[Gmsh] boolean partitioning

[andrew]

thank you for your reply,

I have found an another way to import a brep file. However I can't
understand how the characteristic sizes are applied. I want to apply a more
dense mesh around the internal surfaces without the cost of a field
command.

However no matter how I apply the internal sizes I can't get a good mesh.
Is there a way to achieve a more dense mesh by using characteristic
commands only?


kind regards

Andrew tsiantis

2017-05-03 0:38 GMT+03:00 Christophe Geuzaine <cgeuzaine at ulg.ac.be>:

>
> Hi Andrew,
>
> Yes, I think that a combination of BooleanFragments and embedded surfaces
> should do what you want:
>
> SetFactory("OpenCASCADE");
> Block(1) = {-0, 0, 0, 1, 1, 1};
> // intersecting:
> Rectangle(7) = {0.4, 0.7, 0.2, 0.3, 0.3, 0};
> Rectangle(8) = {-0.2, 0.3, 0.5, 0.3, 0.3, 0};
> Rectangle(9) = {0.8, -0.2, 0.5, 0.3, 0.3, 0};
> BooleanFragments{ Volume{1}; Delete; }{ Surface{7:9}; Delete; }
> // fully inside
> Rectangle(30) = {0.3, 0.3, 0.5, 0.3, 0.3, 0};
> Surface {30} In Volume{1};
>
> Christophe
>
>
>
>
> > On 2 May 2017, at 19:57, andrew <armitatz at gmail.com> wrote:
> >
> >
> > hi,
> >
> > In Salome which uses the opencascade model there is a Boolean operation
> called partition. With this you can create a solid from two others but with
> a shared face. A usage of that is the creation of meshes with internal
> walls in it with zero thickness aka 'baffles'. Is there a procedure in gmsh
> that can give the same results given that it has implemented the same
> opencascade model? Obviously there is a way to have such results if you
> give the precise geometry but sometimes it is very difficult to cut
> geometries and it is easier if gmsh could do that.
> >
> > Attached is an image of a mesh with internal baffles created with
> partitioning and the geometry that created it. I would prefer t if gmsh
> could do the meshing but I haven't found a way to load the geometry to gmsh
> from Salome.
> >
> > kind regards
> >
> > Andrew
> >
> > <crop1.jpg><crop2.jpg>_______________________________________________
> > gmsh mailing list
> > gmsh at onelab.info
> > http://onelab.info/mailman/listinfo/gmsh
>
> --
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
>
>
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