[Gmsh] Hex-Mesh problem

[Christophe Geuzaine]

Hi Martin,

General (high-quality) full-hex meshes are not available: it's a current research topic. For high-quality full-hex meshes without extrusion, your best bet is to generate a fully structured grid - see attached file. Otherwise you'll have to either accept a hex-dominant mesh (we are actively working on this) ; or a low-quality hex mesh (using the subdivision algorithms).

Christophe



> On 22 Mar 2018, at 18:24, Martin.Raedel at dlr.de wrote:
> 
> Hello,
>  
> are there any new possibilities for this problem using the new OpenCascade-options? Or is there any option to specify the layers of an extrusion by surface meshes?
>  
> Regards
> Martin
>  
> Von: gmsh [mailto:gmsh-bounces at ace20.montefiore.ulg.ac.be] Im Auftrag von Martin.Raedel at dlr.de
> Gesendet: Mittwoch, 16. November 2016 16:30
> An: gmsh at onelab.info
> Betreff: Re: [Gmsh] Hex-Mesh problem
>  
> Hello again,
>  
> I got the desired result using an Extrusion:
>  
> <image001.png>
>  
> However, using Extrusion greatly disagrees with my modelling approach, since I create all required geometry (points, lines, surfaces, volumes) already in advance, before calling gmsh. Afterwards, I want to mesh the model with gmsh and  in a third step assign the created mesh to the existing geometry. Is there any way to create a (semi-)structured mesh using volumes already defined in my geo-file?
>  
> Best regards
> Martin
>  
> Von: gmsh [mailto:gmsh-bounces at ace20.montefiore.ulg.ac.be <mailto:gmsh-bounces at ace20.montefiore.ulg.ac.be>] Im Auftrag von Martin.Raedel at dlr.de <mailto:Martin.Raedel at dlr.de>
> Gesendet: Dienstag, 15. November 2016 17:23
> An: gmsh at onelab.info <mailto:gmsh at onelab.info>
> Betreff: [Gmsh] Hex-Mesh problem
>  
> Hello,
>  
> I experience difficulties creating a pure or at least Hex-dominant mesh for the model in the text file. I tried a lot of solver options but even with the frontal algorithm and AllHexas subdivision algorithm I cannot get a proper mesh. Volume elements are only created for the left and right volume while the boundary surfaces of the middle volume are meshed but no volumes are created and different errors are thrown by gmsh, e.g.
>  
> “Cannot use frontal 3D algorithm with quadrangles on boundary” for frontal 3D
>  
> Is there any way that I am missing? Do I somehow have to mesh the middle volume first?
>  
> Best regards
> Martin Rädel
>  
> ————————————————————————
> Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
> German Aerospace Center
> Institute of Composite Structures and Adaptive Systems | Structural Mechanics | Lilienthalplatz 7 | 38108 Braunschweig | Germany
>  
> Dipl.-Ing. Martin Rädel
> Telephone +49 (0)531 295-2048 | Telefax +49 (0)531 295-2232 | martin.raedel at dlr.de <mailto:martin.raedel at dlr.de>
> www.DLR.de <http://www.dlr.de/>
>  
> _______________________________________________
> gmsh mailing list
> gmsh at onelab.info
> http://onelab.info/mailman/listinfo/gmsh

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://onelab.info/pipermail/gmsh/attachments/20180325/2ca5dbce/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: geometry_minimal_3D_structured.geo
Type: application/octet-stream
Size: 4000 bytes
Desc: not available
URL: <http://onelab.info/pipermail/gmsh/attachments/20180325/2ca5dbce/attachment-0001.geo>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://onelab.info/pipermail/gmsh/attachments/20180325/2ca5dbce/attachment-0003.html>