Experimental and Numerical Study on Bar-Reinforced Concrete Filled Steel Tubular Columns Under Axial Compression

Abstract

The behaviors of bar-reinforced concrete filled steel tubular columns subjected to axial load were studied. One plain concrete filled steel tubular column and three bar-reinforced concrete filled steel tubular columns were tested. The deformation of specimens and the strain of steel tubes were measured. Based on experimental researches, a simple numerical analysis method was presented to simulate the full load-deformation process of bar-reinforced concrete filled steel tubular short columns subjected to axial compression. Firstly, the interaction process of steel tube and concrete was analyzed, and then, the simplified constitutive models of steel tube and concrete were established on the base of previous analysis results. Secondly, the relation between lateral and longitudinal strain of steel tube was analyzed based on experimental results, and a simple method was presented to calculate the lateral strain of steel tube. This method was used as the supplement to the constitutive models. Finally, a program was worked out to simulate the full load-deformation process of bar-reinforced concrete filled steel tubular short columns. The program’s simulation results of both ultimate bearing capacity and load-deformation curves are in good agreement with the experimental results.