Elastic-plasticity Analysis Of Concrete Filled Square Steel Tube Column

This paper presents a finite element method (FEM) model for the analysis of concrete filled square steel tube column based on ANSYS. The elastic-plasticity model is used to describe core concrete which is modified by Linghai Han and bilinear elastic-plasticity model is used to describe the steel tube. Analysing and comparing test result with numeration result of axial and parial components for concrete filled square steel tube column,We find that numeration result anastomoses test result well,which testifies the feasibility of numeration method for test.folowing this, dead- load mecanical behaior and P-A hysteretic behavior are researched.The parameters analysis indicates that confinement index eccentric ratio to eccentric column . axial compression ratio and slenderness ratio are the most significant effect factors. For the concrete filled square stell tube member, the more confinement index is, the better mechanical behavior is shown, which includes the more significant confined force, larger ultimate load, better ductility. The eccentric ratio to the eccentric columns is another important factor. It is indicated that the confined force and the ultimate load decrease with the increment of eccentric ratio, the eccentric ratio not only lows down the ultimate load, but also weakens the confined force of the steel tube in the concrete compressed area. The more the eccentric ratio is, the later the confinement of the steel tube plays role, and the less the area is, the less the confined force is. The axial load ratio influenced the columns behaviors significantly, the larger axial load ratio is, the lower ultimate load and worse ductility is shown. And the accretion of slenderness ratio weakens the carrying capacity and ductility of the component seriously.