[Gmsh] meshing multiple objects

Felix Wolfheimer f.wolfheimer at online.de
Sat Nov 15 19:07:59 CET 2008


Dear Christophe,

thank you for the quick reply. The two (or more) solids model objects with
different material properties. Thus, I want to create a mesh that is
conformal to the material interface, such that a tetrahedron of the
generated mesh is located entirely in solid 1 or in solid 2 and,
additionally, the tetrahedrons at the interface region (the face where the
two solids touch) should share a common face. That is, the material
interface should be handled somehow as a single face shared by both solids. 
However, in the file generated by the solid modeler the two solids are two
independent objects and, thus, the mesh is created independently for each of
the objects. It would be nice to know, if there is any easy way to modify
the step or iges file, such that a mesh with the properties described above
is created. Is there any option in gmsh which would allow the creation of
such a mesh directly from the step or iges file?

Please find the file test.stp, which contains a very simple model of two
bricks where the one brick has been trimmed by the other.

Thanks and best regards

Felix 

-----Ursprüngliche Nachricht-----
Von: Christophe Geuzaine [mailto:cgeuzaine at ulg.ac.be] 
Gesendet: Mittwoch, 12. November 2008 20:00
An: Felix Wolfheimer
Cc: gmsh at geuz.org
Betreff: Re: [Gmsh] meshing multiple objects

Felix Wolfheimer wrote:
> Hi Gmsh Experts,
> 
>  
> 
> I would like to create a tetrahedral mesh from iges or step models. The 
> models contain parts which touch each other (result of Boolean 
> operations). However, when I read the model with gmsh the interface 
> region where the solids touch is meshed twice (once for the first object 
> and once for the second). Additionally, the tetrahedrons at the 
> interface overlap arbitrarily. Is there any way to read a CAD model and 
> mesh it with gmsh such that the surface of the interface region of the 
> two solids is meshed only once?
> 

You have to make sure that the solid modeler creates the correct 
geometry for the intersecting objects (intersection curves, etc.)

Can you send the step file?



>  
> 
> Best regards
> 
>  
> 
> Felix
> 
>  
> 
> PS: The screenshot enclosed to this mail may show you the result I get 
> when I try to mesh two cylinders, where the first cylinder was trimmed 
> by the second one.
> 
>  
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh


-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test.stp
Type: application/octet-stream
Size: 22368 bytes
Desc: not available
URL: <http://www.geuz.org/pipermail/gmsh/attachments/20081115/a1dd6893/attachment.stp>