Bending–shear interaction in short coupling steel beams with reduced beam section

• Published in: Journal of constructional steel research 2016-07, Vol.122, p.190-197
• Main Authors: Crisan, Andrei, Dubina, Dan
• Format: Article
• Language: English
• Subjects: Beam FEA; Bending moments; Cyclic loading; Finite element method; Frames; Hinges; Mathematical models; M–V interaction; Parametric study; Reduced beam section (RBS); Rotational; Shear; Steels
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2016.03.020

In current design provisions, the plastic moment and rotation capacity of plastic hinges for beams must not be decrease due to compressive and/or shear forces. For the majority of moment-resisting frames, the influence of shear and axial forces on the bending moment and rotational capacity of plastic hinges can be ignored, because the shear and axial forces typically observed are low relative to the shear and axial capacities. However, in some cases, the lateral force-resisting systems are composed of closely spaced columns rigidly connected by short steel beams. Each of these beams is long enough to allow the development of plastic moment hinges at the ends, but also short enough to develop significant shear forces that can influence the bending moment and rotational capacity of the beam. This report presents a parametric study conducted using an experimentally calibrated numerical model, performed at the CEMSIG Research Centre (http://www.ct.upt.ro/en/centre/cemsig) at the Politehnica University of Timisoara. The study observes and characterizes the plastic mechanism of short steel beams with reduced beam sections (RBS) applied in moment-resisting frames. A simplified and reliable alternative allowing the use of beam finite element analysis (FEA) for bending–shear interactions is proposed. •Based on the experimental program findings presented in the present paper, it can be said that short coupling steel beams with reduced section can dissipate seismic energy though plastic deformations if properly detailed even if the shear – moment interaction occurs•Using a calibrated finite element model, the geometric parameters that influence the behavior of short coupling beams were identified•An interaction formula was proposed to account for the shear – moment interaction for plastic design of short coupling beams•A simplified pushover analysis using beam FEA was proposed to evaluate the behavior of frames with short coupling beams