Flexural buckling can occur around two axes:
- about the strong axis (y’ or u)
- about the weak axis (z’ or v).
By default, Diamonds sets the buckling length of bar equal to the bar length. If, at the moment of opening the dialogue, you had the buckling lengths calculationed 
, you will find the calculated values in the upper fields.
For concrete sections the option “verify buckling for additional eccentricity” will be visible (more information here).
