BEHAVIOUR OF ELLIPTICAL CONCRETE-FILLED STEEL TUBULAR LONG COLUMNS SUBJECTED TO ECCENTRIC COMPRESSION

A finite element analysis model of elliptical concrete-filled steel tubular ( CFST) long columns subjected to eccentric compression is established using the finite element analysis software ABAQUS and the corresponding tests of 12 specimens are carried out． The results show the predicted relationship curves of load versus deflection in the middle column and damage modes are in good agreement with the measured results． The finite element analysis model is thus used to investigate the stress and strain distribution of each component and the interaction between the steel tube and the core concrete in the whole loading process． And then，the main parameters influencing the relationship curves of load versus deflection in the middle column such as slenderness ratio，material strength，steel tube wall thickness and eccentric distance are investigated． The results show the typical failure modes of these columns were the lateral overall bending at about mid-height，the slenderness ratio，the compressive strength of concrete，the steel tube wall thickness and the load eccentricity have obvious effects on their mechanical behavior，while the yield strength of steel tube has slight effect on their mechanical behavior．