Analytical behaviour of tapered CFDST stub columns under axially partial compression

This paper conducts a numerical investigation on the behaviour of tapered concrete-filled double skin steel tubular (CFDST) stub columns subjected to axially partial compression. A finite element analysis (FEA) model is developed to investigate the partial compressive behaviour of the CFDST column. The full-range load versus deformation relations of tapered CFDST columns under partial and overall compression are both analyzed using the verified FEA model. A parametric study is then conducted to investigate the ultimate strength of the column with various geometric and material parameters. Finally, a simplified model is proposed based on the parametric analysis, which could predict the ultimate strength under partial compression with generally good accuracy.