Behavior of circular tubed steel-reinforced-concrete slender columns under eccentric compression

Abstract This paper presents experimental and analytical studies on the structural behavior of circular tubed steel-reinforced-concrete columns subjected to eccentric compression. The specimens were tested to investigate the effects of load eccentricity, diameter-to-thickness ratio of steel tube, and use of shear connector studs on steel sections. The test results indicated that all specimens showed flexurally dominated failure, and the tube confinement decreased with the increasing slenderness of the columns. A nonlinear finite element model was developed using ABAQUS, in which the initial geometric imperfections and the slenderness effects on tube confinement were taken into account. A modified plastic stress distribution method was proposed to predict the resistance of the critical section of the column. Finally, an equation to estimate the effective stiffness of the column was proposed.