Finite element analysis for axial compressive behavior of CFT columns assembled with rectangular wave-shaped ribs

Abstract

This is an analytical study on the axial compression behavior of newly developed Concrete-Filled Steel Tube (CFT) columns assembled with rectangular wave-shaped ribs for thin-walled design. Based on previous experimental results, a Finite Element (FE) method suited for CFT columns was developed. Next, the stress distribution and principal stress of concrete were analyzed, as were the stress distribution and local buckling of steel tubes. Based on the results, a parameter study was conducted and used as basic data for the design model. This CFT column effectively suppresses local buckling compared to conventional CFT columns, ultimately improving the concrete confinement effect. Additionally, the compressive strength of concrete increased due to the improved confinement effect, which differed depending on the rib aspect ratio. Thus, a design model incorporating the rib aspect ratio as an independent variable was proposed. The model was validated through comparison between the experimental results and FE model data and was found to accurately predict the behavior.