Experimental behavior of concrete-filled stainless steel tubular columns under cyclic lateral loading

Concrete-filled stainless steel tubular (CFSST) columns have attracted increasing research interests in recent years; however, It seems that the behavior of this type of innovative column under cyclic loading has not been addressed sufficiently so far. This paper reports test results of 10 CFSST columns under constant axial load and cyclically increasing flexural loading. The main parameters varied in the experiments were axial load level, cross-sectional type, and concrete type. The influences of these parameters on strength, ductility, stiffness, and energy dissipation were investigated. It was found that CFSST columns exhibited excellent energy dissipation and ductility, even when the specimens were subjected to high axial loads. The hysteretic behavior of the tested CFSST columns was compared to that of their carbon steel composite counterparts reported in the literature. Several existing design codes were used to predict the ultimate strength and flexural stiffness of the test specimens, and some suggestions are proposed accordingly for designing CFSST columns.