Steel Buildings in Europe

Part 10: Technical Software Specification for Composite Beams 10 - 18 When shear buckling does not need to be considered and the shear criterion  V is higher than 0,5, M-V interaction must be checked using the following criterion (EN 1993-1-1 § 6.2.8): V,Rd Ed MV M M   where: M0 y w 2 pl,y V,Rd / 4   f t M W A w         2 pl,Rd Ed 2 1           V V  A w = ( h – 2 t f ) t w 5.2.6 Resistance to Lateral Torsional Buckling (LTB) Design criterion If the beam is assumed to be fully laterally restrained, no LTB verification is performed. If the beam is restrained at the supports only, the LTB criterion is calculated as follows:  LT = M Ed / M b,Rd where: M Ed is the maximum design moment along the beam M b,Rd is the design LTB resistance that is determined according to the appropriate LTB curve and the LTB slenderness as described below. Elastic critical moment The elastic critical moment is determined from the following equation:               2 g 2 2 g z 2 2 t z w 2 z 2 1 cr C z C z EI GI L I I L EI M C   where: z g = + h /2 (the transverse loading is assumed to be applied above the upper flange) The C 1 and C 2 factors can be taken from Table 5.1.