Parametric studies and design recommendations of cold-formed steel sections with edge-stiffened circular holes subjected to web crippling

A parametric study of cold-formed steel sections with edge-stiffened circular holes subjected to web crippling under one-flange loading condition was undertaken using finite element analysis.  The effect of different hole sizes, edge-stiffener length and distances of the web holes to the near edge of the bearing plate on the web crippling strengths of channel sections were investigated. The web crippling strengths are influenced by various geometry parameters: the ratio of the hole depth to the flat portion of the web, a/h, the location of the hole as defined by the distance of the hole from the edge of the bearing divided by the flat portion of the web, x/h and the ratio of the edge-stiffener length to the flat portion of the web, q/h. In order to find the effect of a/h, x/h and q/h ratios on web crippling strength of channel sections with web holes, three separate parametric studies were carried out. The results indicate that with a suitable edge-stiffener length, the web crippling strength of cold-formed steel channel section with holes can be as high as the one without holes.  In this paper, based on the finite element results a correlation are established for the web crippling strength of the channel sections without web holes, with unstiffened and edge-stiffened circular web holes corresponding with the ratios a/h, x/h and q/h for the interior-one-flange (IOF) and end-one-flange (EOF) loading conditions, respectively.