Some Aspects of Buckling Behavior of Channel Section Members Under Eccentric Compression

Abstract

The buckling behavior of short length thin-walled cold-formed steel (TWCFS) columns of lipped channel cross-section is considered in the paper. The problem of buckling loads and the load carrying capacity of TWCFS members subjected to simple loading systems (pure bending or uniform compression) has been with satisfactory accuracy solved within the theory of thin-walled structures, as well as in design code specifications. However, the same problem concerning members subjected to combined loadings (compression and bending, eccentric compression) is still an open question [3]. The Eurocode [1] gives accurate predictions of the buckling load and ultimate strength of TWCFS members under concentric axial compression , but is less accurate in the examination of eccentrically compressed columns. TWCFS short length members are usually members of Class 4 sections [1]. Since these sections are prematurely prone to local or distortional buckling and they do not have a real post-elastic capacity, a failure of such members is initialized by the local-global interactive buckling of plastic-elastic type [2]. Thus, examination of buckling behavior of such members is of substantial importance in the case of eccentric compression, which has not been entirely recognized so far.