Influence of flexural residual stresses on the stability of compressed angles: Fid-Bau Portal

Influence of flexural residual stresses on the stability of compressed angles

Costa Ferreira, C.M. / Rondal, J.

AbstractStructural steel elements that are obtained by cold forming become more and more popular in steel construction. Indeed they are lighter in weight and thus provide appreciable savings compared with the usual hot rolled sections.Because they are obtained by cold forming, two kinds of residual stresses occur: membranar and flexural stresses. The flexural residual stresses are usually larger than the membranar ones. However the ECCS (European Convention for Constructional Steelwork) column buckling curves were established on the basis of longitudinal membranar residual stresses only, in addition to geometrical imperfections.Using a non-linear computer program, the authors investigate the influence of longitudinal flexural residual stresses on the carrying capacity of cold formed angles. This kind of section is now widely used for erecting large transmission towers. Strain hardening due to cold forming is taken into account in the present study.From the numerical results obtained, conclusions are drawn on the suitability of European column buckling curves for cold formed angles.