Shell to Solid Links in ProM

[peglor]

Is there an easy way to link shells and solids in a ProM model? I'm trying to build a model which contains a mixture of solids and shells but ProM won't run it, saying it's inadequately constrained. This inadequacy, I'm guessing, is due to there not being links between the shells of one part of the model and the solids of another. I have a full face of one of the bottom parts constrained in all degrees of freedom and a cylindrical coordinate system set up to constrain the cylindrical part to move in R and Z, but not in theta (The cylinder is being loaded at its top edge).

The shells in the model form a cylindrical part with a flange at the bottom. This flange meets face on with the surface of a plate made from solid elements. Is this an acceptable method of having the parts interact?

An alternative method would be to make the flange at the base of the cylinder from solid elements and have a corner of this flange meet the cylinder of shell elements. This, I'm guessing will lead to very high local stress and an inconsistent model since shells model the mid plane of a solid.

I'm also wondering why ProM sometimes spots that shells coincide with solid surfaces and links them automatically when the run starts and somethimes won't recognize that a shell and a solid have a common surface even when you try to manually link them. All help will be greatly appreciated.

 

[LRW]

Peglor-
Are you using mid surfaces? According to the book that I have "Pro/Mechanica Tutorial Structure" by Roger Toogood, you shouldn't have to do anything more than make sure that the shells fully intersect the solid (in Pro/E), then start mechanica:
Idealizations
Mid surfaces
New - Constant
Choose pairs or single surfaces
Compress
Shells only
Compress model
Show paired - should not see solid
Show compressed - should show shells and solids
Go back to settings and make sure that Use Pairs is selected (again if using mid sufaces)
Define constraints and loads as usual, check, run.
The tutorial says that this kind of model is more processor intensive and also said the run times are very long.

I hope that this helps!
Cheers-
LRW

L.R. Weidner

 

[peglor]

I'm using a model built in ProMechanica rather than an integrated mode model from ProE. The problem is what I have in the model is one part made from shells and a solid part. Some shells in the shell part coincide with a surface of the solid. I need to link one to the other, but this appears to only be possible after the parts have been meshed and by selecting individual pairs of elements from the model and telling ProM to link them.

I have a certain number of elements which will link, while more often the program won't acknowledge that the elements can be linked at all.