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#1 Re: Code_Aster usage » Issue with combined static results form different loads » 2022-03-06 16:09:52

Hi,

You should use CREA_RESU to convert RES into a result object that you can use in the last calc_champ.
CREA_CHAMP creates a field object but CALC_CHAMP works with a result object.
That is what the error message is saying in French:
...cham_no_sdaster (an object of type  cham_no) n'est pas d'un type autorisé (is not of an authorized type) ...resultat_sdaster (the type needed that is resultat).

Cheers,
Ioannis

#2 Re: Code_Aster usage » [SOLVED] Save results of CALC_CHAMP() in for loop to MED file » 2022-01-15 09:05:46

Hi Luka,

In order to add more fields you have to use similarly a for loop to extract each one, you just have to change to the correct TYPE_CHAM and NOM_CHAM, which you can find in the CREA_CHAMP documentation. For example SIEF_ELNO and ELNO_SIEF_R.

Then, in CREA_RESU, since you will call it for a second time and more, enriching the result fields, you will have to add reuse=reslin and RESULTAT=reslin

sief = [None for i in range(0, N)]
affe = [None for i in range(0, N)]
for i in range(0, N):
    sief[i] = CREA_CHAMP(TYPE_CHAM = 'ELNO_SIEF_R',
                         NOM_CHAM = 'SIEF_ELNO',
                         OPERATION = 'EXTR',
                         RESULTAT = res[i],
                         INST = 0)

    affe[i] = _F(MODELE = model,
                 CARA_ELEM = elpr[i],
                 CHAM_GD = disp[i],
                 INST = i)

# create result file
reslin = CREA_RESU(
                    reuse = reslin,
                    RESULTAT = reslin,
                    OPERATION = 'AFFE',
                    TYPE_RESU = 'EVOL_ELAS',
                    NOM_CHAM = 'DEPL',
                    AFFE = affe)

#3 Re: Code_Aster usage » comm file for thermal expansion » 2021-07-19 20:39:22

Hi,

You can look in this repo in GitHub https: //github.com/Jesusbill/code-aster-examples
Tutorials 04-06 are about "Steady-state thermo-mechanical analysis of a cantilever beam with 3D solid elements", you can watch the videos in YouTube and find all the analysis files in the repo.
Let me know if you need any help.

Regards,
Ioannis

#4 Re: Introduce yourself / Présentez vous » Good morning » 2021-07-19 20:30:07

You can post as in any forum, but you cannot include www links in the text, this is the message you receive.
You can post a link that is not "correct" for example introducing a space or any other symbol like: https ://code-aster.org

#5 Re: Salome-Meca installation » Salome Meca 2020 installation on Ubuntu » 2021-06-23 23:22:37

Hi,
This message that you show is when you try to run Salome-Meca, that is after the installation has taken place.
You should get I suppose some errors during the installation of the software, which should have some hint about the issue.
If you can copy-paste the output in the terminal during installation maybe someone can help.
Other than that the warnings you see are typical and should not cause a problem.
Good luck,
Ioannis

#6 Re: Code_Aster usage » Shell results visualization » 2021-03-26 15:10:40

Hi VonPire,

I don't have experience using other post-processing tools so I cannot help any further here.

Ioannis

#7 Re: Code_Aster usage » Shell results visualization » 2021-03-24 18:51:22

Hi,

I'd be surprised if this could be done in ParaVis! It would be nice indeed.
The thing is that the "rmed" file doesn't necessarily contain the thickness of the shell element as a property - maybe it can be included if specified in IMPR_RESU (?), same thing for beam elements for example.

#8 Re: Code_Aster usage » [SOLVED]ASTK Unable to open terminal » 2021-03-21 14:55:44

Hi Sukumar,

It worked! smile
Thank you! I appreciate it!

Cheers

#9 Re: Code_Aster usage » [SOLVED]ASTK Unable to open terminal » 2021-03-21 02:32:51

Hi Roger,

I am facing the same problem with the terminal in astk. I have installed xterm but the problem is not solved.

Can you please elaborate on your solution? What exactly did you rename? And where did you place it?

Thanks in advance
Ioannis

#10 Re: Code_Aster usage » [SOLVED] Apply variable field of pressure (or any field...) » 2021-03-07 14:57:22

I see two problems, running your example.

1. FORC_NODA should have three components (FX, FY, FZ) but you are considering only one. Is it pressure? In this case use PRES instead of FORC_NODA in CREA_TABLE

2. TheTYPE_CHAM in CREA_CHAMP command if you use PRES should be NOEU_PRES_R

With these two modifications you can go through these steps

#11 Re: Code_Aster usage » [SOLVED] Apply variable field of pressure (or any field...) » 2021-03-06 02:17:40

Ok I see.
In any case I advise you to post a small working example (comm + med) so that anyone that wants to help can try it and play around.
Otherwise, it is difficult to get help I think.

#12 Re: Code_Aster usage » [SOLVED] Apply variable field of pressure (or any field...) » 2021-03-06 00:36:28

Hi,
You said 541 nodes but you are constructing a field of 540 nodes? Should be range(1, 542) to get N1, N2, ... N541

By the way this piece of code could be better written as:

node_list = [f"N{i_node}" for i_node in range(1, 541)]

Avoid using append in a for loop where possible because you are creating a new object every time, not so good performance-wise.
Also this way of string creation (using f"" and {} inside for variables) is much more readable

#13 Re: Code_Aster usage » Beams (POU_D_E) embedded into 3D Solids » 2020-12-08 00:14:00

Hi,

If the displacement connection between the ground and the pipes is good with your modelling assumptions then you can just go ahead and fix the rotational (twisting) DOFs of the beam elements. If your elements are not aligned with one of the global directions you can use LIAISON_DDL to restrain the local DRX of each pipe, that is you need to fix just one node in each pipe so that the element cannot rotate around its local X axis.

That is what I did in a building model where I had columns that were carrying only axial loads and were pin-connected to the beams. You are actually just constraining a DOF that you do not use either-way in your model.

#14 Re: Code_Aster usage » Create a field from different Crea_Champ with Formule » 2020-12-01 14:56:29

Hi GPSalachs

I am showing here a simple example I used to extract the maximum velocities from an analysis (resDyna) and to create two fields, one with the squared values and one with the signed squared values. It can be helpful for your case. Or you already know this but your problem is how to consider two fields?

PS: you should put any code in brackets with the word code inside (see here h ttps://www.code-aster.org/forum2/help.php#bbcode)

f_square = FORMULE(
    NOM_PARA = ('DZ',),
    VALE = 'DZ**2'
)

f_signSq = FORMULE(
    NOM_PARA = ('DZ',),
    VALE = 'DZ*abs(DZ)'
)

vite_ch = CREA_CHAMP(
    OPERATION = 'EXTR',
    RESULTAT = resDyna,
    NOM_CHAM = 'VITE',
    TYPE_CHAM = 'NOEU_DEPL_R',
    TYPE_MAXI = 'NORM_TRAN',
    TYPE_RESU = 'VALE'
)

vite_fun = CREA_CHAMP(
    OPERATION = 'AFFE',
    TYPE_CHAM = 'NOEU_NEUT_F',
    # MODELE = model,
    MAILLAGE = mesh0,
    AFFE = (
        _F(
            TOUT = 'OUI',
            NOM_CMP = ('X1', 'X2'),
            VALE_F = (f_square, f_signSq)
        )
    )
)

vite = CREA_CHAMP(
    TYPE_CHAM = 'NOEU_NEUT_R',
    OPERATION = 'EVAL',
    CHAM_F = vite_fun,
    CHAM_PARA = vite_ch
)

res_Vite = CREA_RESU(
    OPERATION = 'AFFE',
    TYPE_RESU = 'EVOL_ELAS',
    NOM_CHAM = 'UT01_NOEU',
    AFFE = (
        _F(
            CHAM_GD = vite,
            INST = 0
        )
    )
)

#15 Re: Salome-Meca usage » What model for axialy loaded euler bernoulli beam? » 2020-10-23 00:47:00

Hi JonasA,

You should use, in theory, the POU_D_T_GD element, which is the Timoshenko element that works for large rotations/large displacements, so that you can have the catenary effect you are looking for, see document U3.11.05.

But in practice this element is known to have convergence issues, it is not robust, see for example in the forum these topics:
h ttps://code-aster.org/forum2/viewtopic.php?id=21253
h ttps://code-aster.org/forum2/viewtopic.php?id=23652

#17 Re: Introduce yourself / Présentez vous » Hello from US - wind foundations » 2020-10-15 19:02:26

Hi Kirk,

I had created a wiki-page a few months ago with links for learning material for Code_aster, which can be useful to you.
h ttps://wiki.osarch.org/index.php?title=Learning_Material_for_Code_Aster_and_Salome_Meca

I think you have to start with the book of Aubrey or with some simple tutorials (preferably those that provide also example files) and take it from there.
A simple slab with a point load does not sound so dramatic, but the learning curve in Code_Aster initially is very very steep.

Best,
Ioannis

#18 Re: Code_Aster usage » [SOLVED] CALC_CHAMP and POST_CHAMP in COQUE » 2020-10-14 15:41:10

Hi Massimo,

I don't know the answer to your question, but I would think that the stresses are extracted in the coordinate system of the generalized forces, thus, the one in AFFE_CARA_ELEM.

But I believe these cases are the perfect cases where the user should investigate and test what the software does. Even if you get an answer, you would not want to be sure, yourself, that it does what you expect it to do?

So, in your shoes, I would do a simple cantilever shell with element orientation, for example, perpendicular to bending and a layer orientation of 90 degrees with respect to the element orientation. So that you expect that one of sigma_X and sigma_Y to be zero and the other to be the bending stress.

Then, you can also let us know smile

#20 Re: Code_Aster usage » Time-history analysis how to? » 2020-10-11 12:03:10

Hi GPSalachs,

If you are referring to dyna_non_line and thus want to do a nonlinear analysis, you do not really need the steps of matrix definition necessarily, you may need them to help define modal damping but otherwise no need for stiffness and mass matrix.

In my depository --> h ttps://github.com/Jesusbill/code-aster-examples/ <-- you can find an example with dyna_non_line (Tensegrity Structure Seismic Example) that contains all the steps including a first analysis to apply the gravity loads, and an example with dyna_vibra (LDA Example) that shows how to load and apply txt files with the acceleration time histories (single support).

I hope these can help.

#21 Re: Code_Aster usage » [Solved] Thermo-Elastic analysis » 2020-10-11 00:00:57

Hi tpa,

Yes AFFE_VARC is what should be used to "load" your thermal results into the materials of the mechanical analysis (AFFE_VARC is defined in AFFE_MATERIAU). Also, I would suggest that you use a first order mesh for thermal and a second order mesh for mechanical, otherwise you cannot correctly represent the linear temperature (strain) fields that result in quadratic displacement fields. For this latter step you would need to use PROJ_CHAMP to project fields, but it could be done as a refinement of your study as well.

You can find a worked-out example and accompanying videos that explain the steps at h ttps://github.com/Jesusbill/code-aster-examples - tutorials 4-6.

#22 Re: Code_Aster usage » command MACR_LIGN_COUPE » 2020-06-22 10:29:58

I do not think you need POST_RELEVE_T here. Try directly with IMPR_TABLE with the result from MACR_LIGN_COUPE

#23 Re: Code_Aster usage » Use of COMB_SISM_MODAL for Spectral modal seismic analysis » 2019-09-14 15:11:05

Hi,

Spectral analysis is a bit complicated and you definitely have to read well the documentation to understand the different options but this block of code could help you set up the steps. I use DEFI_FONCTION to define the spectrum by input values directly. Keep in mind that your final spectrum is defined with DEFI_NAPPE, as code_aster calculates the spectra value for each mode based on the specific damping of this mode. So you can define more that one spectra, each one for a specific damping. Of course for typical structural engineering this approach may look unfamiliar because the damping of the structure is considered as a single value and as such a single spectrum is used but nevertheless the use of DEFI_NAPPE, which is for bi-dimensional functions, is mandatory.

    SPEC_H = DEFI_FONCTION(NOM_PARA = 'FREQ',
                          VALE = SpecHor,
                          # VALE = (
                            # 1.0, AccelOfGravity*1.,
                            # 1000., AccelOfGravity*1.,
                          # ),
                          PROL_DROITE = 'CONSTANT',
                          # INTERPOL = 'LOG',
                          )
    
    SPECTRUM = DEFI_NAPPE(NOM_PARA = 'AMOR',
                          PARA = 0.05,
                          # INTERPOL = 'LOG',
                          FONCTION = SPEC_H,)
    
    
    RES_RSA = COMB_SISM_MODAL(MODE_MECA = MODES,
                        AMOR_REDUIT = 0.05,
                        MONO_APPUI = 'OUI',
                        EXCIT = _F(
                                # SINGLE SPECTRUM IN ONE DIRECTION
                                # AXE = (1., 1., 0.),
                                # SPEC_OSCI = SPECTRUM,
                                # ECHELLE = 1.,
                                #
                                # SINGLE SPECTRUM IN TWO DIRECTIONS
                                TRI_AXE = (1. , 0.3, 0),
                                SPEC_OSCI = SPECTRUM,
                                ECHELLE = 1.,
                                #
                                # TRIPLE SPECTRUM
                                # TRI_SPEC = 'OUI',
                                # SPEC_OSCI = (SPECTRUM, SPECTRUM, SPECTRUM),
                                # ECHELLE = (-3. , 1., 0.),
                                ),
                        COMB_MODE = _F(TYPE = 'CQC', # 'CQC' 'SRSS'
                                ),
                        COMB_DIRECTION = _F(TYPE = 'QUAD',
                                ),
                        OPTION = ('DEPL', 'ACCE_ABSOLU', 'SIEF_ELGA', 'SIGM_ELNO', 'EFGE_ELNO', ),
                        )

#24 Re: Code_Aster usage » use of DYNA_VISCO for DISCRET element » 2019-09-05 15:36:11

Hi again,
I am quite sure that discrete elements are not affiliated to materials so MATER_ELAS_FO in DYNA_VISCO should not point to a discrete element. Maybe you can try to use a bar (BARRE maybe) or a beam (POU_D_E) element that is coherent with the line geometry that you use for spring. I would see that more probable.
- ioannis

#25 Re: Code_Aster usage » use of DYNA_VISCO for DISCRET element » 2019-08-31 20:56:45

Hi,

I see some problems in your comm file just by looking at it, I did not download anything.
In any case the spring should be of 'K_T_D_L' type not 'M_T_D_L'. (K for stiffness as oppose to M for mass)
Also the spring element has no material associated so you cannot set a value of 0 in 'K_T_D_L' and then try to assign a material to it. You should create a cylinder or something similar (a volumetric geometry for 3D or an area for 2D) if you want to assign a material with properties with function of frequency.

These are some general comments, I have not ever done this kind of analysis you are looking into.