Parametric study on the structural behaviour of steel plates in concrete-filled fabricated thin-walled box columns

Abstract

A theoretical investigation of the post-local buckling behaviour and ultimate strength of steel plates in concrete-filled fabricated box columns is presented. The finite element method is used to predict the post-local buckling response of plates restrained by concrete. Geometric imperfections and residual stresses are considered in the analysis. The model developed is initially compared with a classical solution for clamped plates with initial imperfections. An extensive parametric study is then carried out to investigate the minimum local buckling coefficient and the effects of geometric imperfections and residual stresses on the post-local buckling strength of clamped steel plates. An effective width model is proposed for the design of clamped steel plates, and this can be used in the determination of the ultimate strength of short concrete-filled box columns. Independent test results of concrete-filled steel box columns are compared with the theoretical predictions by using the proposed design model. It is confirmed that the proposed design formulas predict the behaviour of real concrete-filled steel box columns extremely well.