Lateral buckling of steel beams. Compared analysis of CTE DB SE-A, EAE and EC3 codes

The Basic Document, Structural Safety, Steel of the Spanish Technical Building Code provides mathematical expressions to obtain the lateral buckling resistance of hot-rolled steel beams. These expressions include a coefficient, {\displaystyle C_{1}}, that accounts for variation of the bending moment along the beam. However, this document only provides values for linear diagrams of bending moments. The instruction for Structural Steel, a copy of the latest version of Eurocode 3, does not include any method to obtain the elastic critical moment. On the contrary, a table with correction factors applicable to different types of bending moments diagrams is included. In this document both procedures have been combined and results have been compared to those obtained using other versions of the Eurocode 3. Finally, tables have been provided to ease the design of hot-rolled steel beams while preventing the lateral buckling.