The buckling stiffeners must be connected with the buckling panel with "normal" elements (thickness t > 0 mm).
During the calculation, I get a warning that some elements are connected to the buckling panel, but are not defined like stiffeners (see Image 01). What should I do?
Answer:
In the cross-section shown in Image 02, members Nos. 8 and 9 are defined as buckling stiffeners and connected to the buckling panel with null element No. 5 or No. 6 (thickness t = 0 mm).
The buckling stiffeners must be connected with the buckling panel with "normal" elements (thickness t > 0 mm). For example, you can delete null elements Nos. 5 and 6 and connect elements Nos. 8 and 9 directly to the buckling panel (Image 03).