Analysis of Behavior of Concrete-filled T-shaped Steel Tube Tall Column Subjected to Uniaxial Eccentric Load

In this paper,based on the equivalent uniaxial stress-strain relationship for concrete-filled T-shaped steel tube(CFTST)columns without stiffening measures,a fiber element model computing program was proposed for investigating the behavior of concrete-filled T-shaped steel tube slender columns,and the effects of different parameters on the behavior of CFTST columns under uniaxial eccentric load were investigated.The parameters in the analysis included the compressive strength of concrete,the yield strength of steel,the depth to thickness ratio of steel plate,the cross sectional depth to width ratio,the angle of the load,the slenderness ratio,and the axial load ratio.The results of theoretical analysis indicated that the normalized interaction curve of axial load versus bending moment was obviously influenced by the load ratio carried by core concrete,the load angle and the slenderness ratio. Based on the parametric analysis and regression analysis of a good many of numerical results,the simplified calculation methods were proposed to predict the load-carrying capacities of CFTST columns under uniaxial eccentric load.Good agreements between the values predicted by the simplified calculation methods,the fiber element model computing program and the experimental results were achieved,and the simplified calculation methods can be referred for practical engineering design.