ABSTRACT
The study presents the results of steel I-beams’ numerical analysis performed using Finite Element Method implemented in ABAQUS software. An influence of bimoments restraints on critical moment of bending and load-bearing capacity of steel I-beams were investigated. Studied beams were bisymmetric I-section, single span and fork-supported at both ends. An external load was applied as a concentrated force in the middle of the span. Geometrically and materially nonlinear analysis with imperfections (GMNIA) was applied. The initial curvature was obtained from the first mode of Lateral-Torsional Buckling in LBA in ABAQUS software. The amplitude of initial imperfection was calculated accordingly to new LTB design rules and their derivation (the Snijder’s approach). Results were compared to Eurocode’s “General Formula” and LTBeamN software. Bimoment restraints were defined as steel plates connected to both flanges in a plane parallel to the element’s web. The side plates working as a bimoment restraints were added to the computational model for different values of initial external load, which allowed to estimate its strengthening effect in existing I-beams.
