| It had been believed that rigid beam-column connections can insure the lateral stiffness and seismic performance of the structure in the past decades.Brittle failure of the rigid connection of the structure in the 1994 USA Northridge Earthquake and the 1995 Japan Hyogoken-Nanbu Earthquakes arouse academic and engineering circles' reflection,and the research turns to a new-style Semi-rigid beam-to-column Connections.The semi-rigid connections is formed by high strength bolts and connecting components,for example angle steel,end-plate and T type steel.In this research,connections is jointed by reverse Channel,end-plate and high strength bolts,protected and strengthened by knee-bracing on the connections.The theoretical analysis of ABAQUS and experimental research of the semi-rigid connections is carried out in this paper.The main work is as follows:(1)A classification and summary is performed on concrete filled steel tube(CFST)joint after referring large number of published articles domestic and abroad.Reviewing is carried out on all available papers researching on channel connections and knee bracing,and expounding the meanings of this studies.(2)In this paper,the pseudo-static tests on seven beam-column connections and one connections with knee bracing,have been carried out.It studies on parameters such as the types(hot-rolling and cold bending)and dimensions of channels,welding methods between beam and column,concrete existing or not in the column,setting or not setting knee bracing,discusses the mechanical property of connections such as failure characteristics,bearing capacity,stiffness,stress and strain relationship.The result shows that the beam-column connections with channel have a high rotation stiffness and high bearing capacity,in addition,the stiffness and energy-dissipating capacity of structure can get remarkably enhanced with knee bracing.(3)Based on the experience of the connections,numerical simulation was carried out using finite element software ABAQUS.There are small difference between finite element calculation results and related test results.Advanced research is performed on the type of connections which can impact the performance,including the configuration and attenuation of knee bracing,after taking other factors into consideration.Through the result of the research,it shows that the connection performance of the channel joint is robust,which makes it easy to connect the beam and the column.stiffness and energy-dissipating of structure get enhanced with knee bracing,which is adaptable to some structures with special requirements of stiffness. |
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