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

You are not logged in.

#1 Re: Code_Aster usage » Aster 101 Examples » 2011-07-29 19:32:34

Hi Ashraf,
I understand your frustration. I used to work for a company that used Code_Aster  as there structural solver. In US no other companies I know use these code. The example was to get something going for code aster… but it seems the people from EDF have the good stuff and every on else has very little knowledge about this code. I was running the example on version 9.2 I believe in windows.  If you want I can give you the windows version…
I highly recommend using NASTRAN, Code_Aster needs more English Documentation and Examples to get ahead which are not available.  Also for high non-linear Ls-dyna will do the job.

#2 Code_Aster usage » Aster 101 Examples » 2010-03-10 18:41:20

Replies: 3

Hi all,

When I started working with Code_Aster, I have noticed a missing element on advancing the group knowledge as a team, and that is solved examples.

I will make a contribution as a start, I will appreciate if all members can add one solved example as contribution to expand everyone’s knowledge about the tool and give a good feedback to the EDF team about potential issues.

The example below will demonstrate how to get the displacements and nodal stresses on a circular plate with clamped boundaries on the outer edge. All files are posted along with the exact solution.

Best regards,
Ahmad Abbas

#3 Code_Aster usage » Simulating natural frequencies in code aster? » 2010-02-26 09:14:51

Replies: 1

Dear all,
Could anyone provide an example for natural frequency simulation in Code_aster? Or send a link to an example, I just need an example for concept, a beam or a shell plate or any simple geometry will do the job.
Thank you in advance for any help,
Ahmad Abbas

#4 Re: Code_Aster usage » [solved] are rigid bodies or rigid links available in Code_Aster? » 2010-02-26 09:02:53

Dear Pierre,
Ok, the RBE element will allow you to create a relationship between two set of elements so they are always fixed in relation to each other and flexible in globally.
  Let say that I have Element 1 and Element 2, {Dx1-Dx2=0, Dy1-DXy=0, Dz1-Dz2=0, drx1-drx2=0, dry1-dry2=0, drz1-drz2=0}, so they translate and rotate together.

Yet RBE2 is little more complicated, let’s assume that we need to simulate a distributed force by a driver hand in a steering wheel. The elements under the drivers hands are the place we need to apply the load to, thus we can use RBE2 or RBE3.

If RBE2 (true rigid element) there will be one node that the force will be applied to and the rest nodes in the RBE2  will experience the load in relative term. The problem with RBE2 is that it will add additional stiffness to the structure.

See pic..............

To avoid the added stiffness we can use RBE3 element – Interpolation Constraint Elements for example in this case RBE3 were used to apply the load to the 12 o’clock position of the rim. This will have a great advantage over using the point load on one node or RBE2, and represent an enhanced model, since RBE3 element great way for distributing applied loads in this model. The RBE3 doesn’t add additional stiffness to the structure. Forces and moments applied to reference points are distributed to a set of independent degrees of freedom based on the RBE3 geometry and local weight factors.   

See Pic ..................

( example from Rim-Roll Flex Test

This test simulates the behavior of steering wheel subjected to repeated driver’s pushing force. The steering wheel is mounted on a rotating fixture with a dead weight roller resting on the rim. It must survive a number of rotations without fracturing or deflecting more that a specified amount depending on the vehicle manufacturer’s requirements.)

Ahmad Abbas

#5 Re: Code_Aster usage » [solved] are rigid bodies or rigid links available in Code_Aster? » 2010-02-17 17:26:16

I just like to add a comment to this conversation, LIAISON_SOLIDE is actually an RBE element yet one needs to understand that it works like a RBE1 (Rigid body connected to an arbitrary number of grid points) and we don’t have the option to use RBE2 (Rigid body with independent DOFs at a grid point and dependent DOFs at an arbitrary number of grid points) in aster. Furthermore, one should not assume high E value in his/her simulation for RBEs because it will act as an RBER element (Rigid bar element).
Ahmad Abbas

#6 Re: Code_Aster usage » [SOLVED] “ENER_ELAS” Error » 2010-02-05 17:51:55

Dear Thomas DE SOZA,

Thank you for your help, I work for a company that will allow us only to use Windows based software. I think having the 9.1 ASTER is better than nothing:). I and my team are interested to compile higher version of Aster for Windows OS, if anyone could help us with any guidelines or advice in how that could be done that would be great. 

I think having that on Windows will increase the number of users and expand the application usage examples and discussion on the forums.  We are currently using Aster 9.1 for windows compiled by NECS http://www.necs.fr

About the energy density issue, since I couldn’t solve the problem by using 9.1 Aster then a manual post processing could be used.
Element used: DKT (shell theory) 

By calculating:
Will get:  SIXX         SIYY         SIZZ         SIXY         SIXZ         SIYZ (for each node)

And by calculating:
We will get:  EPXX         EPYY         EPZZ         EPXY         EPXZ         EPYZ (for each node)

Then the equation for the strain energy density [J/M^3] would be:

U=.5[sigma1^2+Sigma2^2+Sigma3^2 -2v (Sigma2*sigma3+Sigma3*Sigma1+Sigma1*Sigma2)]

Where Sigma1, Sigma2, Sigma3 are the principal stresses and v is the possion’s ratio

That could be written as:


With the unit of J/M^3 .

Ahmad Abbas

#7 Re: Code_Aster usage » Welds in Aster » 2010-01-21 23:21:32

Thank you all for your responses,
If it is not as easy to create welded joints; I was thinking that we could evaluate the added stiffness of
the welded edge on the overall model by creating different properties for the edge line (thickness,
material properties). See image as attached:
I am using shell elements for my model (DKT elements), and that doesn’t allow me to have thickness for
the line. Is there any kind of element that I can use to account for that added stiffness?
Thank you for your assistant and inputs in advance,
Ahmad Abbas

#8 Code_Aster usage » Applying velocity/acceleration dependent pressure "?" » 2010-01-12 17:03:23

Replies: 0

Hello all,
In Code_Aster can one apply a force or pressure as a function of displacement or velocity or
I would like to apply a pressure as a function of X or X| or X||.
For instance: P= P0 – constant*X| for each shell element.
Where p0 is some constant pressure.

#9 Re: Code_Aster usage » [SOLVED] Error "cham_elem etendu a faire ... " » 2010-01-12 15:24:55

It seems like a memory issue, because I did everything the same with the same geometry but a coarser mesh and it ran fine!? .
Thank you,

#10 Code_Aster usage » [SOLVED] Error "cham_elem etendu a faire ... " » 2010-01-05 18:26:58

Replies: 2

Hello all,
I got this error massage; any one knows what it means?
#  ---------------------------------------------------------------------------
    #  COMMANDE NO :  0004            CONCEPT DE TYPE : evol_noli
    #  -------------                  -----------------
   Solver=DYNA_NON_LINE(reuse = Solver,

--- NOMBRE TOTAL DE NOEUDS :        54107  DONT :        41928
--- NOMBRE TOTAL D'EQUATIONS :       115002


INSTANT DE CALCUL :  7.000000000E-03

|   ITERATIONS   |     RESIDU     |     RESIDU     |     OPTION     |
|     NEWTON     |     RELATIF    |     ABSOLU     |   ASSEMBLAGE   |
|                | RESI_GLOB_RELA | RESI_GLOB_MAXI |                |
   ! <F> <CALCULEL2_51>                         !
   !                                            !
   !                                            !
   !  cham_elem etendu a faire ...              !
   !                                            !
   !                                            !
   !                                            !
   ! Cette erreur est fatale. Le code s'arrete. !

Thank you,

Ahmad Abbas

#11 Re: Code_Aster usage » Advance fracture mechanics problems using XFEM » 2009-11-22 21:20:38

I have recently started using Code_Aster and really didn’t know that Aster could do XFEM. When I saw your posting  I was very interested and did a quick search for the XFEM modeling in Aster. I have found the following online:

“The X-FEM allows to introduce a crack in a sound structure. It is implemented in Code_Aster for several years and began to be used in the engineering of EDF in the analysis of toxicity of default.

The definition of the crack is not through the mesh structure, but the calculation of two level sets: a level set normal to locate the surface crack and a level set tangent to locate the bottom crack. Thus, the simulation of crack propagation is equivalent to simulate the spread of the two level sets.

The new order allows PROPA_FISS to propagate a crack 3d any calculations by successive new level sets by projection on the new discretized geometry of the crack. PROPA_FISS need to have the predetermined values of intensity factors of stress at each point of the bottom crack. In 2d, the results are very satisfactory. In 3d, this method still faces difficulties in propagation of off-plan.”
http://www.code-aster.org/V2/doc/v9/man … .82.11.pdf

I think what this is saying is that they have a good model for shell elements and under progress (working) for 3d element types. I really could make use of fracture failure modeling in my current work, thus if anyone has an example your help will be appreciated. 

Thank you,
Ahmad Abbas

#12 Re: Code_Aster usage » [SOLVED] “ENER_ELAS” Error » 2009-11-17 18:32:28

Hello all,

Can anyone guide me to an example where elastic deformation energy Eel or total deformation energy ET =Eel +Epl is solved?
From my understanding, I have to use POST_ELEM, yet the documentation says that the ENER_ELAS is calculated from “SIEF_ELGA ou SIEF_ELGA_DEPL”. I really don’t know how to put the commands together to output the elastic deformation energy.

1. Could someone explain what do, I need to output “ENER_ELAS” or “ENER_TOTALE”?
2. How could one output and  write the result when I use “POST_ELEM”?

Thank you for any help,

A. Abbas

#13 Re: Code_Aster usage » [SOLVED] “ENER_ELAS” Error » 2009-11-10 18:37:29

Thank you for your response, I have not changed the TOUT='OUI' in many places to “GROUP_MA” yet I don’t know what I am doing wrong in regards of calculating the elastic energy on the deforming plate. I basically need to know how to use “Post ELEM” to calculate “ENER_ELAS”. 
•    1x1 m plate steel plate
•    Thickness .01 m
•    Boundary, clamed at all edges at the line.
•    Pressure, uniform pressure on the plate.
So, I understand that by using:
mesh=DEFI_GROUP(reuse =mesh,
mesh=MODI_MAILLAGE(reuse =mesh,
Static=CALC_ELEM(reuse =Static,
Static=CALC_NO(reuse =Static,
I we will get the Equivalent nodal stress and other important results like the strain tensor, yet how could I get the elastic energy, can I use:

If yes, I am getting an error, please note Group”15” is the fixed line in the side and Group”500” is the plate: I get the error:

   ! <F> <CALCULEL_34>                                                        !
   !  le calcul de l'option :  ENER_ELAS  n'est possible pour aucun des types !
   ! d'elements  du ligrel.                                                   !
   ! Cette erreur est fatale. Le code s'arrete.                               !
Please also how do I write the energy to the result file?

Thank you in advance for any help,
A.    Abbas

#14 Re: Code_Aster usage » Modeling elastic_ plastic shell elements with large strains » 2009-11-04 17:56:52

Hello Jacopo,

Thank you for the response, I see that this works great in static case and the results I get are correct. (Compared to classic hand calculation that estimates the displacement and stress)

I am posting the files for static case for anyone who might be interested to learn how to do elastic-plastic deformation of plate using 3-noded DKT element.

Yet when I calculate this in the dynamic case it takes a longgggg time to converge, any Ideas why? Same plate 5 bars uniform pressure with 10ms takes hours to calculate….

                      INTERVALLE=_F(JUSQU_A=(10 * Time),



Thank you,
A.    Abbas

#15 Code_Aster usage » [SOLVED] “ENER_ELAS” Error » 2009-11-04 17:40:02

Replies: 5

Hello all,

I am not sure what I am doing wrong, yet I am trying to calculate “ENER_ELAS” in a simple 1X1 m steel plate subjected to 1bar of uniform pressure.

I get the following error:

! <F> <CALCULEL_34>                                                        !
   !  le calcul de l'option :  ENER_ELAS  n'est possible pour aucun des types !
   ! d'elements  du ligrel.                                                   !
   ! Cette erreur est fatale. Le code s'arrete.                               !

I am using “ENER_ELAS” in POST_ELEM and as far as I understand I need to calculate both 'ENEL_ELGA','ENEL_ELNO_ELGA' in “CALC_ELEM to do that.

How can I get “ENER_ELAS”?
How do I write in my results?

Thank you in advance for any help.
A.    Abbas

#16 Code_Aster usage » Modeling elastic_ plastic shell elements with large strains » 2009-10-29 00:24:28

Replies: 5

Modelisation du comportement elasto-plastique en theorie des coques

Hi All,
I am trying to model large strain/deformation with a “COQUE” elements using elast-plastic model, I have read many of the documentations and posting on the forums. I am still not clear how that is being done in ASTER. If anyone can answer any of the following question, it would be great:
1.    Is it at all possible?
2.    What element types “COQUE” are allowed?
3.    What Deformation model should be used? Is it “DEFORMATION='SIMO_MIEHE'”?
4.    Also what are the main thing to account for with such analysis?

Thank you in advance for any input,
A.    Abbas

#17 Re: Code_Aster usage » necking at a tensile bar » 2009-10-28 23:32:21

Hi all,
I am trying to understand the elasto-plastic molding in Aster. My final goal is to model large strain with either DKT or Coque-3D. Yet I have failed to model that until now.
According to posting:
“lf you have to modelize large strains, then (with DEFORMATION='SIMO_MIEHE') stress-strain curve is the true one : cauchy stress and logarithmic strains. The when you compute the stesses (with STAT_NON_LINE) they are Caychy stresses, and the strains (with CALC_ELEM) are computes with the hypothesis of large strains. “

I have remodeled and ran a simple specimen, yet when I just get little above the yield point my solution diverges and I cannot solve the problem!

INSTANT DE CALCUL :  1.000000000E-01

|   ITERATIONS   |     RESIDU     |     RESIDU     |     OPTION     |
|     NEWTON     |     RELATIF    |     ABSOLU     |   ASSEMBLAGE   |
|                | RESI_GLOB_RELA | RESI_GLOB_MAXI |                |
|     0        X | 4.86406E-01  X | 1.19943E+05    |TANGENTE        |
|     1        X | 2.54900E+00  X | 4.39760E+04    |TANGENTE        |
|     2        X | 4.82148E+00  X | 3.87162E+05    |TANGENTE        |


   ! <EXCEPTION> <COMPOR1_9>                                           !
   ! Arret suite à l'échec de l'intégration de la loi de comportement. !

Why is my solution failing for large strain?
Why I am seeing no necking at all?
Why the user in the posted example used the engineering stress-strain curve? Shouldn’t the strain be in terms of true strain?
e = ln(L / Lo)  ~  el = ln (1+e)   
Thank you in advance for any input,
A.    Abbas

#18 Re: Code_Aster installation » job limited to s » 2009-10-28 15:29:35

Couple month ago I have installed ASTER 9.1 for windows on my Laptop PC (Vista) with no problem and it was working ok, yet I had a problem with my pc so I just simply did the recovery CD thing and on when I reinstalled Aster now I am getting the same error.
I think it’s the X11 server and some server configuration that I don’t know how to setup in vista is causing the problem.
Furthermore, until I know how to fix this I will be using on Vista/XP dual boot, also I think there is a way to integrate the CAELinux with Colinux and windows. If I get this done I will post it in the forums.
A.    Abbas

#19 Re: Code_Aster usage » How display EQUI_ELNO_EPSI on DKT eleemnt in non-linear analysis » 2009-10-26 21:46:57

Ok I think this problem is solved by extra effort from user side in post processing using python or any other code….
When we calculate “EPSI_ELNO_DEPL “ using “CALC_ELEM”  for example we get:

NUMERO D'ORDRE: 1 INST:  1.00000E-01                                           
M158      EPXX         EPYY         EPZZ         EPXY         EPXZ         EPYZ       
N294      1.15881E-05  3.86876E-05  0.00000E+00 -3.08932E-05 -4.37125E-06  3.50328E-06
N155     -1.94818E-20  4.11023E-05  0.00000E+00 -4.62066E-06 -4.37125E-06  3.50328E-06
N156      6.56451E-21 -8.15851E-07  0.00000E+00  2.80464E-06 -4.37125E-06  3.50328E-06

Then by using “CALC_NO” and calculating “EPSI_NOEU_DEPL “we will get for example:
NOEUD        EPXX         EPYY         EPZZ         EPXY         EPXZ         EPYZ   
N1       -1.07706E-06 -1.85632E-06  0.00000E+00 -1.49834E-06  1.31977E-06  3.82515E-07
o   EPXX = EPSX = X Normal strain
o   EPYY =EPSY = Y Normal strain
o   EPZZ= EPSZ = Z Normal strain
o    EPXY= GMXY = Shear strain in Y direction on YZ plane
o   EPXZ= GMXZ = Shear strain in Z direction on YZ plane
o    EPYZ= GMYZ = Shear strain in Z direction on XZ plane
o    ESTRN = Equivalent nodal strain
A.    Abbas

#20 Re: Code_Aster usage » How display EQUI_ELNO_EPSI on DKT eleemnt in non-linear analysis » 2009-10-24 23:57:47


Based on the documentations ‘EQUI_ELNO_EPSI’ is not available of any “COQUE” shell model.

Yet I think by having ‘EPSI_ELNO_DEPL’ one can calculate the strain tensor
(Hopefully) and thus the equivalent strain could be calculated:

o    EPSX = X Normal strain
o    EPSY = Y Normal strain
o    EPSZ = Z Normal strain
o    GMXY = Shear strain in Y direction on YZ plane
o    GMXZ = Shear strain in Z direction on YZ plane
o    GMYZ = Shear strain in Z direction on XZ plane
o    ESTRN = Equivalent strain

Equivalent strain (ESTRN) is defined as:
ESTRN=2 [(e1+e2)/3] (1/2)
e1 = 0.5 [(EPSX-e*)2 + (EPSY-e*)2 + (EPSZ-e*)2],
e2 = 0.5 [(GMXY)2 + (GMXZ)2 + (GMYZ)2] / 4,
e* = (EPSX + EPSY + EPSZ) / 3

Yet I have not done that before in Code_Aster, can any one please tell me how one can find:

o EPSX = X Normal strain
o EPSY = Y Normal strain
o EPSZ = Z Normal strain
o GMXY = Shear strain in Y direction on YZ plane
o GMXZ = Shear strain in Z direction on YZ plane
o GMYZ = Shear strain in Z direction on XZ plane

From “EPSI_ELNO_DEPL” or any other thing in a shell model.

Thank you,
A. Abbas

#21 Re: Code_Aster usage » <F>_ABNORMAL_ABORT exit code = 139 » 2009-10-19 07:16:04

I think I had a similar problem to what I see here, I basically call it Aster is tired smile, I been looking for any reason for this as well, but did not really have anything out of my research. But one thing is known, this problem is some how mesh dependent, by small change in my mesh file the problem sometimes just doesn’t appear anymore or happens in different number of iteration.
A Abbas

#22 Re: Code_Aster usage » Knowledge Trade Code_Aster- Bolts for Welds » 2009-10-19 02:28:54

Thank you for your reply,
Just to clarify; there is no direct solution that Aster provides for handling the bolted or screwed assemblies. So my solution for the bolted assemblies is really an add-on code based on advance mechanical relations that must be conducted to the results file from aster to determine possible failure of the bolts or nuts. Thus, I am not holding any Aster related information.
Thank you,

#24 Code_Aster usage » Knowledge Trade Code_Aster- Bolts for Welds » 2009-10-09 17:17:46

Replies: 3

Hello all,

I have noticed none of EDF guys have the time or the well to help in defining how to account for welded surfaces/plates in Code_Aster. I have read some documents that insured me there is a way to define weld between two plates. I have spent lots of time reading in finding how to define bolted assemblies in shell models and 3D models. I saw that many people have asked about bolted assemblies on the forums; yet no one answered them.
The deal:
If anyone can tell me how to define welded assemblies in Code_Aster , I will send him/her full instruction and solved examples for shell/plates bolted assemblies and 3D bolted assemblies.

Thank you in advance for any help.

#25 Code_Aster usage » Welds in Aster » 2009-09-28 14:47:41

Replies: 6

Hello every one,
Thank you for your input and views of my previous posting on the Aster forum; I have a very general question.

1.    Is there any way to model a simple welded joint between shell element or 3d  elements like:

((see image))
What would be the definition of the connectivity and the new element properties?
2.    Can I use AFFE_CHAR_MECA>>
      Is that really a weld? What type? What are the thickness, angles, layers….