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#1 Re: Code_Aster usage » Contact CONTINUE with SANS_GROUP_NO between slave surfaces » 2021-06-11 05:51:34

Hello Micke,
I asked the same question a few years ago but I guess it hasn't been improved yet:
https://code-aster.org/forum2/viewtopic … 704#p50704

Konyaro

#2 Re: Code_Aster usage » Run code_aster file with Matlab » 2021-04-23 05:56:50

Hello,
if you search for "run aster with python" on the forum you will get many results you can convert to Matlab. I use the following python script:

if os.name == 'nt':
    print('Lancement du calcul sous Windows')
    command = '{!s} {!s}'.format(os.path.join(repAsRun, 'as_run.bat'), export_file)
else:
    print('Lancement du calcul sous Linux')
    command = '{!s} shell -- as_run "{!s}"'.format(os.path.join(repAsRun, 'salome'), export_file)
process = subprocess.Popen(command, shell=True)
process.wait()

- repAsRun : path to your CA installation
- export_file : your export file

Konyaro

#3 Re: Code_Aster usage » Get the new coordinates of a deformed mesh » 2021-04-23 05:49:06

Hello,
your first solution should work, cf. attached file. Is it possible to share your comm file and mesh?

Konyaro

#4 Re: Code_Aster usage » [SOLVED] EXTR_TABLE does not work » 2021-03-22 09:22:13

Hello,
your object TBL is a tuple. If you do TBL[0].EXTR_TABLE(), it works. Nevertheless i don't know why it is a tuple...

Konyaro

#5 Re: Code_Aster usage » [SOLVED] Automatically generate filenames and units for .export file » 2021-03-04 17:03:26

Hello,
I often use the following without problems:

DEFI_FICHIER(ACTION='ASSOCIER',
             FICHIER=r'/usr/temp/Mesh.med',
             UNITE=3)
             
MAIL = LIRE_MAILLAGE(FORMAT='MED',
                     UNITE=3)

Don't forget the path of the file.

Konyaro

#6 Re: Code_Aster usage » Applying nodal displacements node by node » 2021-01-29 17:12:37

Hello,
you can do it easily with AFFE_CHAR_MECA_F, for instance :

def FdispX(INST, X, Y):
    R = sqrt(X**2 + Y**2)
    x = X / R * 0.05 * INST
    return x

deplX=FORMULE(NOM_PARA=('INST','X','Y',),
              VALE='FdispX(INST,X,Y)', FdispX=FdispX);

trans1=AFFE_CHAR_MECA_F(MODELE=model,
                        DDL_IMPO=_F(GROUP_NO='mondaiNai',
                                    DX=deplX,),);

Konyaro

#7 Code_Aster usage » LIAISON_GROUP: Il y a un conflit dans les vis-à-vis des noeuds » 2021-01-29 08:21:04

konyaro
Replies: 0

Hello,
I try to impose a cyclic condition on a compatible mesh with LIAISON_GROUP specifying ANGL_NAUT. I tried many different settings but always get the same error: "Il y a un conflit dans les vis-à-vis des noeuds [...]"

There is a similar post without solution:
https://code-aster.org/forum2/viewtopic.php?id=20628

Any hint welcome,

Konyaro

attached: MED, comm and mess files of a simple example.

#8 Re: Code_Aster usage » [Solved] Differences in convergence with different meshes » 2020-11-29 09:56:51

Hello,

Jesus wrote:

I don't know what do you mean with the file I use to mesh.

I meant a python dump file of your study (file --> Dump study).

I corrected the mesh and changed the contact parameters in order to make the simulation converge pretty fast.

Concerning the mesh parameters, you should rather ask your question on the Salome forum.

Attached mesh and comm file.

Konyaro

#9 Re: Code_Aster usage » [Solved] Differences in convergence with different meshes » 2020-11-23 20:40:28

There is something wrong with your mesh. There seems to be a common node to both parts. Can you share the file you used to mesh ?

#10 Re: Code_Aster usage » Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE) » 2020-11-22 08:04:21

Hello,
it is possible to simulate the beginning of the crash of your ball on the plate with Code_Aster but once the distortion of elements gets too high the simulation will stop. You should investigate other ways:

1) Use of linear tetrahedrons can help but it won't be enough anyway.
2) Adaptive meshing would be an option but doesn't exist in Code_Aster. Homard can refine a mesh but not remesh a deformed mesh. Different commercial software handle it.
3) An explicit solver is a good option but I don't know any good opensource ones.
4) SPH could be an option with good opensource codes.

Konyaro

#11 Re: Code_Aster usage » [Solved] Differences in convergence with different meshes » 2020-11-21 14:31:52

Hello,
there are a few strange things in your model. I changed the followings:
- blocked only the Y direction as the model is axis-symmetric
- added weak springs as the upper part Y direction is not constrained (the stiffness may be too high)
- added a penalty coef. (you should adjust it) for the contact
- changed the contact zone for a larger one
- activated the automatic time-stepping
- changed the ALGO_RESO_CONT to POINT_FIXE in order to facilitate the convergence.

Attached the comm file.

Konyaro

#12 Re: Salome-Meca usage » Salome filling rate error » 2020-11-21 07:34:08

Hello,
your example with hex elements works fine. The message you mentioned is not an error, it is just an information about the matrix.

Attached the message file.

Konyaro

#13 Re: Code_Aster usage » [SOLVED] Resultant of FORC_NODA nodal foces on a (intenal) Group » 2020-11-17 06:57:19

Hello,
glad to hear that the resultant forces on free nodes equal zero otherwise the system would not be at equilibrium.

Konyaro

#14 Re: Code_Aster usage » Non Convergence from shell to shell contact » 2020-09-08 07:05:20

Hello,
I'm not used to shell elements but re-orienting the contact surfaces leads to convergence. I also modified the contact in order to make it faster.

Konyaro

#16 Re: Code_Aster usage » <EXCEPTION> <COMPOR5_1> On ne trouve pas la courbe de traction » 2020-07-09 05:43:21

Hello,
you must add the 2 behaviors in STAT_NON_LINE:

COMPORTEMENT=(_F(GROUP_MA=('steel'),
                 RELATION='VMIS_ISOT_TRAC'),
              _F(GROUP_MA=('concr'),
                 RELATION='ELAS')),

Konyaro

#17 Re: Code_Aster usage » Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE) » 2020-07-08 08:49:38

Hello,
your case runs fine. It requires a lot of RAM as there are many nodes and you're using a direct solver. I guess that's the source of your problem. The Windows version doesn't depict the memory error messages. You should try to increase the amount of memory or reduce the size of the mesh.

In the attached files I switched to larger linear elements and changed a few things in your comm file: GROT_GDEP, contact, reuse for CALC_CHAMP, less steps as I don't want to wait for hours. It does converge well.

Konyaro

#18 Re: Code_Aster usage » [Solved]Advice needed on <EXCEPTION> <FACTOR_78> (DYNA_NON_LINE) » 2020-06-27 06:47:20

So it bears the question: how do one obtain surfaces or edges in 3D?

You must create groups, not new elements. The easiest way is to use "Create groups from geometry" in the MESH module. If you select a face it will create a group of 2D elements, if you select an edge it will create a group of 1D elements.

Given that, should I use Netgen ONLY for meshing the ball? Or should I avoid using Netgen at all?

You can use whatever you want. If you don't know what to choose I recommend quadratic tetrahedrons.

Konyaro

#19 Re: Code_Aster usage » [Solved]Advice needed on <EXCEPTION> <FACTOR_78> (DYNA_NON_LINE) » 2020-06-21 06:14:36

Moreover be careful, you mesh has quadrangles only on the surface

I just wanted to point out that one may think that a Netgen mesh with the option "Quad-dominated" produces a nice hexahedral mesh. This is not the case, the elements are pyramids connected to tetrahedrons.
Fake Hexas

#20 Re: Salome-Meca usage » [SOLVED] Get shared nodes in solids with different mesh elements » 2020-06-20 05:51:46

Hello,
there are similar posts in the salome-platform's forum. It's a bit tricky, you must add 2 sub-meshes in order to apply 2 different algorithms:

Mesh

Konyaro

#21 Re: Salome-Meca usage » Von-Mises Stress in Salome-Meca » 2020-06-20 05:10:36

Hello,
you can simply calculate them after your analysis:

resu1 = CALC_CHAMP(reuse=resu1,
                    CRITERES=('SIEQ_NOEU'),
                    RESULTAT=resu1,
                    TOUT_ORDRE='OUI')

and you will be able to display the Von Mises stresses called VMIS.

Konyaro

#23 Re: Code_Aster usage » [Solved]Advice needed on <EXCEPTION> <FACTOR_78> (DYNA_NON_LINE) » 2020-06-20 04:57:02

Hello,
there are a few mistakes in your model and the main issue is that you're meshing solids AND faces. You must simply define groups in the geometry and not duplicate faces. Moreover be careful, you mesh has quadrangles only on the surface. I corrected a few points in your comm files, it's converging nicely.

Ball

Konyaro

#24 Re: Code_Aster usage » [Solved]Advice needed on <EXCEPTION> <CONTACT2_11> (DYNA_NON_LINE) » 2020-06-08 05:40:18

Hello,
as stated in doc U4.44.11 §3.1.2, your master and slave must be surfaces or edges in 3D.

Konyaro

#25 Re: Salome-Meca installation » salome-meca for windows Error: Can not save file » 2020-05-30 06:01:19

Have a look at:
www. salome-platform.org/forum/forum_10/541818275