The Research On The Behavior Of End-plate Connect Semi-rigid Composite Joints Of Steel Frame

With the extensive application of composite structures, the behavior of composite actionbetween concrete floor and steel beams has become an attractive area for research. Consideringthis kind of combination function, the frame should be designed according to steel-concretecomposite frames, and the working behavior of its beam-column connections is the basis ofanalytic foundation of such frames. A high degree of continuity can be achieved just providingthe slab with rebar running along the column. Furthermore, stiffness and ultimate resistancecan be controlled in a rather simple way by a suitable selection of steel connection detailingand amount of reinforcement. But at present, the knowledge of joint behavior, and of itsinfluence on frame behavior, is not broad enough to allow for joint design and detailing at therequired degree of reliability. Thus it is necessary to study moment resistance, rotationstiffness , rotation capacity of the joints and the effect of such joints on the behaviour of thecomposite frames.In this paper, end-plate connection semi-rigid composite joints are analyzed to obtainmechanical behaviour under static loads and the effect of such joints on the behaviour of thecomposite frames because they are widely applied in engineer. The component methodintroduced in Eurocode3 are adopted mainly to analyse the behaviour of the joints. Thebending bearing capacity and initial stiffness of connections are obtained by calculating andanalysing each component of joint. The calculating result is compared with that of experimentand finite element software ANSYS, and the comparison result indicates a good agreement.Changing the parameter of each component, the effects of each parameter of joint on thebending bearing capacity and initial rotational stiffness of connections are analysed. Thecalculating results show that the composite action between concrete floor and steel beamsgreatly influence the bending bearing capacity and initial rotational stiffness of joints, it shouldbe considered in practical engineer. Reinforcement ratio of lengthways reinforcing bar andthe stiffener of web have great influencer on the behavior of connections, while the thicknessof end-plate and degree of shear connection have a litter influence on its behavior. Based onthe analysis of the behavior of joints, further analysis about the composite steel frame isproceeded. In this way, the stiffness matrix of the frames is inferred, and the formula of thefixed moment calculation about beam element with semi-rigid connections is presented. At theend of this paper, a two-span and five-story composite steel frame is analyzed using finiteelement software ANSYS8.0.The analysis indicates that the semi-rigid behaviour of joints havesome influence on the mechanical behavior of frame, but the main factor of influence is the...