How do I get 2d modes from my modal analysis only?

Christian Nörenberg

Hi,

I want to do a 2d modal analysis with the attached model.
Inner diameter: 20 mm
Outer diameter: 30 mm
Real thickness: 10 mm (but of course the model is flat)

I used the PSHELL property with thickness = 10 mm, so there is no actual third dimension.
When I look at the results with hyperView, I found some 3D modes like the shown one.

Question:
How can I tell hypermesh / optistruct, that I my problem has 2 dimensions only and that I want to analyze only the xy plane?

Thanks for your help!

2d_donut_example.hm

2d_donut_example.mvw

Ben Buchanan

This is not a super elegant solution but could you constrain every node in the out of plane direction?  Otherwise I am not sure it is possible to convince HW that it is in flatland instead of sphereland.