Local buckling of steel plate in axially loaded square concrete-filled steel tubular short columns

The buckling strength of square steel tubes can be notably increased by pouring the concrete. However, the steel plates may still buckle locally due to its relative large width-to-thickness ratio. The finite element software ABAQUS was employed in the buckling strength simulation of single steel plate from square concrete-filled steel tubular short column. The finite element analysis was verified with the theoretical results. In order to increase the buckling strength and the confinement provided for concrete, reinforcement stiffeners were welded into the tubes, to research on their influence on the buckling strength and out-of-plane displacement. Taking the direction and location of stiffeners as the influence parameters, parametric analysis was conducted to get the conclusions: the stiffeners can effectively improve the tube's mechanical properties and closer spacing of stiffener constraint points in loading direction plays more significant role than that in horizontal direction.