Experimental and analytical studies of cold-formed steel sections with edge-stiffened circular holes subjected to web crippling

Cold-formedsteel sections are often used as wall studs or floor joists and such sectionsoften include web holes for ease of installation of services. The holes arenormally punched or bored and are unstiffened; when the holes are near topoints of concentrated load, web crippling can be the critical designconsideration. Recently, a new generation of cold-formed steel channel sectionswith edge-stiffened circular holes has been developed. The web holes arestiffened through a continuous edge stiffener/lip around the perimeter of thehole. In this paper, a combination of experimental investigations andnon-linear finite element analyses are used to investigate the effect of suchedge-stiffened holes under the interior-one-flange (IOF) and end-one-flange (EOF)loading conditions; for comparison, sections without holes and with unstiffenedholes are also be considered. A non-linear finite element models are described,and the results compared against the laboratory test results; a good agreementwas obtained in terms of both strength and failure modes.