Tests on curved concrete filled steel tubular members subjected to axial compression

This paper describes a series of tests on curved concrete filled steel tubular (CCFST) members subjected to axial compression. Eighteen specimens were tested to investigate the influence of variations in the tube shape (circular and square), initial deflection (0–30 mm), and slenderness ratio (20 and 60) on the performance of the curved composite members. The behaviour and failure modes of the CCFST were investigated and compared with those of conventional eccentrically loaded concrete filled steel tubular (CFST) columns without initial deflections. A finite element model (FEM) was developed to perform an analysis on the full-range load versus deformation curves of CCFST members under axial compression. Comparisons were made between the experimental results and the predicted load-carrying capacity using existing design codes, such as AIJ-2008, AISC-2005, BS5400-2005, DBJ/T 13-51-2010 and EC4-2005.

Research highlights
► Tests on curved concrete filled steel tubular (CCFST) members.
► Finite element model (FEM) for mechanism analysis.
► Comparison between concentrically loaded CCFST and eccentrically loaded straight CFST.
► Member capacity prediction.