Behaviour of Cold Formed Steel Rectangular Hollow Section Filled with Concrete under Cyclic Lateral Loadwith Constant High Axial Compression

This paper presents an experimental investigation of Rectangular Concrete Filled Steel Tube (RCFST) sections subjected to cyclic lateral load combined with constant high axial compression. A total of eight RCFST columns with different combinations of width to thickness ratio, slenderness ratio and axial compression ratio were tested. The constant axial compressive load on the test columns was 60% and 80% of its axial load carrying capacity. Failure modes such as local buckling and rupture of steel tube were observed from experiments during strength degradation after reaching maximum lateral load. From the experimental results, envelope curves were obtained by joining the locus of extremities of the load-displacement hysteresis loops. Seismic parameters such as strength, stiffness, ductility, and energy dissipation capacity were discussed based on experimental results.