Stainless steel stub columns subject to combined bending and axial loading

Abstract

This paper examines the behaviour of cold-formed stainless steel stub columns where the material follows a Ramberg–Osgood stress–strain law. The stub column length is varied to examine the effects on the failure capacity when the stub columns are subjected to varying magnitudes of combined bending and axial compression loading. The paper follows the work reported by the same authors in 2003 [Macdonald, M, Rhodes J. and Kotelko M. Behaviour of stainless steel columns under combined bending and axial compression loading. Proceedings of the 10th Symposium on Stability of Structures, Zakopane, Poland. 2003], but here, three different methods of analysis are employed: (i) the Eurocode 3, Part 1.4 design code using an enhanced 0.2% proof stress combined with a full section moment capacity within the interaction formula with nominal levels of loading eccentricity, (ii) the same approach using the Polish cold formed carbon steel code PN-90/B-03200 to ascertain its applicability and (iii), the same approaches but using the true eccentricity with reference to the unsupported length of the columns. The results are compared with those obtained from a series of compression tests performed on cold-formed stainless steel Type 304 stub columns of lipped channel cross-section for the same conditions.