04-24-2017 05:20 PM
The problem in the supplied model data is that the force is not applied correctly. You are using total per object so all force magnitudes are the same. To match the results in the full model, you need to remove the forces on the dependent grids (22, 23, 24, 42, 43) or cut the forces on the 10 edge nodes (5 independent and 5 dependent) in half:
To get a uniform displacement on the outer face, the loads on the edge nodes should be half of the load on the interior nodes for both the full and sector model. If you are loading both the independent and dependent nodes in the sector model, the load magnitude on the corner nodes should be 1/4 of the interior nodes:
05-15-2017 06:27 AM
Thank you for your great explaination.
I modified my model like your suggestions and i get the same displacements like you. But if you apply centrifugal inertia as load the displacements aren't the same (sector vs. full model) Is this because we can't exclude the dependent nodes from this "volume load" ? Also if you choose tangential as displacement direction instead of magnitude in subcase radial load the displacements aren't the same (sector vs. full model)?!?
thank you very much
05-15-2017 09:02 AM
Please post your current models. The One Drive link in the post from 3 weeks ago has expired.
05-15-2017 09:07 AM
05-15-2017 09:42 AM
The magnitude of your centrifugal load (9000000 rpm) results in a radial displacement on the order of 640 mm in a disk with an undeformed outer radius of 50 mm. This is way beyond small displacement. The other two load cases have radial displacements of 0.025 mm ("1kN Radial" subcase) and 0.018 mm ("radial new" subcase) and match well.
If the rotation load is reduced to a more reasonable value, say 90000 rpm, then the results compare well with a radial displacement of 0.016 mm.
05-15-2017 01:10 PM
oh sorry i forgot to reduce the value. I only loaded the model to see what happens with higher load. Yeah the radial displacements are matching very well but what is with the tangential displacements why they don't match?