BEHAVIOUR OF SPECIAL-SHAPED STEEL TUBULAR STUB COLUMNS UNDER AXIAL COMPRESSION

Finite element analysis ( FEA) models for 5 kinds of special-shaped ( triangular section，fan-shaped section，D-shaped section，1 /4 circular section，semicircular section) steel tubular stub columns with the same perimeter of cross-section under axial compression are developed using the finite element analysis software ABAQUS and the corresponding tests are conducted for comparison． The predicted load versus strain relationship curves and failure modes are in good agreement with the measured results． The FEA models are then used to analyze the stress and plastic strain distribution of the steel tube during the whole loading process． And finally，the main parameters influencing the bearing capacity and deformation such as section form，steel tube wall thickness and steel tube yield strength are investigated． The results show the typical failure modes of these stub columns were the local buckling at about mid-height，the section shape，the steel tube wall thickness and the steel tube yield strength have obvious effects on their mechanical behavior．