Paper Title
Interaction Curves for Concrete Filled Square Steel Tube Columns Under Axial Compression and uniaxial Bending

Abstract
The Eurocode 4 simplified method for design of composite columns was adopted in the present work to developed the axial compression – uniaxial bending interaction curves for twelve different sections of concrete filled square steel tube columns, which are the most common used in constructions. Different material properties were considered in these interaction curves to cover a large range of options for use in practical situations. The effect of steel reinforcement was neglected for all cases that considered and therefore the constructed interaction curves are on the safe side. It was observed that the CFST column section resistance for compression can be increased significantly with the increase of concrete strength, whereas, the increase of the steel strength developed overall increase in the resistance of the CFST column sections to the applied combination of axial compression and uniaxial bending. Keywords - CFST, Interaction Curves, Eurocode4, Composite Columns.v