[Gmsh] surface mesh, connect the faces of a compound

[Bernd Hahnebach]

Hi Dave,

thanks for the tipp regarding the gui and using the options over  
there. I had not worked with the gui before. I did some teste with  
some modells and the different options. I need to work more to get  
used to the gui of GMSH. Up to date it worked out well for some models.

I have a further question in this regard. What would be needed for  
beam or solid meshes ?


beam meshes (or edge meshes) --> connect the edges where they share  
the same vertice --> ?

shell mehes --> connect the faces where they share the same edge -->   
-string "Geometry.OCCSewFaces=1;"

solid meshes (or volume meshes) --> connect the solids where they  
share the same face --> ?


I could provide steps if needed.


Kind regards Bernd




Zitat von David Colignon <david.colignon at ulg.ac.be>:

>
> On 22/09/15 08:03, Bernd Hahnebach wrote:
>
>> Hi David,
>>
>> thanks for the fast reply. It is what I would like to have connect  
>> the faces if they share an edge. Yes the provided option
>> seams to do the trick.
>>
>> -string "Geometry.OCCSewFaces=1;"
>>
>> It worked on the simple provided part compound_of_faces.step and on  
>> one with 10 faces beam-10faces.step. With bothe the FEA
>> worked out very well :-) On a more sophisticated part  
>> mechanical-part.step it seam to work out too but I get non positive
>> jacobian during FEA, but that seams to be another part of the story.
>
>
> Hi,
>
> for more complicated parts, you should also open your step file  
> directly with Gmsh, and try the other options "Remove degenerated  
> edges and faces", "Remove small edges", ... in Tools -> Options ->  
> Geometry -> General and also look at the Info messages.
>
> Regards,
>
> Dave
>
>>
>> Downloadlink is still:
>> https://cloud.woelkli.com/public.php?service=files&t=1cfd13febed7694726b902cdb36476d4
>>
>> I need to test on more examples. I will report back.
>>
>> kind regards bernd
>>
>>
>>
>>
>> Zitat von David Colignon <david.colignon at ulg.ac.be>:
>>
>>>
>>> Hi Bernd,
>>>
>>> can you try with adding    the
>>>
>>> -string "Geometry.OCCSewFaces=1;"
>>>
>>> option ?
>>>
>>> This should work with relatively simple geometries, i.e. faces  
>>> sharing a common line.
>>>
>>> Regards,
>>>
>>> Dave
>>>
>>> --
>>> David Colignon, Ph.D.
>>> 1er logisticien de recherche
>>> Université de Liège
>>> ACE - Applied & Computational Electromagnetics
>>> Sart-Tilman B28
>>> 10, Grande Traverse
>>> 4000 Liège - BELGIQUE
>>> Tél: +32 (0)4 366 37 32
>>> http://www.ulg.ac.be/nic4
>>>
>>> On 21/09/15 19:25, Bernd Hahnebach wrote:
>>>> Hi there,
>>>>
>>>> This is my first post to the mailing list so I may introduce  
>>>> myself first. The "identifier" given to
>>>> me by my parents is Bernd and this corresponds to what most  
>>>> people call myself. The bred to feed
>>>> myself an my familiy I earn in an engineering office near Zuerich  
>>>> in Switzerland. I'm structural
>>>> engineer in the building industry. In my spare time I develop on  
>>>> the FEM Workbench and on the Arch
>>>> Workbench of the parametric open source cad plattform FreeCAD.  
>>>> This is why I'm gone write to this list.
>>>>
>>>>
>>>> FreeCAD uses for internal parametric surface and solid meshing  
>>>> netgen. AFAIK due to licence
>>>> incompatibility between FreeCAD and GMSH it has never been an  
>>>> option to use GMSH instead. But there
>>>> exists a FreeCAD macro which uses the GMSH installed on ones  
>>>> computer for meshing. Most users mainly
>>>> use this GMSH macro for meshing their models including myself.  
>>>> The macro exports a *.step meshes
>>>> with GMSH and imports the *.unv mesh back into FreeCAD. Babbled  
>>>> enought,the important part of the
>>>> post ...
>>>>
>>>>
>>>> I run into trouble with meshing compunds of faces. The faces  
>>>> where not connected to each other and
>>>> thus a Finite Element Analysis will fail to work without manual  
>>>> connection off all the faces of the
>>>> compund. As a example a very simple compund of just two faces is taken.
>>>>
>>>> mesh command:
>>>> gmsh compound_of_faces.step -3 -format unv -o  
>>>> compound_of_faces.unv -algo netgen -clmax 100,00
>>>> -order 2 -optimize
>>>>
>>>> gmsh --version
>>>> 2.8.5
>>>> on Debian Jesie
>>>>
>>>> I was wondering if it is possible to tell GMSH to mesh a  
>>>> connected Surface Mesh of a compund of faces?
>>>>
>>>> The files could be downloaded here:
>>>> https://cloud.woelkli.com/public.php?service=files&t=1cfd13febed7694726b902cdb36476d4
>>>>
>>>>
>>>> Kind Regards and thanks to all people who have ever contributed  
>>>> to GMSH development.
>>>>
>>>> Bernd
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> gmsh mailing list
>>>> gmsh at geuz.org
>>>> http://www.geuz.org/mailman/listinfo/gmsh
>>>
>>
>>
>>
>
>
>