D5.B.6.4 Clause 6.3.2.3(1) – LTB for rolled sections or equivalent welded section
The FR-NA provides equations to evaluate the λLT,0 and αLT factors given in clause 6.3.2.3
For rolled doubly symmetric sections use:
Note: Since EN 1993-1-1:2005 limits the value of λLT,0 to 0.4, STAAD.Pro limits λLT,0 to a maximum value of 0.4.
For welded doubly symmetric sections use:
For other sections:
λLT,0 = 0.2
αLT = 0.76
And for all sections, β = 1.0
These equations and factors are then applied to equation 6.57 of NF EN 1993-1-1 to evaluate the Lateral Torsional Buckling reduction factor χLT.