MECHANICAL BEHAVIOR AND PARAMETRIC STUDY OF CONCRETE-FILLED STEEL TUBULAR STUB COLUMNS WITH ENCASED PROFILED STEEL UNDER AXAIL COMPRESSION

The encased profiled steel can significantly improve the bear-capacity and ductility of concrete-filled steel tubular (CFST) members. This paper presents a finite element model (FEM) to investigate the axial compressive mechanical behavior of a square CFST stub column with internal profiled steel using ABAQUS based on reasonable constitutive models of steel and core concrete. The numerical results were verified and matched well with the other researchers’ experimental results. Based on the model, the load distribution of different components of the column were calculated and analyzed. Parametric analysis was performed based on the typical practical factors. The results show that the ultimate strength of this type of CFST columns will be enhanced effectively due to the incremental strength of steel and concrete, the strength of profile steel, the steel ratios of steel tube and internal steel, respectively. The results are referred to further research on the mechanical behavior and strength index of the new type of composite column.