[Gmsh] Question about tetrahedron element generation with GMSH

[David Colignon]

On 25/08/10 19:12, 류은현 wrote:
> Before asking, Thank you for your kind answer about my preivous question.
>
> It was so helpful to me.
>
> I am working on developing 3D FEM application related with neutronics problem.
>
> Following is my first question
>
> Today I made 3D domain, that has physical volumes. But I saw that the jacobian of certain element is zero.
>
> Because of a element that is consist of 4 nodes which are located on same plane!


Hi,

Did you try the Tools->Options->Mesh->Advanced->"Optimize quality of tetrahedra" option ?

>
> Why does GMSH produce such a strange element? Does it due to my fault in making GMSH input?


Impossible to answer without your .geo file ...

regards,

Dave



--
David Colignon, Ph.D.
Collaborateur Logistique du F.R.S.-FNRS
CÉCI - Consortium des Équipements de Calcul Intensif
ACE - Applied & Computational Electromagnetics
Institut Montefiore B28
Université de Liège
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>
> Of course, I can eliminate that element by giving certain condition to my code, it seems to be strange.
>
> Please tell me in detail, if the reason is related with my input.
>
> My second question is associated with defining volume. I understood that the orientation of surfaces which will
>
> constitute the volume should be consistent. But if we want to make a cube or hexahedron volume, the following order of
>
> surface index is OK? I mean that writing index(upper plane), index(lower plane), index(left plane),.... , not continuously.
>
> Please tell me in detail. Sorry for bothering you.
>
>
>
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