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## #1 2016-07-06 09:00:44

highpressuretube
Member
From: Werther
Registered: 2014-12-02
Posts: 48

### Rotational Symmetry Boundary Conditions

Hi all,

I try to model a square profile rotating within another square with simple contact so far. However I just don't get how to set up the model with appropriate BCs. (squarerotation.jpg)

Any advice? What I did so far to apply the rotation:
Set up additional point at coordinate base named: TORQUE, apply DRZ 0,1 to point, link point to inner mesh with LIAISON_SOLIDE.

Problems:
1) No symmetry between the edges marked in yellow, thus wrong. (compare 2nd picture)
2) Missing deformation of inner square because of LIAISON_SOLIDE, thus not really useful.

Ideas:
1) Use LIAISON_GROUP to set up cyclic symmetry
2) LIAISON_SOLIDE ONLY to the edges with cyclic symmetry

Result:
1) Following error:

``````!-----------------------------------------------------------------------------------------------------------------------------------!
! <EXCEPTION> <MODELISA8_77>                                                                                                        !
!                                                                                                                                   !
!  Il y a un conflit dans les vis-à-vis des noeuds. Le noeud  N12 est                                                               !
!  à la fois le vis-à-vis du noeud N38 et du noeud N5.                                                                              !
!                                                                                                                                   !
!  Conseils :                                                                                                                       !
!    - Si la distance entre les deux surfaces à apparier est grande devant leurs dimensions, précisez l'isométrie qui permet de les !
! superposer par l'intermédiaire des mots-clés CENTRE, ANGL_NAUT et TRAN.                                                           !
!    - Si les maillages sont incompatibles, utilisez plutôt le chargement LIAISON_MAIL.                                             !
!-----------------------------------------------------------------------------------------------------------------------------------!``````

Meshes should be compatible since it es 11 nodes on each edge distributed via wire_dicretization and local length, shouldn't it?
2) did not get so far because of 1)

Any ideas, help suggestions are appreciated.

Regards,
highpressuretube

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## #2 2016-07-06 09:02:50

highpressuretube
Member
From: Werther
Registered: 2014-12-02
Posts: 48

2nd picture

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## #3 2016-07-06 09:06:47

highpressuretube
Member
From: Werther
Registered: 2014-12-02
Posts: 48

### Re: Rotational Symmetry Boundary Conditions

And of course I forgot the mess file, sorry, here it is:

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## #4 2016-07-08 07:34:39

highpressuretube
Member
From: Werther
Registered: 2014-12-02
Posts: 48

*push*

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