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Mesh and submeshes to be used in Code aster
- Poddey
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10 years 5 months ago - 10 years 5 months ago #7778
by Poddey
Mesh and submeshes to be used in Code aster was created by Poddey
Hi all,
I made a simple model (see the attached screenshot) in order to test some basic approaches I will need for a more complicated FEM study.
I have a basic box with two circular cuts (similar to the 'hold' holes in the piston tutorial).
On top of the box are two parallel additional boxes.
The goal is to apply a material 'matA' to the main box, a different material 'matB' to the two additional boxes,
apply a certain pressure on the top face of the left additional box and a different pressure on the top face of the right additional box.
The structure should be 'held' by a boundary condition on the holes surfaces (similar to the piston tutorial).
In order to be able to assign different materials in code aster, I need different mesh entities for the box and additional boxes. In addition, the boxes shoould share the face.
I therefore would introduce a partition of additionalBoxLeft and right, and a partition of the result and the main box.
It is however not clear to me how to arrive at different mesh entities usable in code aster sharing the partition interface...
Do I have to use submeshes?
Could someone give me a hint in which sequence I have to apply which meshing function?
Thx
Alex
Edit: I can not upload the screenshot, so here is a link:
http://www.imagesup.net/?di=2141112869013
I made a simple model (see the attached screenshot) in order to test some basic approaches I will need for a more complicated FEM study.
I have a basic box with two circular cuts (similar to the 'hold' holes in the piston tutorial).
On top of the box are two parallel additional boxes.
The goal is to apply a material 'matA' to the main box, a different material 'matB' to the two additional boxes,
apply a certain pressure on the top face of the left additional box and a different pressure on the top face of the right additional box.
The structure should be 'held' by a boundary condition on the holes surfaces (similar to the piston tutorial).
In order to be able to assign different materials in code aster, I need different mesh entities for the box and additional boxes. In addition, the boxes shoould share the face.
I therefore would introduce a partition of additionalBoxLeft and right, and a partition of the result and the main box.
It is however not clear to me how to arrive at different mesh entities usable in code aster sharing the partition interface...
Do I have to use submeshes?
Could someone give me a hint in which sequence I have to apply which meshing function?
Thx
Alex
Edit: I can not upload the screenshot, so here is a link:
http://www.imagesup.net/?di=2141112869013
Last edit: 10 years 5 months ago by Poddey.
- Johannes_ACKVA
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10 years 4 months ago #7784
by Johannes_ACKVA
Replied by Johannes_ACKVA on topic Re: Mesh and submeshes to be used in Code aster
hello Alex,
there are different paths to do this. The most usual is this one:
1) having 3 geometrical solids in Salome Geom Module, create a Compound containing these 3 boxes.
2) Explode the 3 solids (boxes) again out of this Compound. Before doing this, You might inspect the Compound with the command "Mesures - What is" to get insight in what the Compound contains as "SubGeometries"
3) Change to Salome's Mesh Module. Create a Mesh of the Compound (Mesh - CreateMesh)
4) Create 3 groups for the boxes (Mesh - CreateGroup), based on the exploded SubGeometries.
That's it. The boxes don't have common nodes (no connecting interface), because during Meshing of a Compound the Mesher does nothing else than meshing all boxes separately. You should not try to merge the nodes (which is only possilbe if the nodes have the same cooridinates). The easier way to connect the interface is to use the Code-Aster command AFFE_CHAR_MECA(...LIAISON_MAIL (TYPE_RACCORD=SOLIDE), look to the doc or examples in forums, it is widely explained.
In Code-Aster You assign Your different materials to the boxes, assinging it to the groups of elements (which might be named 'box1', 'box2',..):
AFFE_MATERIAU( GROUP_MA='box1', MATERIAU='steel1' ..... GROUP_MA='box2', MATERIAU='steel2'
Use eficas to create the .comm-file. It helps to find out the correct syntax.
Now You need also groups of face elements wrapping around Your boxes. For example a group of the face elements of the top of a box to apply the pressure.
You can do that in the common way in Salome. As You did it with the boxes You must also explode such faces out of Your geometrical compound.
You do not need submeshes in Salome if You wish the same mesh density to all boxes (a unique set of Hypotheses and Algorithms are applied to the Compound).
A SubMesh for a small box might only be useful if You want to apply a different elm size to those elements (create SubMesh with appropriate Hypotheses and Algorithms for the SubGeometry of this box)
I wish You success
Johannes_ACKVA
______________________________________________________________________
CODE-ASTER-courses at Ingenieurbüro für Mechanik, Germany
*** CODE-ASTER INTRO + CONTACT + MATERIAL
5 days, Mon 08 to Fri 12 of Dec 2014
*** CODE-ASTER DYNAMIC ANALYSIS
2 days, Thur 15 to Fri 16 of Jan 2015
*** CODE-ASTER PYTHON
3 days, 25 to 27 of Feb 2015
there are different paths to do this. The most usual is this one:
1) having 3 geometrical solids in Salome Geom Module, create a Compound containing these 3 boxes.
2) Explode the 3 solids (boxes) again out of this Compound. Before doing this, You might inspect the Compound with the command "Mesures - What is" to get insight in what the Compound contains as "SubGeometries"
3) Change to Salome's Mesh Module. Create a Mesh of the Compound (Mesh - CreateMesh)
4) Create 3 groups for the boxes (Mesh - CreateGroup), based on the exploded SubGeometries.
That's it. The boxes don't have common nodes (no connecting interface), because during Meshing of a Compound the Mesher does nothing else than meshing all boxes separately. You should not try to merge the nodes (which is only possilbe if the nodes have the same cooridinates). The easier way to connect the interface is to use the Code-Aster command AFFE_CHAR_MECA(...LIAISON_MAIL (TYPE_RACCORD=SOLIDE), look to the doc or examples in forums, it is widely explained.
In Code-Aster You assign Your different materials to the boxes, assinging it to the groups of elements (which might be named 'box1', 'box2',..):
AFFE_MATERIAU( GROUP_MA='box1', MATERIAU='steel1' ..... GROUP_MA='box2', MATERIAU='steel2'
Use eficas to create the .comm-file. It helps to find out the correct syntax.
Now You need also groups of face elements wrapping around Your boxes. For example a group of the face elements of the top of a box to apply the pressure.
You can do that in the common way in Salome. As You did it with the boxes You must also explode such faces out of Your geometrical compound.
You do not need submeshes in Salome if You wish the same mesh density to all boxes (a unique set of Hypotheses and Algorithms are applied to the Compound).
A SubMesh for a small box might only be useful if You want to apply a different elm size to those elements (create SubMesh with appropriate Hypotheses and Algorithms for the SubGeometry of this box)
I wish You success
Johannes_ACKVA
______________________________________________________________________
CODE-ASTER-courses at Ingenieurbüro für Mechanik, Germany
*** CODE-ASTER INTRO + CONTACT + MATERIAL
5 days, Mon 08 to Fri 12 of Dec 2014
*** CODE-ASTER DYNAMIC ANALYSIS
2 days, Thur 15 to Fri 16 of Jan 2015
*** CODE-ASTER PYTHON
3 days, 25 to 27 of Feb 2015
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