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#1 Re: Code_Aster usage » Stresses expressed in local coordinate system of volume elements? » 2021-08-16 08:50:00

LS

Is there a possibility to obtain stresses of 3D-elements in local coordinate directions?

Like Oltreuomo, I have assigned an orthotropic material to my volume elements and aim to obtain the stresses/displacements in direction of the local coordinates.

#2 Re: Code_Aster usage » Assign & Orient Orthotropic Materials » 2021-08-09 16:19:01

LS

Any suggestions how to assign and orient orthotropic materials?

Many thanks in advance,
Lukas

#3 Code_Aster usage » Assign & Orient Orthotropic Materials » 2021-07-28 09:38:34

LS
Replies: 1

Hi all,

I aim to define a local coordinate system for 3D-elements to assign orthotropic materials. My model is a beam with a 90° bend that is divided into multiple smaller volumes (i.e. groups). Each volume group should have its own local coordinate system. The attached figure should demonstrate the intention.

To correctly assign and orient orthotropic materials I aim to change the local x- and z-axis compared to the global CS; I am looking for something like:

Define local coordinate system:    
        x_axis = Perpendicular to local y and z axis
        y_axis = Global Y axis
        z_axis = Normal to "free" surface of each volume

Is there a command like that in code aster? Or is there a simpler way to assign/orient orthotropic materials?

Any advice is greatly appreciated,,
Lukas

#4 Re: Code_Aster usage » [SOLVED] No Result File Created when Simulating Two Volumes in Contact » 2021-06-22 09:29:37

LS

Hi everyone,

for completeness and further reference I share the solution I found. The attached model is a sandwich beam that shows the method:

The faces I aim to model as shell elements are defined as a group in the geometry module. In the mesh module I define two separate meshes: one for the core volume and one for the shell elements. The groups from geometry module are included in both meshes. By default these groups have the same name in both meshes, you need to rename one of them to later use the liasion mail command in code_aster.

Cyprien Rusu's video "Simulating a contact solid-plate" is a good reference for the liaison mail command.

Best,
Lukas

#5 Re: Code_Aster usage » [SOLVED] No Result File Created when Simulating Two Volumes in Contact » 2021-05-31 15:52:40

LS

Hi all,

I am still struggling to add shell elements to my model. I read numerous topics in this forum and added the liasion mail command.  Nevertheless, I could not obtain a working simulation without any error.

Do you have any suggestions how to make the simulation work? What is the best way to add shell elements to my model?

You find the current model, .comm file, message file and an illustrative figure attached.

Best,
Lukas

#6 Re: Code_Aster usage » [SOLVED] No Result File Created when Simulating Two Volumes in Contact » 2021-05-20 14:57:26

LS

Hi all,

I successfully modeled the two touching hexagonal volumes using  "partition"  in Salome and applied a very simple load case. However, I did not manage to add the shell elements to the top and base of the volumes. The respective areas are marked yellow in the attached figure, this should clarify the purpose. Also I have attached the simplified working model file (hdf and command).

What is the best method to add shell elements to the top/base faces in this case?

@sameer21101970: I am using one mesh for both volumes and believe that Liasion_mail is only used to combine multiple/different meshes, right?

Again, any feedback is greatly appreciated.
Lukas

#7 Re: Code_Aster usage » [SOLVED] No Result File Created when Simulating Two Volumes in Contact » 2021-05-18 11:22:11

LS

Hi AsterO'dactyle,

Many thanks for your reply. Where can I find more exact information for the failure? I am still new to code_aster and cannot find the cause for the error.

Best,
Lukas

#8 Re: Code_Aster usage » [SOLVED] No Result File Created when Simulating Two Volumes in Contact » 2021-05-17 17:42:42

LS

Hi Hanbin,

Many thanks for your reply. Unfortunately your suggestion did not solve the problem and I still get the same error. Do you have any other idea?

Best,
Lukas

#9 Code_Aster usage » [SOLVED] No Result File Created when Simulating Two Volumes in Contact » 2021-05-17 17:24:00

LS
Replies: 9

Hi everyone,

I aim to simulate two hexagonal volumes that have a common face where they are in contact. Both hexagons are sandwich structures and consist of a top & base material modeled as shell elements. The cores of the two hexagons are modeled as volume elements and have different materials (coreMat1, coreMat2).
When I run the simulation the calculation starts, however it breaks and returns the warning:

"<A>_COPYFILE       no such file or directory: fort.3"

I understand that this refers to the missing result file, which is not created. A similar simulation with one hexagon only did run successfully. However, I could not obtain any result for two hexagons in contact. I have attached the relevant files (comm, export, message, med, hdf).

Do you know what could solve the problem?

Any advice is greatly appreciated,
Lukas

#10 Re: Code_Aster usage » Run code_aster Simulation Using Python (in YACS Module) » 2021-05-10 21:12:22

LS

Hi Maggoo,

many thanks for your reply, Cypriens tutorials are great indeed! I did already follow his video to create my YACS/Python model. Since these tutorials are quite popular I thought that someone might encounter the same error or even know how to solve it.

Best regards,
Lukas

#11 Code_Aster usage » Run code_aster Simulation Using Python (in YACS Module) » 2021-05-10 17:07:21

LS
Replies: 2

Hi everyone,

I aim to run a Code_aster simulation using Python in the Salome YACS module (Salome 2020 on Ubuntu 20.04 LTS). To do so I used the Python subprocess function, however when I run the code I obtain an error (see below). I understand that YACS cannot find the as_run file. IMHO the path is correct and should run.

Do you have any idea what the reason for this error might be and what could solve it?

Any advice is greatly appreciated,
Lukas



Error message:

<error node= newSchema_1 state= FAILED>
<error node= asterNode state= ERROR>
Traceback (most recent call last):
  File "/tmp/PythonNode_4144", line 7, in <module>
    proc = subprocess.Popen([os.path.join(appliPath, 'as_run')] + [export], close_fds=True)
  File "/home/lukas/salome_meca/V2020.0.1_universal_universal/prerequisites/Python-365/lib/python3.6/subprocess.py", line 709, in __init__
    restore_signals, start_new_session)
  File "/home/lukas/salome_meca/V2020.0.1_universal_universal/prerequisites/Python-365/lib/python3.6/subprocess.py", line 1344, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: '/home/salome_meca/V2020.0.1_universal_universal/tools/Code_aster_frontend-202001/bin/as_run': '/home/salome_meca/V2020.0.1_universal_universal/tools/Code_aster_frontend-202001/bin/as_run'

</error>
</error>

#12 Introduce yourself / Présentez vous » Hello World! » 2021-05-01 09:52:34

LS
Replies: 0

Hi everyone,

My name is Lukas and I am a master student in mechanical engineering at ETH Zürich, Switzerland. I am still new to FEA and about to explore the benefits of open-source software. For my master thesis I aim to optimize the core of sandwich structures using code_aster.

Cheers