Buckling eigenvalues with quad and beam elements

Dear all,

I want to calculate the buckling eigenvalue for the pilon. I tried to calculate it with ASE and DYNA as well, with over 100 eigenvalue results, but i didnt get the desired results.
I’m making a cable-stayed bridge and in my structure I have a deck with quad elements and a pilon with beam element. In the quad elements there is a big tension, therefore I’m getting eigenvalues of warping buckling in the quad deck but I’m not interested in these results.

Which program (ASE or DYNA) should I use? How can I get the eigenvalues for the pilon?

Thanks in advance,
Nándor Király

V2_model.sofistik (1.2 MB)

Finding buckling eigenvalues when you have area elements with many lower local modes may be quite difficult.
I would try eige parameter LMIN AUTO or LMIN “value” to skip those modes but there is always danger of skipping true pylon mode.
Other options are to manipulate area elements stiffness so they dont buckle or apply aritifcial equivalent load to pylon that will cause forces only in it.

Thank you for your advices. I’ll definitely try them out.