[Gmsh] Additional surface after boolean operation on volume boundary

[Zenker, Dr. Matthias]

Thank you!

> -----Ursprüngliche Nachricht-----
> Von: Christophe Geuzaine [mailto:cgeuzaine at uliege.be]
> Gesendet: Montag, 13. Mai 2019 23:31
> An: Zenker, Dr. Matthias
> Cc: gmsh at onelab.info
> Betreff: Re: [Gmsh] Additional surface after boolean operation on volume
> boundary
>
>
>
> > On 13 May 2019, at 11:18, Zenker, Dr. Matthias <Matthias.Zenker at erbe-
> med.com> wrote:
> >
> > Hi Christophe,
> >
> > thank you, that works!
> >
> > Remark:
> > BooleanFragments seems to renumber all surfaces of the cube. So for the
> physical surface definitions, we have to guess in advance which numbers the
> surfaces will get, or use the GUI...?
>
> You can use the "Boundary" operator ; or search for the surfaces geometrically
> with "In BoundingBox".
>
> Christophe
>
> > Anyway, my problem is solved. :)
> >
> > Matthias
> >
> >> -----Ursprüngliche Nachricht-----
> >> Von: Christophe Geuzaine [mailto:cgeuzaine at uliege.be]
> >> Gesendet: Freitag, 10. Mai 2019 15:54
> >> An: Zenker, Dr. Matthias
> >> Cc: gmsh at onelab.info
> >> Betreff: Re: [Gmsh] Additional surface after boolean operation on
> >> volume boundary
> >>
> >>
> >> Use Fragments:
> >>
> >> SetFactory("OpenCASCADE");
> >> Box(1) = {-25, -25, -50, 50, 50, 50};
> >> Disk(7) = {0, 0, 0, 0.5, 0.5};
> >> BooleanFragments{ Surface{7}; Delete; }{ Volume{1}; Delete; }
> >> Characteristic Length {9} = 0.05; Physical Volume("bulk") = {1};
> >> Physical Surface("disk") = {7};
> >>
> >> Christophe
> >>
> >>
> >>> On 10 May 2019, at 13:06, Zenker, Dr. Matthias
> >>> <Matthias.Zenker at erbe-
> >> med.com> wrote:
> >>>
> >>> Hi,
> >>>
> >>> I try to create a block with the top surface containing a disk:
> >>>
> >>> //+
> >>> SetFactory("OpenCASCADE");
> >>> //+
> >>> Box(1) = {-25, -25, -50, 50, 50, 50}; //+
> >>> Disk(7) = {0, 0, 0, 0.5, 0.5};
> >>> //+
> >>> BooleanDifference{ Surface{6}; Delete; }{ Surface{7}; } //+
> >>> Characteristic Length {9} = 0.05; //+ Delete {  Volume{1}; } //+
> >>> Surface Loop(2) = {1, 3, 5, 4, 2, 6, 7}; //+
> >>> Volume(1) = {2};
> >>> //+
> >>> Physical Volume("bulk") = {1};
> >>> //+
> >>> Physical Surface("disk") = {7};
> >>> //+
> >>> Physical Surface("top") = {6};
> >>> //+
> >>> Physical Surface("bottom") = {5};
> >>> //+
> >>> Physical Surface("side") = {1, 4, 2, 3};
> >>>
> >>> The problem is that the surface 6 is not attached to the volume, but
> >>> there is a
> >> new surface 8 instead which is identical to surface 6, and which is
> >> used for the volume.
> >>> Consequently, when I create a mesh, the boundary corresponding to
> >>> surface 6
> >> is not attached to the volume, i.e. the nodes of surface 6 do not
> >> figure in tetrahedra of the volume, and surface 6 is not recognized by Elmer
> on import.
> >>> What do I do wrong?
> >>>
> >>> Thank you for a hint,
> >>> Matthias
> >>>
> >>>
> >>>
> >>> Erbe Elektromedizin GmbH Firmensitz: 72072 Tuebingen
> >>> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht:
> >>> Stuttgart HRB 380137
> >>>
> >>> _______________________________________________
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> IVyyYW-
> >> Ff2gY
> >>>
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> >>>
> >>
> aT6IOdg8G3w2HF5YVGbVTg&s=LaR6M5F9m0GO2ghW8OhahHTqcLsq6D7xJpCII
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> >>
> >> —
> >> Prof. Christophe Geuzaine
> >> University of Liege, Electrical Engineering and Computer Science
> >> https://urldefense.proofpoint.com/v2/url?u=http-
> >> 3A__www.montefiore.ulg.ac.be_-
> >> 7Egeuzaine&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-IVyyYW-
> >>
> Ff2gY&r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57DMr4&m=V_7B61t
> >>
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> >> aGOAgiL2R0DWN3QE_dM&e=
> >>
> >>
> >
> > ________________________________
> >
> > Erbe Elektromedizin GmbH Firmensitz: 72072 Tuebingen
> > Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht:
> > Stuttgart HRB 380137
> >
> > _______________________________________________
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> K_3QPZxjUp8ZuOhyGw20jw&s=Ol1YvoxbGgdp4ITtKVNFR18B3xXsX0HoGOQtW
> QaX1Ew&e
> > =
>
> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> https://urldefense.proofpoint.com/v2/url?u=http-
> 3A__www.montefiore.ulg.ac.be_-
> 7Egeuzaine&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-IVyyYW-
> Ff2gY&r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57DMr4&m=uGUb5g
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> iZ5M&e=
>
>

________________________________

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