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Split bodies for an assembly

Posted: 23 Jun 2021, 15:52
by jules_guyon
Hi everyone,

I'm working on a capacitance sensor where a flow of water is going through it. I meshed my design (cannot attach the file since it's too big) on Salome meca and exported the mesh in .unv format to import it on Elmer. I tried to select the different bodies in the menu on the left in Elmer but none of the objects (11 Body Properties) colored in red to confirm that i was selecting a body. The only thing that is correctly selected is when i select Boundary 1 (14 Boundaries) and there, every objects on the model is colored in red.

Thus, i'm wondering how to split the model to get the bodies and to be able to select them ?

Because in Salome, i already explode the assembly into coumpounds, made a partition of the assembly, explode the electrodes into faces, created groups of faces for the electrodes' faces before meshing so i thought i had already defined the different bodies.

Thank you in advance for your help :D

Re: Split bodies for an assembly

Posted: 23 Jun 2021, 18:31
by kevinarden
In 3d you put volumes in groups to make bodies, and face elements in groups to make boundaries
In 2d you put faces in groups to make bodies, and edge elements in groups to make boudaries.

In ElmerGUI, 3d the boundary elements are used to display the body. So if there are multiple parents for boundaries, or internal boundaries, ElmerGUI can get a little confused about displaying bodies.

Re: Split bodies for an assembly

Posted: 23 Jun 2021, 19:15
by raback
Hi

When you translate the UNV file into Elmer mesh type using ElmerGrid you get a skeleton for the sif file + names of entities available for defining your case. Maybe this would be easier for you if you already took the effort to group things in Salome.

-Peter

Re: Split bodies for an assembly

Posted: 24 Jun 2021, 17:09
by jules_guyon
Thanks for your responses,

I forgot to mention that in Salome, i created a Group of volumes from geometry selecting all the elements in my partition and then i created a Group of faces from geometry selecting all the faces from the electrodes (where i want to impose my boundary conditions) in my partition.

Despite this, after importing the unv file in Elmer, i had all my body properties and boundaries in the menu on the left but only Boundary 40 colored everything in red in the model when selected and the others didn't colored anything.

I checked the sif as you suggested me but i can only see parameters, variables and constants of simulation and nothing more.

Then, i think the issue comes from Salome but i don't really know where exactly ...

Re: Split bodies for an assembly

Posted: 25 Jun 2021, 13:44
by kevinarden
By skeleton for the sif file + names of entities available for defining your case he means there should have been an entities.sif file created with the mesh files. In the entities.sif file there are the names of bodies and boundaries corresponding to you group names. In salome you should have a group for each boday, and a group for each boundary.

Re: Split bodies for an assembly

Posted: 25 Jun 2021, 15:32
by jules_guyon
Yes yes i know, i openned the sif document on Elmer after generating it and i could only see in this document the parameters, variables and constants.