Steel Buildings in Europe

Part 10: Technical Software Specification for Composite Beams 10 - 19 Table 5.1 C 1 and C 2 factors Loading C 1 C 2 1,35 0,59  L  L 1 + 2,92  3  (2,44 – 3,24  ) C 1 1,13 0,45 LTB slenderness The LTB slenderness is calculated as: cr y y LT M W f   where: W y = W pl,y for a class 1 or 2 cross-section W y = W el,y for a class 3 cross-section W y = W eff,y for a class 4 cross-section Reduction factor The reduction factor is calculated according to EN 1993-1-1 § 6.3.2.3 for rolled profiles: 2 LT 2 LT LT LT 1        but: 1 LT   and: 2 LT LT 1    where:     2 LT LT,0 LT LT LT 0,51          The parameters LT,0  and  may be given in the National Annex to EN 1993-1-1. The recommended values are: 0,4 LT,0    = 0,75  LT is the imperfection factor depending on the LTB curve to be considered for hot rolled profiles, according to EN 1993-1-1 Table 6.5: If h / b f  2 Curve b  LT = 0,34 If h / b f > 2 Curve c  LT = 0,49