Compression tests of channels with inclined simple edge stiffeners

Abstract

The paper describes a series of tests on cold-formed channels with inclined simple edge stiffeners compressed between fixed ends. The simple edge stiffeners of the channel sections consist of simple lips. The new North American Specification and the Australian/New Zealand Standard for cold-formed steel structures provide design rules for channels with inclined edge stiffeners. However, the design rules are mainly based on tests of sections having edge stiffeners perpendicular to the flanges. The provisions for inclined edge stiffeners are determined based on intuition without rigorous experimental evidence. Hence, it is important to obtain test data for sections with edge stiffeners not perpendicular to the flanges. A series of compression tests was performed on cold-formed channels with inclined edge stiffeners. The edge stiffeners of the channels were inclined at different angles for both outwards and inwards. The distortional buckling mode, where the flange and lip rotate about the flange-web junction restrained by the web, was observed in all tests. The test strengths are compared with the design strengths predicted by the North American Specification, the American Iron and Steel Institute Specification, and the Australian/New Zealand Standard for cold-formed steel structures. For the North American Specification and the American Iron and Steel Institute Specification, the distortional buckling mode is not explicitly accounted for in design. However, the Australian/New Zealand Standard has explicit design rules for distortional buckling in addition to the edge stiffened design rules which are the same as the American Iron and Steel Institute Specification.