LATERAL-TORSIONAL BUCKLING ANALYSIS OF ASYMMETRIC THIN-WALLED BEAMS
LATERAL-TORSIONAL BUCKLING ANALYSIS OF ASYMMETRIC THIN-WALLED BEAMS
DOI:
https://doi.org/10.22337/2587-9618-2026-22-3-155-174Keywords:
lateral-torsional buckling (LTB), thin-walled steel beam, Vlasov’s beam theory, elastic critical moment, finite element analysis (FEA)Abstract
A review and analysis of domestic and international design codes (Eurocode EN 1993-1-1, American standard ANSI/AISC 360-22 and Russian standard SP 16.13330.2017) regarding the lateral-torsional buckling of flexural elements indicate that current standards lack a universal solution for evaluating the lateral-torsional buckling stability of beams with arbitrary cross-sections under arbitrary loading conditions. The available litera-ture provides design recommendations for the buckling analysis of symmetric and asymmetric I-beams and channels under a limited number of loading configurations and boundary conditions. Therefore, evaluating the buckling stability of non-standard beams (such as strengthened sections, which often exhibit complex and asymmetric geometries) is significantly hindered by the absence of practical engineering methods. This paper proposes a method for analyzing the elastic lateral-torsional buckling stability of thin-walled steel beams with asymmetric cross-sections under arbitrary loading scenarios and boundary conditions. The method is developed based on the analytical solution to a system of differential buckling equations in accordance with Vlasov's thin-walled beam theory, considering the elastic stage of material behavior. The proposed method is formulated in compliance with the design approaches adopted in SP 16.13330.2017, making it suitable for inte-gration into the regulatory framework. The primary advantage of this method lies in its versatility. The validity of the method is confirmed by calculation examples and verification finite element modeling performed using the Simcenter FEMAP with Nastran software suite.
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