Numerical Behaviour Of Composite K-Joints Subjected To Combined Loading And Corrosive Environment

Concrete filled steel tubular (CFST) truss structures have been adopted in various infrastructures worldwide for the past several decades. Application of CFST truss is sometimes more prevalent in areas where harsh marine environment with chloride corrosion limits the design life of the structures. Design of connections is one of the most complicated issues in CFST truss structures, which becomes even more critical when corrosion induces section loss in the outer steel tube. Improved design in terms of economy and durability needs to be suggested based on rational research on typical composite connections in corrosive environment, whilst such research is yet limited to date. This paper thus attempts to study the behaviour of circular CFST K-joints under the combined effects of long-term loading and corrosion. A finite element analysis (FEA) model is presented and verified against existing test results. The model is then utilized to perform mechanism analysis of CFST K-joints under various loading and corrosion situations. Failure modes, detailed propagation of yield and stress distribution between materials are investigated. Finally, a full range analysis of the load-deformation characteristics is carried out for various corrosion situations, with the corresponding joint strength and ductility predicted.