A Theoretical Study On Mechanical Properties Of Double Component Concrete Filled Steel Tubular Column

With the development of modern life and the improvement of living quality, people’s requirements for the layout and comfort of the living environment have been growing. Special-shaped column construction satisfies needs for proper utilization of housing space, makes it easier to arrange furniture, and provides better lighting. Generally speaking, cross-section forms of special-shaped column consist of cross-shaped section, Z-shaped section, T-shaped section, L-shaped section, semi-circular section,1/4 circular section, ellipse section, octagon section and so on. On this basis, double component concrete filled steel tubular (DC-CFST) column is proposed in this paper.This paper conducts following studies on DC-CFST column:Using the material model in ABAQUS and selecting proper constitutive relationship of material, make finite element analysis on DC-CFST column at the angle of 90°. The results and the test data were extracted to conduct contrast analysis. The results showed that both were well matched with each other. In order to explore the angle influence on DC-CFST column, some test specimens were set up at the angle of 90°,105°,120°,135°,150° and 180°. Experimental results showed that the axial compression bearing capacity of the DC-CFST column specimens barely increases as the angle increases. The influence factors of constraint between steel tube and concrete core include angle, length-width ratio D/B, width-thickness ratio B/t, and the steel ratio. The constraint effects between materials of DC-CFST column reach the best point, when the D/B is about 2.25. And it is still satisfactory when D/B is in the range of 2-2.75.The calculation results of CFST columns in the GJB discipline, DBJ discipline, ACI/AIJ discipline, EC4 discipline and CECS discipline were contrast with the ABAQUS simulation results. The comparative analysis indicate that the calculations in the GJB discipline, DBJ discipline, ACI/AIJ discipline and EC4 discipline differ greatly from the finite element simulation results, but that of CECS discipline is similar to the finite element. The mechanical models of DC-CFST column are established by using ABAQUS under one-way and biaxial eccentric compression respectively. The mechanical properties of specimens were analyzed on that condition, and their failure mechanism and features, and their deformation properties. It is believed that research on DC-CFST column in this paper can be of use for engineering applications.