The effects of web opening on web crippling strength of cold-formed steel channels under interior-two-flange loading condition

Cold-formed steel sections are increasingly used in residential and commercial construction as both the primary as well as the secondary framing members. Web crippling at points of concentrated load or reaction is well known to be a significant problem, particularly in thin walled beams. To improve the buildability of buildings composed of cold-formed steel channel-sections, openings in the web are often required, for ease of installation of electrical or plumbing services. In this paper, a combination of experimental tests and non-linear elasto-plastic finite element analyses are used to investigate the effect of such holes on web crippling under the interior-two-flange (ITF) loading condition. In the case of the tests with web openings, the web holes located at the mid-depth of the webs. A non-linear elasto-plastic finite element model is described, and the results compared against the laboratory test results; a good agreement was obtained in terms of both strength and failure modes.