Experimental study on the mechanical behavior of eccentrically loaded steel tubular columns filled with structural steel and concrete

Considered strength classes of concrete,ratio of structural steel to concrete,ratio of steel tube to concrete and eccentricity ratio of load,6 test specimens of steel tubular columns filled with structural and concrete are designed.The damage phenomena of specimens are described in detail and the failure mechanism is analyzed.The results show the initial failure of the specimens are began from the yield of steel tube,the ultimate failure are ended from the buckling of steel tube caused by the expansion of core concrete.Due to the existence of structural steel,the ductility of specimens is superior to steel tubular columns.Before the yield of steel tube,the plane cross-section assumption of specimens can be put into use.The ultimate bearing capacity of specimens is increased with the increase of strength classes of concrete,ratio of structural steel to concrete and ratio of steel tube to concrete.But the ultimate bearing capacity and ductility are decreased with the increase of eccentricity ratio.