Post-elastic Capacity of Thin-walled Cold-formed Steel Members

Abstract

The paper presents the possibility to apply the local plastic mechanisms to characterize the ultimate strength of thin-walled cold-formed steel members subjected to eccentric compression. In previous papers [13], [14], [18], the authors have shown that, for compression or bending, the failure of such sections modelled by localized plastic mechanisms characterize better the behaviour of thin-walled cold-formed short members in Ultimate Limit State. These models are consistent with the real failure mechanism of short members and were confirmed both by experimental tests and advanced elastic-plastic FEM analyses. Selected results from these studies are summarized in Chapter 2 of the paper. The main aim of the actual paper concerns the more complex problem of members subjected to combined loadings i.e. compression and bending or eccentric compression. The failure model of slender members in eccentric compression is still an open question. In an attempt to solve this problem, the authors propose a consistent methodology which applies the General Method of EN1993 Part 1-1, in which the section resistance, prone to bending and compression, is characterized through plastic mechanism failure models.