ULTIMATE STRENGTH OF COLD-FORMED STEEL BUILT-UP COLUMNS: EFFECT OF LACING SLENDERNESS
M. Adil Dar, Dipti Ranjan Sahoo*and Arvind K. Jain
Department of Civil Engineering, Indian Institute of Technology Delhi, New Delhi, India
Cold-formed steel (CFS) sections have gained popularity in the recent years primarily due to their high strength-to-weight ratio and faster constructions. Built-up members are often adopted as compression members subjected to the high axial force demands. Past studies have mainly focused on the performance evaluation of built-up CFS columns with intermediate battens. In this study, a numerical investigation has been conducted on built-up CFS column specimens comprising of four angle sections connected each other by using lacings. Finite element models are developed in a computer software ABAQUS to investigate the behaviour of built-up CFS laced columns of varying slenderness ratio and spacing of lacing elements. The numerical models are validated against the test results for built-up laced CFS columns. Finally, design curves for the built-up CFS laced columns are developed and compared with those in current design standards. This study ascertained that lacing slenderness affects the ultimate axial load-resisting capacity of built-up CFS columns.
Built-up columns; Cold-formed sections; Lacings; Numerical modelling; Strength