Parametric Studies and Design Recommendations of Cold-formed Steel Sections with Web Openings subjected to Web Crippling

Abstract

A parametric study of cold-formed steel sections with web openings subjected to web crippling was undertaken using finite element analysis, to investigate the effects of web holes and cross-section sizes on the web crippling strengths of channel sections subjected to web crippling under both interior-two-flange (ITF) and end-two-flange (ETF) loading conditions. In both loading conditions, the openings were located at the mid-depth of the webs. It was demonstrated that the main factors influencing the web crippling strength are the ratio of the hole depth to the flat depth of the web, the ratio of the distance of the hole from the edge of the bearing plates to the flat depth of the web and the ratio of the length of bearing plates to the flat depth of the web. In this paper, design recommendations in the form of web crippling strength reduction factors are proposed; these are shown to be conservative to both the experimental and finite element results.