3-D FEM analyses on internal state inside the concrete filled steel tubular column subjected to flexural deformation considering the composite action with and without an adhesive behavior

Abstract

The present paper deals with the 3-D finite element deformation analyses of concrete filled steel tubular (CFT) column subjected to the lateral loading as well as the constant axial loading. The adhesive behavior between steel tube and filled concrete is modeled by the interface element to investigate the composite action and the confining effect inside the CFT column. By introducing a new index, namely, the equivalent confining pressure, the local stress-strain behavior at the Gaussian point level is investigated to evaluate the confining effect quantitatively. It can be concluded from the present numerical analyses that the adhesion inside CFT column contnbutes to an increase in the load bearing capacity and also the prevention from the local buckling of steel tube at the range of 0.5D (D: the diameter of column) from the base of column.