Effect of External Ring Stiffener on the Chord Members of Cold-Formed Steel T-Joints Under Combined Axial Compression and Bending

This paper aims to study the experimental and analytical behaviour of cold-formed steel (CFS) T-joint members with or without external ring stiffeners under combined axial compression and bending. The parameters varied in the study include the type of T-joints (with and without ring stiffeners), spacing of the stiffeners (100 mm and 200 mm from the central axis of the T-Joint), and thickness of the ring stiffeners (4 mm and 6 mm). The load–deflection and load-strain behaviour were studied by measuring the overall deflection of the T-joints and strain using dial gauges and strain indicators, respectively. The load-carrying capacity of the T-joints with external ring stiffeners was compared, and the results of a numerical investigation showed good agreement. An extensive parametric study was carried out for different geometric parameters of the ring stiffener, chord, and brace member using the FE model to obtain the ultimate strength of the stiffened T-joints, and strength was also compared and obtained using the published equation. From the results of this investigation, it was found that the T-joints with external ring stiffeners can resist more strength and deformation when compared to the T-joints without external ring stiffeners.