Research on Mechanical Properties of Angle Beam-column Joint with Gusset plate

There is wide use of beam-column joint with gusset plate angle connection in engineering, however, the mechanical properties of these joints are still lack of complete theoretical and experimental research. This kind of joint is often simplified as an articulated connection or other types of connections in the design. In this paper, experimental study and finite element analysis are carried out to study the flexural behavior of the beam-column joint with gusset plate angle connection. The finite element analysis is used to analyze the differences between the beam-column joint with gusset plate and other joints. The moments-rotation curves and failure modes of the three kinds of beam-column joints were obtained by the static test which were carried out. A more reasonable design of beam-column joint with angle plate of gusset plate is put forward through the research of this paper: the deformation of the column flange is restricted after adding the stiffener, which can avoid the premature yield of the column flange and making the joint have good energy dissipation capacity.

Experimental and numerical investigation of stiffened angle connection in a minor axis

The bolted angle connections which are simple, fast, cost-effective, high quality, and no site welding have been recognized as their excellent performance. The moment-rotation behavior of both major and minor axis should be both taken into considering, however, the lack of research on minor axis limits the more comprehensive application. Five monotonic tests were carried out to investigate the influence under different parameters, and a new type connection were considered and detailed. Refined finite element models were built to validate the experimental results and to do several parametric analyses on initial rotational stiffness and plastic moment resistance, including of a presence of stiffened seat angle, angle thickness, and prying force. Furthermore, a new simplified plate method was proposed for calculating stiffness of stiffened angle and web in bending. The stiffened angle gives a significant increase at the moment-resisting capacity and the initial stiffness, the ultimate rotation of all tested specimens was beyond 0.067rad. The initial stiffness and plastic moment resistance of the joints were also controlled by the column web. The presence of the stiffener in the compression zone has the none effect on initial stiffness. The numerical analysis has captured the failure reason for weld and more attention should be paid to welding of stiffener in engineering design and practice. Adding stiffener at the top-and-seat angle joint can reduce the prying force of bolt, but it still cannot be ignored. The theoretical results were in good agreement with the experimental data and finite element results; therefore, it can be used to guide the design and selection of joints.

Mechanical Properties Prediction for Cold-formed Steel Angle Connection with Various Flange Cleat Thickness

Connection is an important element in structural steelwork construction. Eurocode does not provide adequate design information for mechanical properties prediction of top-seat flange cleat connection, especially for thin-walled cold-formed steel structures. Adopting hot-rolled design with neglecting thin-walled behaviour could lead to unsafe or uneconomic design. This research aims to provide accurate mechanical properties prediction for bolted top-seat flange cleat connection in cold-formed steel structures. The scope of work focuses on the effect of various thickness of the flange cleat to the rotational stiffness and strength behaviour of a beam-to-column connection. Experimentally verified and validated finite element modelling technique is applied in the parametric investigation. Two categories of flange cleat thickness, ranged from 2 mm to 40 mm are studied. From the developed numerical models, it is observed that Eurocode has overestimated the initial rotational stiffness prediction, calculated with component method. The over-estimation would influence the overall stiffness of structures and force distribution within the components. As a conclusion, a set of newly proposed accurate predictions for initial rotational stiffness and strength of cold-formed steel top-seat flange cleat connection, with the influence of the thickness of flange cleat is presented.