Elastic shear buckling of cold-formed steel channels with edge stiffened web holes

Abstract

Cold-formed steel (CFS) beams are commonly deployed in construction with web holes to accommodate service conduits. The web holes are subjected to stiffening methods aiming to restore the load-carrying strength reduction. In the shear design of CFS channels with stiffened web holes, the elastic shear buckling strength is the basis for the design irrespective of the available post-buckling strength. Therefore, this paper investigates the elastic shear buckling characteristics of CFS channels with stiffened circular web holes, which is still unresearched. Numerical simulations were conducted using the Abaqus finite element analysis software to study the elastic shear buckling response. Parametric studies were then performed, where a data pool was generated for CFS channels with no web holes, unstiffened web holes, and stiffened web holes, covering a range of parameters including web slenderness, web hole size, corner radius and edge stiffening element length. It was shown that edge stiffening of the web hole improves the shear buckling capacity compared to the CFS channels with no web holes and unstiffened web holes. New unified design proposals to estimate the elastic shear buckling strength of CFS channels with no web holes, unstiffened web holes, and edge stiffened web holes were developed based on the generated data. The new unified design proposals of modified shear buckling coefficient and equivalent thickness method offer accurate elastic shear buckling strength predictions.