METAL BEAMS SUSCEPTIBLE TO OUT-OF-PLANE INSTABILITY DUE TO COMBINED COMPRESSION AND BENDING WITH GEOMETRIC IMPERFECTIONS

The parts of the second generation of Eurocodes are continuously published. The full set of the 2nd generation of these new European standards consists of 68 parts of Eurocodes, 15 Technical Specifications and 5 Technical Reports and they will all be available in 2028. The aim of the paper is to bridge the gap concerning one of the newest and the most complex UGLI (Unique Global and Local Initial) imperfection methods. According to EN 1993-1-1:2022, ultimate limit state design checks may be carried out using methods of analysis named hereafter as M0, M1, M2, M3, M4, M5 or EM. Both Eurocodes EN 1993-1-1:2022 and EN 1999-1-1:2023 state, as an alternative that to sway and equivalent bow imperfection the new UGLI imperfection method may be employed for global and member analyses. In previous papers, plane stability was mostly investigated. The method presented in this paper enables the computing of the amplitude of the initial imperfection of elements under compression bending susceptible to out-of-plane buckling, and is a generalization of Eurocode rules, which is valid only for members under compression. This work is a continuation of a previous work by Agüero, in which the way to compute the UGLI imperfection was generalized for flexural torsional buckling due to compression and lateral torsional buckling due to bending. Some examples are presented to show the agreement with GMNIA (Geometrical material nonlinear analysis of imperfect structures), tests and proposals with codes.