Study of Strength and Behaviour of Concrete Filled Double Skin Tubular Square Columns under Axial Compressive Loads

Abstract

This paper investigates the strength and behaviour of concrete filled double skin tubular (CFDST) square columns with external stainless steel tubes under axial compression. The square CFDST column with inner circular tube is chosen. The lean duplex stainless steel material is chosen for outer steel tube. The square tube is chosen because it involves easy fabrication of beam column joints. The finite element analysis of the CFDST square column is conducted to validate the finite element model with existing experimental data. A further analysis is carried out by varying the dimensions of inner and outer tubes. The effect of various parameters on the strength and behaviour of the CFDST columns is studied. The results obtained from the finite element investigation are compared with the strength values predicted using existing formulations in the analytical investigation. A good correlation was found between the numerical investigation results and values obtained from existing formulations in the analytical investigation.