Advanced design for trusses of steel and concrete-filled tubular sections

This paper presents an experimental and analytical investigation of buckling behavior of bare steel and concrete-filled steel (CFS) tubes used as columns and as members of trusses. The member resistances of the columns and trusses consisting of steel and CFS tubular members are compared to demonstrate the beneficial effects of the in-filled concrete, with their resistances predicted using the conventional effective length and second-order analysis methods of design in various international standards such as Eurocode 3 (EC3), Eurocode 4 (EC4), CoPHK, AISC-LRFD and AS5100. Test results are further used to validate the proposed second-order analysis, which skips the assumption of effective length, for accurate and reliable design of composite members. The present holistic approach of considering composite members as constituting elements in a truss represents a piece of original work on testing and design of structures as a system, rather than designing members in isolation in the traditional member-based design.