A Comparative Analysis of the Lateral-Torsional Buckling Resistance of the Hot-Rolled and Welded Sections

This paper presents a comparative study of several design approaches for evaluating the lateral-torsional buckling resistance of steel girders with doubly symmetric I and H cross-sections, both hotrolled and welded. The investigated methods include the general method and alternative approaches specified in EN 1993-1-1:2006 and EN 1993-1-1:2022, as well as simplified procedures that avoid the explicit evaluation of the elastic critical moment Mcr. A numerical application on an IPE 400 beam is used to quantify the influence of the chosen method on the resulting non-dimensional slenderness, reduction factors and design bending resistances. The results highlight the difference between methods, show that the direct simplified procedure leads to the most conservative resistance, and underline the conditions under which simplified approaches may become unconservative for lateral-torsional buckling verification.