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#1 Re: Code_Aster usage » HELP: usage of PENE_MAXI in DEFI_CONTACT when ALGO_CONT='PENALISATION' » 2023-09-12 09:40:25

I have noticed that PENE_MAXI must be set the same value for all contact zones to be respected.
GLIS_MAXI is not respected at all, the only thing that change the result is COEF_PENA_FROT.

#2 Re: Code_Aster usage » Problem with defining the contact situation » 2023-09-03 20:01:57

Hello, what about to solve one STAT_NON_LINE with high soft spring stiffness and then reuse the step with different AFFE_CARA_ELEM where the stiffness will be low for the same loading.

#3 Code_Aster usage » how SANS_GROUP_NO_FR works » 2023-09-03 13:11:57

jacob
Replies: 0

Hello,
I would like to ask what actually SANS_GROUP_NO_FR does? I know that it should be used on nodes where is prescribed symmetry and that I understand, but if I exclude all the nodes on the slave surface

_F(ALGO_CONT='STANDARD',
                                ALGO_FROT='STANDARD',
                                COULOMB=0.1,
                                DIST_ESCL=offset,
                                GROUP_MA_ESCL=('sc_ring', ),
                                GROUP_MA_MAIT=('mt_ring', ),
                                SANS_GROUP_NO_FR=('sc_ring', )),

I would expect the contact to behave as it would be without friction.
But, instead all the nodes have status 1 (adhesion). Does that mean that using SANS_GROUP_NO_FR means that all the nodes which are in contact will be glued, so there is no solving for slip/adhesion but everything is assumed to be adhesive?

#4 Re: Salome-Meca usage » Use deformed mesh from Stage1 in Stage2 » 2023-09-01 14:49:19

hello,
you can just do

STA_NL = STAT_NON_LINE(....)

...


STA_NL = STAT_NON_LINE(reuse=STA_NL,
                 
                       ETAT_INIT=_F(EVOL_NOLI=STA_NL),

#5 Re: Salome-Meca usage » [solved] .mess printed in real time with Salomé-méca » 2023-08-23 17:39:13

hello, it is somewhere in tmp or Temp when running. Called fort.6

#6 Re: Code_Aster usage » contact over simmetry condition boundary [SOLVED] » 2023-08-12 10:29:27

I think I never had a problem when doing contact with symmetry, just when you want to compute reaction, you have to use contact's RN and not FORC. And you don't have to exclude nodes lying on the symmetry.
Problem comes with different bc like LIAISON_MAIL or if slave and target have common nodes.

#7 Re: Salome-Meca usage » Error in axysimmetric simulation » 2023-07-18 19:36:51

Hello, try this. However I don't know why you used or how works AXIS_FOURIER.

#8 Re: Salome-Meca usage » Prepocessing software for groups creation » 2023-07-13 17:35:59

Solidworks and other commertial softwares do it differently. If you change something all the entities that were in some feature stay there or there will be some message that something is missing. Shaper just remembers what entities names were there.

Yeah, and the file has to be named differently otherwise it will not update.

If you want compatible mesh from two imported shells just apply partition. Or, you can project the mesh from one edge to another.


I thing there exists some mesh converters to med format.
Vega Translator from *.nas to *.bdf
Meshio
export from Ansys to cgns

#9 Re: Salome-Meca usage » Prepocessing software for groups creation » 2023-07-12 22:11:00

It is nicely explained here youtube.com/watch?v=GKn5kAYmfQE
Partition.
Then, you can always change the file in import.

#10 Re: Salome-Meca usage » Prepocessing software for groups creation » 2023-07-12 20:41:41

For example, I prepare the geometry completely in external cad and then import it to shaper, and do partition. Then, I just create groups for meshing and bc.
Like I said before, if I change my cad and update the import, if the changes are "not significant", it will all update as well.
The only problem is with the references done using names.

#12 Re: Code_Aster usage » Contact pressure post-processing » 2023-06-24 12:28:03

Hello, what about displaying the pressure from CALC_PRESSION only on elements where is contact status 1 or 2?
Of course CALC_PRESSION will give results in all areas not only in contact area, because it calculates stress in normal direction.

#13 Re: Salome-Meca usage » Prepocessing software for groups creation » 2023-06-24 12:21:17

Hello,
well, if you import a part to shaper and create groups, then change the import file, the groups update as well.
However, it will work only if you change the part in your cad in a way that some faces or edges will not be deleted or added (you have to change for example only some dimensions). Shaper works like freecad, so all references are done according names. Thus, if you change you geometry more significantly some faces, edges will be wrongly selected after the update.
If you import each part separately, then you do not have to change at least everything, only the changed part.

#14 Re: Code_Aster usage » problem with DOF » 2023-06-20 16:04:07

Hello,
no surprise since you have in EXCIT only charge

reslin = MECA_STATIQUE(CARA_ELEM=elemprop,
                       CHAM_MATER=fieldmat,
                       EXCIT=(_F(CHARGE=charge),
                              _F(CHARGE=encastr)), # added
                       MODELE=model)

#15 Re: Code_Aster usage » Problem with defining the contact situation » 2023-05-25 17:14:33

I am facing also this kind of problems.
Increasing number of NPREC to 10 or 12 or set it to -1 will help with this kind of error, however I still don't know why this is happening.
Or, of course, increasing the stiffness of soft springs.

#16 Re: Code_Aster usage » contact - simple ring » 2023-05-02 22:31:08

All right. Correct solution is this.

Somehow friction helps.

#17 Re: Code_Aster usage » contact - simple ring » 2023-05-01 13:48:36

Well, but then the results are not right.

However, I have found out that INTEGRATION = GAUSS works, but don't know why. The mesh is compatible. And I don't get field CONT.
It should be easy to converge even with AUTO.

#18 Re: Code_Aster usage » contact - simple ring » 2023-04-30 12:46:30

Thank you,
however I don't think that using CONTROLE is all right. You just say give me results after 10 iterations, but it doesn't mean it has converged.

#19 Code_Aster usage » contact - simple ring » 2023-04-30 09:50:12

jacob
Replies: 5

Hello,
could somebody help me and tell why this contact does not converge (problem is with the second one - ring).
I have tried everything.

Mesh is nice, I use penalization and it behaved the same even if the ring is fixed so the problem is not free movement.
Cutting the timestep also doesn't help.

Thank you

#20 Re: Code_Aster usage » Structure Optimization with Code_Aster » 2023-04-05 21:32:42

however if I understand it correctly this is not SIMP, or some algorithm where the stiffness of the elements just changes and there is no actual removal of the elements. I think that would be better.

#21 Re: Code_Aster usage » Constrain DZ displacement of a node with DX » 2023-03-28 21:58:24

I mean manually homogenize it using some general formulas for your application to compute EN, ET and so on.

#22 Re: Code_Aster usage » Constrain DZ displacement of a node with DX » 2023-03-28 20:32:33

then probably not, but an orthotropic material might work. Could you homogenize the composite?
I don't have any experience with composites in CA.

#23 Re: Code_Aster usage » Constrain DZ displacement of a node with DX » 2023-03-28 17:55:03

https:// code-aster.org/V2/doc/default/en/man_u/u4/u4.44.11.pdf

page 35

#24 Re: Code_Aster usage » calculate total force via Axis FORC_NODA » 2023-03-28 10:23:11

if you use FORCE_CONTOUR, it is as if you applied pressure on the whole annulus, so total force is  FORCE/(area of the whole annulus, circle in your case).

With force_nodale it would be FORCE/nodes I guess.

Just do some simple case in 3d and compare.

#25 Re: Code_Aster usage » Constrain DZ displacement of a node with DX » 2023-03-27 21:18:05

LIAISON_UNIL (UNILATERAL_CONSTRAINT) formulation