The lateral buckling supports (top or bottom) that are considered in the calculation of the elastic critical moment depend on the shape of the bending moment acting in the beam.
According to NEN EN 1993 1 1 + C2 + A1:2016/NB:2016 (NB.74) and (NB.75), only one set of lateral supports – either top or bottom – shall be taken into account in the calculations:
