Rotational coordinate system

NAZ

Hi 

I'm a new mecway user and want to know if it's possible to create/import a rotational coordinate system in mecway. I want to simulate a band around a cylinder with an anisotrophic material. The U axis of the elements, as exaple, should follow the arc tagential (The band is made out of fibers around the cylinder). I can change the element orietation manually but if you have several thousand elements it's not very helpful.

 Thanks for your help

Tobias

Victor

Currently, the only practical way is to generate the band using Mesh tools -> Rotate/copy and check the Rotate element axes box.

NAZ

Hi Victor

That's what im trying at the moment. I will Rotate/copy a slice of the band around the z-axis. 

Thank you for your help

Tobias

NAZ

Hi Victor

I have two other questions. 

Do i have to merge the nodes of the elements which i copy/rotate? When i simulate the 3d model the fibers expand several meters. This didn't happen with the automeshed version and isotrophic material.

Thanks

Victor

Yes, you'll have to use Mesh tools -> Merge nearby nodes. In general, to see if elements are joined together properly, use View -> Open cracks.

NAZ

Hi Victor 

Thanks for your reply. I tried to simulate only a section of the cylinder to bring simulation time down. I used mirror to make sure both planes of symmetry have the same structure and nodes. Then i used cyclic symmetry. But when i try to solve the simulation following error appears on nodes of the plane:

Error: Incompatible constraints on node 26292.

Do you know what the problem could be?

Victor

Cyclic symmetry is a bit fussy about having other constraints on the symmetry nodes. Some combinations are allowed but some aren't. The slave nodes already follow the masters so there's no need to constrain them.