Transverse Stiffener Requirements for Shear Postbuckling of Cold-Formed Steel Channels

Abstract

The enhanced shear strength of transversely stiffened shear panels compared to the strengths of the unstiffened has been well recognized in the Specification for Structural Steel Buildings (AISC 360) and the North American Specification for the Design of Cold-Formed Steel Structural Members (AISI S100). The requirements for the transverse stiffeners to secure such strength enhancement was similar in early versions of the two specifications, but the Specification for Structural Steel Buildings has recently adopted a whole new approach to reflect more closely the actual mechanistic behavior of stiffeners in the context of steel plate girders. The paper presents a series of shear tests on cold-formed steel beams with various transverse stiffener sizes followed by finite-element nonlinear collapse simulation to demonstrate the applicability of transverse stiffeners in the context of cold-formed steel members. The experimental series consists of six tests on 200-mm-deep C-shaped sections having angle intermediate transverse stiffeners screw-fastened to the web also reveals the conservatism of the transverse stiffener design rules in the AISI S100-16 specification. Based upon the experimental and numerical results, the paper recommends the adoption of the corresponding provisions taken from the AISC 360-16 specification.