EXPERIMENTAL STUDY OF CONCRETE-FILLED STEEL MEMBERS WITH CIRCULAR CROSS SECTION SUBJECTED TO BENDING AND TORSION

Abstract

This paper describes an experimental study to investigate the stiffness, ultimate strength and ductility of concrete-filled steel members (composite members) with thin-walled circular cross section subjected to bending, torsion and their combinations. Torsional moment with constant distribution, bending moment with triangular distribution along the member axis, and their combinations are applied to 4 steel member specimens and 4 composite member specimens with comparatively compact circular cross section up to their ultimate state. The main conclusion is that the ultimate strength of these composite cross section can be predicted by a fully plastic interaction curve through the adoption of a practical compressive strength and shearing strength of encased concrete by considering the effect of transverse compression due to the hoop action of the outer steel tubes.