Hi all,

I am working on some column buckling analysis in SW simulations and needed help with the fixed-pinned geometry analysis.

My problem is pinning the column on the top because I have a wedge tip (like a piece of pie). I have tried applying a roller to different parts of the column but my simluation result for the critical buckling load does not correspond very well with simple Euler's buckling analysis equations:

P(critical)=(pi^2*E*Iz)/(K*L)^2

where K = 0.699 for fixed-pinned geometry.

Again, my results correspond well with the fixed-free simulations, but are not working out for the fixed-pinned geometry, I think due to the wedge shape of the tip and incorrect restrictions on the model.

I have attached the model. The wedge tip is where the force is applied, and where the column is pinned. The bottom flat end is the fixed end.

Thanks for your help in advance.

Omid

Hi Omid:

I got a difference from your formula of less than 3%. I used the BEAM functionality because it's fairly easy to apply the boundary conditions. You may have already tried this but, right click on the solid body in the simulation tree and choose "treat as beam". Next I assigned a pinned end to the wedge tip. I attached a screen shot of the joint settings in the fixture property manager. Essentially I just restricted translations in-plane (relative to the selected plane), but allowed a vertical translation of the joint (there is a purple-colored, downward unit load arrow there, too). I also allowed rotations about the joint with the exception of axial rotation. This solves in just a few seconds (presumably because it's using BEAM elements which solve super-fast). I hope this helps a little. - Tony