The Seismic Analysis Of Concrete-filled Steel Tubular Column To Beam Joints

The concrete-filled steel tubular has the special properties such as high strength good ductility better seismic behavior and convenient construction. Study on the seismic performance of concrete-filled steel tubular column to beam joints has the inportant theoretical significance and huge engineering values and also helps to understand the mechanic behavior and configuration of the joints to promote the application of this kind of composite structures in seismic area of china.Based on the investigation of research and application of concrete-filled tubular column to beam joins in China and abroad according to engineering practice, four specimens that the joints composed by concrete filled tubular column and I-shape steel beam divided as two groups have been tested under cyclic-loading in this paper. The influences between force and displacement degradations of strength and stiffness ductility of these four joints under different axial compression ratios were presented. According to the analysis of theory, the load-carrying capacity formulation for joint core zero is also given by the united theory, it can express the change for axial compression ratio of column, this formulation is much better, simple and safety, so they can provide the reference to the engineering design.Finally use the Nonlinear Finite Element model analysis the capacity behavior of joints. The result can show the stress distribution in the joints. And then the factors of the influences of joints capacity behavior can be analyzed by changing axial compress force ratio. The results show that a good agreement between the design and analytical result, that it meets the seismic design principle and that confirms the rationality and feasibility of the new method.