Buckling of Slender Concrete-Filled Steel Tubes with Compliant Interfaces

Abstract

This paper presents an exact model for studying the global buckling of concrete-filled steel tubular (CFST) columns with compliant interfaces between the concrete core and steel tube. This model is then used to evaluate exact critical buckling loads and modes of CFST columns. The results prove that interface compliance can considerably reduce the critical buckling loads of CFST columns. A good agreement between analytical and experimental buckling loads is obtained if at least one among longitudinal and radial interfacial stiffnesses is high. The parametric study reveals that buckling loads of CFST columns are very much affected by the interfacial stiffness and boundary conditions.

Evaluation of limit state of stress and strain of free-fixed columns with variable geometry according to criteria from the Brazilian code for concrete structures

“…It is worth mentioning that, although the average wall thickness of the cross-sections represents 0.72% of the height of the superstructure, no analyses regarding the local buckling or distortion of the section were considered, since it is a problem that should be treated with another specific approach, as discussed by Pierin and Silva (2015). Therefore, the present approximation is restricted to the global instability evaluation, similar to the work developed by Schnabl and Planinc (2017). The moduli of elasticity of concrete at 28 days for the superstructure and foundation, solved with Equation (34)…”

Damage evaluation and failure mechanism analysis of steel tube confined reinforced-concrete columns by acoustic emission technology

“…Steel/concrete composite structure has been widely applied in high-rise buildings, long-span bridges and underground structures. Therein, concrete-filled steel tube (CFST) columns is one of the preferred components of these large-scale projects because of high bearing capacity, good seismic performance and excellent ductility (Sakino et al, 2004;Schnabl and Planinc, 2017). However, some researchers (Ding et al, 2011) reported that the confinement effect does not occur during the elastic stage when Poisson's ratio of steel is higher than that of core concrete.…”