Constitutive Model And Bearing Capacity Of Confined Steel Reinforced Concrete Columns With Circular Steel Tube

The most practical formulas for steel reinforced concrete column are based on the regression parameters of experimental data. However the coefficients in the expression of stress-strain do not give precise physical definitions, and the value of the coefficient isoften variational in a wide range. So the calculational results of the formulas are emanative. Avoiding to use the empirical coelfficients are in the analytic process and based on the stress-strain relation between core concrete and steel tube the ultimate bearing capacity and the deformation characteristic of the steel-encased reinforced concrete (SRC) columns are investigated in this paper.Then the reasonable stress-strain model is given for the further work of the damage analysis of steel-encased concrete and aseismatic ductility.The research conclusions of this paper are as follows:1. Adopting the steel yielding criterion method and the ultimate balance theory respectively, the ultimate stress expressions of steel-encased concrete including core confined concrete and the ultimate bearing capacity formula of the axially compressed column is put forward.2. Through the analysis of axial compressed performance of the circular steel tube SRC column using the finite element program ANSYS, the distributing features of circumferential stress, radial stress and axial stress of the SRC column are described .3. Concrete confined coefficient K by the numerical integral of whole section using strip method is put forward for the bearing capacity formula of eccentrically compressed SRC column.4. Using the numerical integral of whole section, the force-displacement relation and the flexural strength for the SRC column with circular steel tube are analyzed.