Research on the Bearing Capacity of Concrete Filled Circular Steel Tubular Columns under Concentric Loading

• 1、Central South University

Abstract：This paper presents a formula of the stability bearing capacity for the concrete filled circular steel tubular (CFST) columns under concentric loading. Firstly, based on the fiber model method, the load-deformation curves of CFST columns under concentric loading were simulated. And the numerical calculation method of the bearing capacity of the columns was developed. Secondly, in terms of the tangent modulus method, the calculation formulas of stability bearing capacity were proposed. The calculated results of fiber model method were in safe range when compared with tangent modulus method. Finally, applying fiber model method, the influences of the significant parameters, such as slenderness ratio, strength grade of concrete, yield strength of steel and steel ratio on stable coefficients of the columns were discussed and a formula of the stability bearing capacity for the columns was suggested through modifying the formulas from tangent modulus method. And the reliability of the method was tested by 216 specimens at home and abroad.

Keywords： concrete filled tubular steel columns, slenderness ratio, stable coefficients, bearing capacity