Simplified criterion for second order effects of isolated members: the slenderness λlim
Eurocode 2 part 1-1: Design of concrete structures 18.104.22.168 (1)
Second order effects may be ignored if the slenderness (λ = l0/i) is below a certain value λlim.
The recommended value for the slenderness λlim follows from:
|λlim = 20⋅A⋅B⋅C / √n||(5.13N)|