Web Crippling Behavior of Unlipped Cold-Formed Ferritic Stainless Steel Channels Subject to One-Flange Loadings

Abstract

The web crippling strength of unlipped cold-formed ferritic stainless steel channels subject to interior-one-flange and end-one-flange loading is considered in this paper. A total of 144 results are presented, consisting of 36 laboratory and 18 numerical results. These results cover the cases of both flanges, restrained and unrestrained to the load and reaction plates. Unlike other work in the literature, the numerical analysis in this paper uses nonlinear quasi-static finite-element analysis with an implicit integration scheme, which has advantages over static and quasi-static with an explicit integration scheme analysis, particularly for postbuckling predictions of unlipped channels subject to web crippling. The laboratory and numerical investigations show the current stainless steel design guidance to be too conservative. In terms of design standards, although no cold-formed stainless steel standard distinguishes between flanges restrained and unrestrained to the load and reaction plates, with each standard providing only one equation to cover both restrained and unrestrained, the web crippling strengths for the flanges unrestrained case were found to be higher than those predicted from the current American specification by as much as 24%. In addition, the web crippling strengths for the flanges restrained case are shown to be higher than those predicted from equations found in the literature by as much as 14%. New web crippling design equations are proposed; the proposed equations are shown to be reliable when compared against laboratory and numerical results.