Numerical analysis of circular concrete-filled steel tubular slender beam-columns with preload affects
This paper presents a new numerical model for the nonlinear analysis of circular concrete-¯lled steel tubular (CFST) slender beam-columns with preload e®ects, in which the initial geometric imperfections, de°ections caused by preloads, concrete con¯nement and second order e®ects are incorporated. Computational algorithms are developed to solve the nonlinear equilibrium equations. Comparative studies are undertaken to validate the accuracy of computational algorithms developed. Also included is a parametric study for examining the e®ects of the preloads, column slenderness, diameter-to-thickness ratio, loading eccentricity, steel yield stress and concrete con¯nement on the behavior of circular CFST slender beam-columns under eccentric loadings. The numerical model is demonstrated to be capable of predicting accurately the behavior of circular CFST slender beam-columns with preloads. The preloads on the steel tubes can a®ect signi¯cantly the behavior of CFST slender beam-columns and must be taken into account in the design.