double reduced beam section (DRBS)” is introduced and the seismic performance of the connection is assessed using finite element modeling. The connection is composed of double dog bone sections close to the column face to widen the plastic hinge region; consequently, reducing the resultant equivalent plastic strain. The region between the two reduced beam sections is laterally connected to the slab to protect the plastic hinge from lateral torsional buckling. A parametric study was conducted on the influence of cut parameters on the connection's seismic behavior. The results showed that, following the limitations and guidelines stated in this research, the DRBS connection exhibits outstanding hysteresis behavior. The deformation capacity of the connection was increased up to 40% in the DRBS connection, compared to the common reduced beam section (RBS) connection. Plasticization of both reduced beam sections postponed the failure buckling modes, resulting in 50 to 75% increase in the absorbed seismic energy before buckling, compared to the traditional RBS connection. Moreover, adding a second cut to the ordinary RBS connection distributed the strains over the two reduced sections, leading to 35 to 60% reduction in the equivalent plastic strain at the reduced sections, at 6% inter-story drift.