Shear Buckling Behaviour of Cold-Formed Steel Members With Web Openings

Abstract

Cold-formed steel (CFS) sections have become a common choice in
modern construction because they offer considerable strength while remaining lightweight and straightforward to install. When openings are cut into the web to accommodate building services, however, the way these members carry shear can change substantially. In this work, the behaviour of channel sections containing such openings is examined in detail. A series of nonlinear Finite Element (FE) simulations was created, each including the influence of initial geometric imperfections, and the numerical responses were compared with available test data to ensure they reflected physical behaviour. After validation, the models were used to study how different variables, including the shape of the opening, its size, and the slenderness of the web, affect shear resistance. The numerical results indicate a sharp drop in capacity when the openings become large or when the web is relatively thin, with the most severe cases showing reductions approaching 90% for opening size and roughly one-third for web slenderness.