Investigation of sectional capacities of cold-formed perforated steel channel sections

Web holes are commonly seen in cold-formed steel channel sections to accommodate the technical services. The presence of the web holes has resulted in the reduction of the sectional capacities of the cold-formed steel sections and has been considered in the design according to the American Specification AISI S100-16 using a new approach in the design called the Direct Strength Method (DSM). This article, therefore, will use this design method to investigate the sectional capacities of perforated channel sections under compression or bending with the variation of hole sizes in relation to those of gross channel sections. Elastic buckling analysis - a compulsory requirement for application of the DSM - can be conducted using a module CUFSM software program recently developed by the American Iron and Steel Institute. The investigated channel sections are taken from the availably commercial sections. The obtained sectional capacities are seen as the opposite trends for local and distortional buckling modes, although a downtrend of the sectional capacities is found in general with the increase of hole dimensions. It was found that perforated channel sections with smaller hole height and longer hole lengths were recommended to obtain the optimum section capacities in terms of the same web hole area, but the opposite trend was seen for these sections under bending with long hole lengths.