Web Crippling of Cold-Formed Stainless Steel Tubular Sections

Abstract

Experimental and theoretical investigations on cold-formed stainless steel tubular sections subjected to web crippling performed by the authors are summarized in this paper. The web crippling test results of cold-formed stainless steel tubular sections subjected to four loading conditions specified in the American and the Australian/New Zealand specifications are presented in this paper. Moreover, web crippling tests conducted under end and interior loading conditions to simulate a floor joist member seated on a solid foundation subjected to a concentrated load are also reported, and these loading conditions are not currently specified in the specifications. All of these test results are compared with the design strengths obtained using the American, the Australian/New Zealand and the European specifications for cold-formed stainless steel members as well as the North American specification for cold-formed carbon steel structural members. It is shown that the design strengths predicted by these specifications are either unconservative or very conservative for high strength stainless steel tubular sections. Hence, a unified web crippling equation with carefully calibrated coefficients for cold-formed stainless steel tubular sections is proposed. Furthermore, tests on combined bending and web crippling are also described in this paper. The test strengths are also compared with the design strengths obtained using the American and the Australian/New Zealand specifications. It is shown that the design strengths predicted by these specifications are generally conservative for tubular sections subjected to combined bending and web crippling. In addition, the yield line mechanism analysis is used to investigate the web crippling behaviour of cold-formed stainless steel tubular sections.