Fiber-based computational modeling of rectangular double-skin concrete-filled steel tubular short columns including local buckling

摘要

Both the external and internal thin-walled steel sections of a rectangular double-skin concrete-filled steel tubular (RDCFST) short column loaded axially may be susceptible to progressive local buckling, which is rarely included in mathematical modeling programs employing the fiber discretization scheme for such composite members. This paper provides a description of a new computational simulation technology, which is developed for the nonlinear fiber analysis of short RDCFST columns axially loaded to failure. The progressive localized-buckling failure of thin-walled steel sections are included in the formulation of the computational simulation method. Experimental measurements and finite element analysis results obtained by ABAQUS software by other researchers are employed to evaluate the accuracy of the computer algorithms developed. Numerical studies are undertaken to ascertain the responses of RDCFST columns to the change of design parameters. Proposed is a mathematical expression for the determination of the axial resistances of RDCFST columns considering the post-localized buckling strength of thin-walled steel sections. It is demonstrated that the proposed computational modeling and design technologies yield good predictions of the responses of RDCFST columns and can be used to undertake the nonlinear simulation of RDCFST columns with any class of steel sections.