Local buckling behaviour of thin-walled members with curved cross-section parts

In this paper the buckling behaviour of thin-walled members with cross-sections with curved parts is investigated. Due to the curved parts, shell-like buckling is a potential mode of failure. The objective of the research is to understand whether shell-like buckling behaviour might be governing in practical cold-formed steel members. For this aim, numerical studies have been carried out, involving linear buckling analysis as well as nonlinear shell finite element analysis with imperfections, by considering a large number of various cross-sections. Standardized capacity prediction has also been completed, based on elastic critical loads by using the direct strength method, and the results have been compared to that of shell finite element analyses. Based on the results it is concluded that shell-like behaviour might be critical in certain cases, but only in case of unusual cross-section geometries. It was also found that the simple direct strength capacity prediction can reasonably be used in most of the cases.