The effects of axial tension on the sagging-moment regions of concrete-filled tubular flange girders

Abstract

Steel-concrete composite construction is commonly used for many types of structure, including heavy load-bearing applications such as bridges and multi-storey car parks. Some of their component elements such as bridge approaches, inclined parking ramps and stadium beams are exposed to a simultaneous combination of high axial loads and bending moments. A relatively new solution for heavily loaded composite members are concrete-filled tubular flange girders (CFTFGs) which are unconventional I-shaped girders where one or both of the steel flanges are replaced with a hollow section and then filled with concrete to increase the strength and stiffness. These are complex members and their behaviour is governed by a number of inter-related parameters. This work aims to investigate the ultimate strength of CFTFGs with a stiffened web under the combined effects of various levels of axial tension and positive (sagging) bending moment. Nonlinear three-dimensional finite element (FE) analyses using the ABAQUS computer software package are employed to conduct parametric studies. Several influential parameters are examined and conclusions are discussed.