An Investigation on the Cyclic Behavior of I-Shaped Beam to Circular Column Moment Connections with Channel Link

The I-shaped beam to circular column connections can be constructed by curved cutting of the beam flanges or by installing external diaphragms around the column, which cause both economic and practical difficulties. A practical method proposed for construction of these connections consists of welding a link channel to the circular column and welding the beam to the link channel. As this method is new, the effect of link channel dimensions, I-shaped beam section dimensions, circular column dimensions and the link channel stiffeners on the connection behavior is not known well. Accordingly, this paper presents a FE investigation on the cyclic behavior of I-shaped beam to circular column moment connections with link channel. The main novelty of the research is the parametric evaluation of the affecting parameters, considering the stiffness and strength degradation from ultra-low-cycle fatigue, which is made possible by including ductile damage for metallic materials in ABAQUS software. For this purpose, first, the parameters of the damage model are calibrated by comparing the numerical results with the laboratory data, and then, the connection models are analyzed under a displacement-control quasi-static cyclic loading. Based on the results, the thickness of the link channel plate has the most significant effect on the overall behavior of the connection compared to other link parameters. It is also observed that the link channel stiffeners increase overall stiffness and strength of the connection. However, they cause extension of yielding towards the beam to link connection, and cause rapid growth of plastic strain in this area.