Influence of load conditions on mechanical behavior of CFST stub columns subjected to axial compression

Based on the theoretical model, material parameters and analytical results are confirmed by the experiment data, a finite element program DIANA is employed to analyze the mechanical behaviors of concrete-filled steel tube (CFST) stub columns under three types of loading conditions: 1. Steel tube and concrete subject to compressive load simultaneously; 2. Compressive load acts on concrete only with no bond between steel tube and concrete; 3. Compressive load acts on concrete only with full bond between steel tube and concrete. Results show that if the steel tube and concrete are loaded simultaneously, the bond strength has no influence on the behavior of the stub columns, while if the load is acted only on concrete, the mechanical behavior of the stub columns are greatly influenced by the bonding conditions between steel and concrete.