Numerical simulation of sleeve connections for cold formed steel sigma sections

• The behaviours of the simga purlin sleeve connection are numerically simulated.
• The key parameters influencing the behaviours of the sleeve connection are studied.
• Optimal sleeve design is proposed.
• The sleeve connection behaves as a partially rigid connection.

Cold-formed steel sigma purlins provide positive structural features such as enhanced web buckling resistance and a closer shear centre to the web. In modern roof construction, the sleeve connection for sigma purlins is often favoured due to advantages such as adequate structural efficiency, ease of installation and freedom from restrictions on the length of the connected purlins. This paper presents a finite element (FE) model developed for typical sleeve connections used in the sigma purlin system. The aim of the modelling is to numerically reveal the structural behaviour of such a connection, and to provide supplementary information that is usually lacking in laboratory tests. Detailed information on input parameters required to implement the FE model, such as the choice of element type, idealisation of the connection, and loading and boundary conditions, are documented. The developed FE model was validated by 20 laboratory tests. It was then applied to carry out a parametric study. The influence of the geometric dimensions of the sleeve section (i.e. sleeve thickness and sleeve length) on the moment–rotation behaviour and the moment resistance of the sleeve connection was particularly studied. The results obtained are expected to provide useful information for academic and engineering professionals in the analysis and design of sigma purlin systems using sleeve connections.