Welcome to the forums. Please post in English or French.

You are not logged in.

#1 Re: Code_Aster usage » [solved] reading rmed file for post processing » 2019-10-17 04:24:30

Thanks. I could do the calculation.
For completeness, i post here the steps.
#1. Read the old result.rmed file by LIRE_MAILLAGE
#2. Use LIRE_RESU to result result variable (you should know the result variable)
#3. Define same material properties and assign to model and also while using CALC_CHAMP
------

mesh = LIRE_MAILLAGE(FORMAT='MED',
                     UNITE=20)

model = AFFE_MODELE(AFFE=_F(MODELISATION=('3D', ),
                            PHENOMENE='MECANIQUE',
                            TOUT='OUI'),
                    MAILLAGE=mesh)

steel = DEFI_MATER_GC(ACIER=_F(D_SIGM_EPSI=10000000000.0,
                               E=2e+11,
                               NU=0.3,
                               SY=400000000.0),
                      RHO=7850.0)

conMazMa = DEFI_MATERIAU(ELAS=_F(E=37303280300.0,
                                 NU=0.2,
                                 RHO=2400.0),
                         MAZARS=_F(AC=1.26865552,
                                   AT=0.9,
                                   BC=1681.54688,
                                   BT=12688.1906,
                                   EPSD0=7.88134441e-05,
                                   K=0.7,
                                   SIGM_LIM=39000000.0))

fieldmat = AFFE_MATERIAU(AFFE=(_F(GROUP_MA=('group_concrete', ),
                                  MATER=(conMazMa, )),
                               _F(GROUP_MA=('group_mainrebar', 'group_shearrebars'),
                                  MATER=(steel, ))),
                         MAILLAGE=mesh,
                         MODELE=model)

oldres = LIRE_RESU(FORMAT='MED',
                   FORMAT_MED=_F(NOM_CHAM='DEPL',
                                 NOM_RESU='resnonl0'),
                   MODELE=model,
                   TOUT_ORDRE='OUI',
                   TYPE_RESU='MODE_MECA',
                   UNITE=20)

stress = CALC_CHAMP(CHAM_MATER=fieldmat,
                    CONTRAINTE=('SIGM_ELNO', ),
                    DEFORMATION=('EPSI_ELNO', ),
                    MODELE=model,
                    RESULTAT=oldres)

IMPR_RESU(FORMAT='MED',
          RESU=_F(RESULTAT=stress),
          UNITE=80)

#2 Code_Aster usage » What does STOP_SINGULIER does? » 2019-10-16 05:07:04

nirmaljoshi
Replies: 0

When node numbers are huge and number of boundary nodes are small, code aster spits out "Singularity ERROR or near singular error" and saying some loss in precesion. But during analysis if i check off STOP_SINGULIER there is no error. Can anyone explain what is the cause of this error and why there is no error when i check off? What is nearly singular case?

#3 Re: Code_Aster usage » How to add a nonlinear behaviour in STAT_NON_LINE analysis » 2019-10-16 03:56:29

Alessia Bez wrote:

Thank you so much for your answer. You confirmed what I imagined, but is this the only way to consider non-linear elastic behavior? I would like to insert a constitutive law obtained from laboratory tests to describe the behavior of a particular material, do you think it is possible?

For that case, you can define function for the material properties (copied from book by jean)
e.g.

s235elpl=DEFI_FONCTION(
NOM_PARA=’EPSI’ ,NOM_RESU=’SIGMA’ ,
VALE=(
#there should not be a point at 0.0, 0.0
#0.0000, 0.0
0 . 0 0 1 1 4 , 2 4 0 . 0 ,
0 . 0 0 1 2 , 2 4 1 . 0 ,
0 . 0 0 2 0 , 2 4 1 . 6 ,
0 . 0 0 5 0 , 2 4 4 . 0 ,
0 . 0 1 0 0 , 2 4 8 . 0 ,
0 . 0 1 5 0 , 2 5 2 . 0 ,
0 . 0 5 0 0 , 2 8 0 . 0 ,
0 . 1 0 0 0 , 3 2 0 . 0 ,
0 . 1 5 0 0 , 3 6 0 . 0 ,
0 . 2 0 0 0 , 3 8 0 . 0 ,
0 . 4 0 0 0 , 4 2 0 . 0 ,
) ,
INTERPOL=’LIN’ ,
PROL_DROITE=’LINEAIRE’ ,
PROL_GAUCHE=’CONSTANT’ ,
) ;

and define the material and apply it

steel=DEFI_MATERIAU(
ELAS=_F(E=210000 ,NU = 0 . 3 , ) ,
TRACTION=_F(SIGM=s235elpl , ) ,
) ;
mate=AFFE_MATERIAU(
MAILLAGE=mesh1 ,
AFFE=_F(TOUT=’OUI’ ,MATER=steel , ) ,
) ;

and perform analysis


resunl=STAT_NON_LINE(
MODELE=mod1 ,
CHAM_MATER=mate ,
EXCIT=(
_F(CHARGE=fix1 , ) ,
_F(CHARGE=load , TYPE_CHARGE=’FIXE_CSTE’ ,FONC_MULT=load_m , ) ,
) ,
COMPORTEMENT=_F(
RELATION=’VMIS_ISOT_TRAC’ , #U4.51.11 para 4.3.1.3
DEFORMATION=’SIMO_MIEHE’ , #U4.51.11 para 4.5.3
) ,
INCREMENT=_F(LIST_INST=linst , ) ,
NEWTON=_F(
PREDICTION=’TANGENTE’ ,
MATRICE=’TANGENTE’ ,
REAC_ITER=1 ,
) ,
CONVERGENCE=_F(RESI_GLOB_RELA=1e?4,ITER_GLOB_MAXI=3 0 0 , ) ,
) ;

#4 Code_Aster usage » [solved] reading rmed file for post processing » 2019-10-16 02:49:24

nirmaljoshi
Replies: 2

Hi,
Which command should i use to read result.rmed file (created after very long processing time) so that i can post process it (CALC_CHAMP) without re-running the analysis. In the previous analysis i forgot to calculate SIGM_ELNO and the hdf file has broken. I only have the mesh file and "rmed", the result file.

The CREA_RESU has no option to read external files.

Please help.

#5 Re: Code_Aster usage » select nodes of quadratic mesh » 2019-09-25 03:31:05

@Konyaro: Thanks a lot. I got the idea.

@jeanpierreaubry: I will test and post it here. The reaction forces values were correct when i used linear mesh but it showed error when i switched to quadratic mesh.

#6 Code_Aster usage » select nodes of quadratic mesh » 2019-09-24 08:42:39

nirmaljoshi
Replies: 3

In salome meca I could not find way to make a group of mesh to select all nodes of quadratic mesh (face). Has this to be done in code-aster itself? If so how? I need it to extract the reaction forces from the nodes.

#7 Re: Code_Aster usage » varying E with time using ELAS_FO » 2019-09-04 04:34:35

Dear Manon,
Thanks for pointing towards correct direction.

Using ELNO_NEUT_F field prevented that error. But now i get error saying "only the fields of functions to the nodes are appraisable: CHAMP_ELEM_NEUT_F" while i invoke CREA_RESU using the field created by the CREA_CHAMP.

When I use NOEU_NEUT_F, the error disappears, but again, there is no effect on the elasticity and i get constant displacement (file attached).

I am stucked!

#8 Re: Code_Aster usage » varying E with time using ELAS_FO » 2019-09-03 05:54:30

It seems in CREA_CHAMP (AFFE=_F(.. VALE=(365)) is causing the calculation to give constant displacement.  When I try to use VALE_F=somefunction, it gives error saying "inconsistency between component count and many values".

So is there any way to change the time within CREA_CHAMP or CREA_RESU?

#9 Code_Aster usage » varying E with time using ELAS_FO » 2019-09-02 10:20:26

nirmaljoshi
Replies: 3

Hi all,
Could you please help me for the following task.

I have to model a concrete prism whose elasticity(E) decreases with time (0 to 365 days). I want to calculate displacement with respect to time for a constant load. 

Using the method mentioned in the posts at forum2/viewtopic.php?id=24091 and forum2/viewtopic.php?id=20431, I wrote my analysis file. It runs, but there is no evolution of E with time- resulting in constant deformation for all the time steps.

What am I missing? Please help. File is attached.

#10 Re: Code_Aster usage » documentation of BETON_RAG » 2019-08-28 04:46:24

The validation files such as SSNV400A, SSNV400B also do not work due to syntax error probably due to version difference. Does anyone have the file for new version?

#11 Re: Code_Aster usage » ERROR in documentation » 2019-08-28 04:43:24

Document U4.43.01 DEFI_MATERIAU

Section 7.21 Keyword BETON_RAG
The syntax given below do not match with the code aster/salome meca input. Instead it is something as shown in attached snapshot.


/ BETON_RAG = _F(
Characteristics for the mechanical behavior damage
♦ ENDO_MC = meca_mc [R]
♦ ENDO_MT = meca_mt [R]
♦ ENDO_SIGUC = meca_siguc [R]
♦ ENDO_SIGUT = meca_sigut [R]
♦ ENDO_DRUPRA = will meca_drupra [R]
Characteristics of creep
♦ FLUA_SPH_KR = flua_sph_kr [R]
♦ FLUA_SPH_KI = flua_sph_ki [R]
♦ FLUA_SPH_NR = flua_sph_nr [R]
♦ FLUA_SPH_NI = flua_sph_ni [R]
♦ FLUA_DEV_KR = flua_dev_kr [R]
♦ FLUA_DEV_KI = flua_dev_ki [R]
♦ FLUA_DEV_NR = flua_dev_nr [R]
♦ FLUA_DEV_NI = flua_dev_ni [R]
Characteristics of L has formation of the gels and of the RAG
♦ GEL_ALPHA0 = gel_alpha0 [R]
♦ GEL_TREF = gel_tref [R]
♦ GEL_EAR = gel_ear [R]
♦ GEL_SR0 = gel_sr0 [R]
♦ GEL_VG = gel_vg [R]
♦ GEL_MG = gel_mg [R]
♦ GEL_BG = gel_bg [R]
♦ GEL_A0 = gel_a0 [R]
♦ RAG_EPSI0 = rag_epsi0 [R]
♦ PW_A = pw_a [R]
♦ PW_B = pw_b [R]
)

#12 Re: Code_Aster usage » documentation of BETON_RAG » 2019-08-26 10:29:21

It seems following documents has become accessible now.

[V6.04.214] SSNV214 - Law BETON_RAG behavior: a cyclic loading test of concrete
[V6.04.215] SSNV215 - Law BETON_RAG behavior: test of the main directions of rotation

But the file used in these examples ssnv214.mater.datg and ssnv215.mater.datg are not in the validation folder. If anyone has this file, can you please provide it?

Regards,

#13 Code_Aster usage » documentation of BETON_RAG » 2019-08-26 06:08:01

nirmaljoshi
Replies: 2

The validation/example documents mentioned in section 5 of R7.01.26 BETON_RAG is missing. Also following files are in restrictive access. Does anyone know how to access those files? My research involves this theory hence I want to get access to these files.

[V6.04.212] SSNV212 - Law BETON_RAG behavior: swelling free sample restricted access
[V6.04.213] SSNV213 - Law BETON_RAG behavior: swelling of sample prevented restricted access
[V6.04.214] SSNV214 - Law BETON_RAG behavior: a cyclic loading test of concrete restricted access
[V6.04.215] SSNV215 - Law BETON_RAG behavior: test of the main directions of rotation restricted access
[V6.04.216] SSNV216 - behavior law BETON_RAG: biaxial creep of a cube restricted access

Also the variables mentioned in section 7.21 of U4.43.01 DEFI_MATERIAU are not available in the salome meca window for beton_Rag.

Regards,

#14 Re: Code_Aster usage » [solved]getting started with spring » 2019-06-24 09:49:11

Thanks a lot.
All examples I went through had ASSEMBLAGE while using DST_T so i thought it had to be used. Obviously I was wrong.

Thanks again!

#15 Code_Aster usage » [solved]getting started with spring » 2019-06-24 08:36:50

nirmaljoshi
Replies: 2

Hi, Could you please help me to get started with spring (DST_T) element. I tried with some examples in documentation but could not get on well.  I tried with a single spring with fixed one end and load at the other end (see attachment).

I think  I could not understand how the assemblage works. Could you please explain.

#16 Re: Code_Aster usage » mazars problem » 2019-06-20 11:31:01

jlf wrote:

Hi,

Did you plot the mazars behavior for unidimensional traction and compression with your parameters ?

JLF

How do we do that? Can you provide simple example.

#17 Re: Code_Aster usage » mazars problem » 2019-06-20 11:29:33

Here is worksheet to calculate mazars parameter by yourself.

Also you can use DEFI_MATER_GC so that you do not need to input each parameters.

#18 Re: Code_Aster usage » High-level questions, linear transient analysis with moving BC » 2019-06-04 09:18:16

If this is static analysis, you can write python code that loops to change the code_aster commands with change in boundary node in each step.

#19 Code_Aster usage » how to post process to get cracks in RC concrete? » 2019-06-04 09:11:43

nirmaljoshi
Replies: 3

Hi, how can we calculate and display the crack pattern in RC beam or slabs?

#20 Re: Code_Aster installation » Code Aster Memory and CPU Sharing » 2019-05-23 10:18:09

I am experiencing similar situation.
I have system with 32Gb ram and 12 processors. But CA uses only 2gb ram at max and 2 CPUs during computation.

For the analysis i am running, it takes 2-3 hours of calculation with MULTI_FRONT. There are about 2000 8-noded quads with 5000 steps. I think this is fairly large problem to solve.

..only efficient if you have big linear systems to solve and you're using MULT_FRONT or MUMPS to do that..

So what does it require to be a "big linear system".

How do we set the CA to use most of the resource and compute the solution faster? And more thing i noted was, it takes significant time to write the result to the output files (e.g. med file or txt file).

#21 Salome-Meca usage » issues with HDF files in windows » 2019-05-23 03:36:24

nirmaljoshi
Replies: 0

The HDF files gets reset while i move the folder and I have to recreate the file again. This is more annoying for the geometry module becuse all the data of geometry module is lost when hdf is reset. Generally i export mess and command file but geometry is too troublesome to export (large file size and each component should be exported separately).

Is there any solution?

#22 Re: Code_Aster usage » [solved]help to find error » 2019-05-22 12:47:16

Thanks to all. I was stupid that I did not check the mesh properly before submitting here in the forum. Now everything is working fine.
Now, I have also modified the convergence criteria to required accuracy and the results are promising(i.e. more or less the result is matching with the experiment values). And of-course I have to tweak the parameter in the next step.

The comparison between 1d BARRE and 3d to model the reinforcement steel in a beam was the main objective of this analysis. Attached is the result.

#23 Re: Code_Aster usage » [solved]help to find error » 2019-05-22 07:06:22

Mr. jeanpierreaubry
You are completely missing the point. I repeat.. the issue is - why one analysis runs and another do not run with almost same setting (yes.. the convergence settings are also same in both files).

Since same are the settings, either both files should run, or both files should show error. But only one is working while other is showing error. Hence, the confusion.

#24 Re: Code_Aster usage » [solved]help to find error » 2019-05-22 05:05:03

@jeanpierreaubry
Thank you for providing time to review the analysis files.
Currently, the issue is not the convergence. The issue is that the file in "not-working" folder do not run at all while another file with almost same configuration runs without problem. If we could settle the reason for this behaviour then we can later talk about the convergence issues. Hope for your kind help.

#25 Re: Code_Aster usage » [solved]help to find error » 2019-05-21 11:52:58

Sorry for the mistake.
Here is the zip with both files.