Web crippling strength of thin-walled steel members with web opening

This paper is concerned with the effect of web openings on the web crippling strength of unreinforced cold-formed (thin-walled) steel members. The influence of an opening has been examined through experimental research on C-shaped lipped channel sections subjected to interior one flange loading condition. First, the web crippling provisions of various Canadian design codes have been reviewed. Then, the results of the 103 laboratory tests undertaken by the authors are presented along with the description of test procedure. The parameters covered in this investigation include web height to thickness ratio, opening height/web height and opening width/bearing length. Experimental data corresponding to sections without opening have been compared to code estimations. Based on the non-linear regression analysis of the test results a prediction equation for the influence of an opening has been established. Until further results become available, the prediction equation proposed herein may be used in the web-crippling design of thin-walled steel members with web openings.