# Cyclic region

Member

I am interested in the deflection of following plate:

The plate is a cycle so i just modelt just 1/12 of the plate as you can see above.

For the symmetrie i used a cyclic region as you can see in following picture:

I have done this for the part which you can see above, for the brown one, the gray one and the small green seal.

I have modelt the bolts as you can see below:

there is a bolt pretension on the bolts and in step 2 they are locked.

I connected the parts with a frictional contact.

The brown part have a fixed support on the bottomside.

In step 2, I obtained a pressure as you can see below:

When I press solve I get following warnings:

and following errors:

I have attached my solver output file

Unfortunately there is no error file at the link mentioned in the solver output file.

Thank you very much for your help.

Best regards

Bokaj

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• Member

At the end of the solve.out file is the following

```*** FATAL ***              CP =   151.312  TIME= 19:03:21
The internal constraint equation 224199 share degrees of freedom with
the constraint equations along the edge of the cyclic symmetry sector.
This is not allowed. Please modify your contact pair to avoid this.
```

Do what it says and you will get rid of this error.

Try to use simple symmetry instead of cyclic symmetry.

• Member

So there is no chance to use the cyclic symmetry in combination with a frictional contact? Because there is no chance that they do not shear an edge?

So the only chance is to use an frictionless support instead of the cyclic symmetry?

So is there any chance to show the result of my calculation expanted to a whole cycle?

Best regards

Bokaj

• Member
edited December 2020

Yes, there is a chance to keep the cyclic symmetry. You just can't have any node in that set also be in another constraint equation.

Here is one problem; you have this red face for some connection that includes a two edges of the cyclic symmetry set. If instead of a whole face, you imprint a washer-sized circular edge on that face around each hole and select the washer face instead of the whole face, that would prevent a constraint equation from sharing nodes with the cyclic symmetry set.

• Member

Thank you very much!

This has solved my problem.