Nonlinear Finite Element Analysis Of Structural Behsvior Of CFST-Core Steel Tube In Corner Column Joint

At present concrete filled steel-tubular structure (CFST) has been used in many high buildings, but the CFST column connected beam or board have a lot of questions and the fist is one of key technical problems to research CFST. Therefore, the deep study on the dynamic behavior of the joints above-mentioned will contribute to promoting the structural design and engineering application. CFST column joint connected by core steel tube is a new type of column-RC beam joint. The column of CFST is disconnected in the joint Zone where the core steel tube is installed. The longitudinal steel bar of the RC beam can go through the joint zone. The new type of joint makes beam and concrete in the joint zone become one, and the moment, shear and axial compression can be carried in a good condition. The research in this article is to be continued after half-continuous CFST column corner joints research connected by core steel tube and the paper makes use of numerical analysis to redeem the defect that the number of models is small. The contents of this article are as below:First: it introduces the solutions of non linearity system of equations, the analysis of non linearity in ANSYS and the basic process of solving problems with ANSYS. These make preparations for joint models formation.Second: Based on the appropriate material constitutive equation and failure criterion, fourteen nonlinear finite element method models are set up with ANSYS.Third: Under axial load, by the numerical analysis of fourteen joint models' vertical bearing capacity, load-displacement curves and various parts' stress distribution maps, some conclusions are gained. The frame concrete beams around joint are hardly restrain joint under vertical load. So they can be ignored. The vertical bearing capacity of four joints increases with increasing core steel tube wall thickness. The vertical bearing capacity of four joints decreases with increasing diameter of core steel tube. The vertical bearing capacity of four joints increases with increasing diameter of stirrup and reinforcing steel bar, but the increasing scope is small.For sake of time, this article only makes nonlinear finite element analysis of joints under axial load. More researches on stress under other cases should be made.