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...? Anyway, my problem is solved. :) Matthias > -----Ursprüngliche Nachricht----- > Von: Christophe Geuzaine [mailto:[email protected]] > Gesendet: Freitag, 10. Mai 2019 15:54 > An: Zenker, Dr. Matthias > Cc: [email protected] > 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@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 > > > > _______________________________________________ > > gmsh mailing list > > [email protected] > > https://urldefense.proofpoint.com/v2/url?u=http-3A__onelab.info_mailma > > n_listinfo_gmsh&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-IVyyYW- > Ff2gY > > > &r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57DMr4&m=V_7B61tkQ0a > Yr8Dezsuzw > > > aT6IOdg8G3w2HF5YVGbVTg&s=LaR6M5F9m0GO2ghW8OhahHTqcLsq6D7xJpCII > NHKZJc&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=V_7B61t > kQ0aYr8DezsuzwaT6IOdg8G3w2HF5YVGbVTg&s=PkAHPwRcNSOfLCHPv70Fl2R7 > aGOAgiL2R0DWN3QE_dM&e= > > ________________________________ Erbe Elektromedizin GmbH Firmensitz: 72072 Tuebingen Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht: Stuttgart HRB 380137 _______________________________________________ gmsh mailing list [email protected] http://onelab.info/mailman/listinfo/gmsh
