Mechanism analysis on concrete-filled round-end steel tubular stub columns under axial load

The analysis on concrete- filled round- end steel tubular( CFREST) stub column under axial compression were carried out using finite element software ABAQUS. The analysis results indicate that: the confinement effect provided by the round- end steel tube is between those provided by circular and rectangular steel tubes. The confinement effect provided by the round- end steel tube on the core concrete is mainly distributed in arc segment. The strength,peak strain and ductility of the CFREST column are between those of the CFST column with circular and rectangular cross- sections.For CFREST columns,the strength and ductility increase with the increasing of the steel strength,steel ratio,stiffener thickness and the number of stiffeners. As the concrete strength increases,the strength increases but the ductility drops.