An experimental and numerical investigation of reduced beam section connections with horizontal and vertical web stiffeners

Abstract

Following the 1994 Northridge earthquake, reduced beam section (RBS) was presented as a novel connection detail in the steel moment-resisting frames. Proposed detail aims to debilitate the beam at a limited interval from the connection so that less moment and force are assigned to the connection. Cutting of the beam flange, especially in the narrow sections such as IPE, leads to an increase in the potential for the web local buckling, beam lateral-torsional buckling, and reduction in the beam strength. The hysteresis curve of IPE profiles, particularly in medium and large sections, is highly declining after the buckling. In this paper, a simple method was presented to amend the efficiency of IPE beams with an arched cutting in the flange, using horizontal and vertical stiffeners of the beam web. The experimental results and those of finite element in IPE beams revealed that the simultaneous application of horizontal and vertical stiffeners of the beam web largely prevented the declining of the beam hysteresis curve and left a full effect on its behavior. Therefore, the use of these types of connections in seismic areas with high relative risks is recommended.