# [Gmsh] Composite RVE

Hossam Ragheb har1g15 at soton.ac.uk
Fri Dec 18 16:33:39 CET 2020

```Apologies for the late reply. Thanks Christophe, It works fine now.

Regards, Hossam

On 14/12/2020 20:50, Christophe Geuzaine wrote:
> CAUTION: This e-mail originated outside the University of Southampton.
>
>> On 10 Dec 2020, at 14:34, Hossam Ragheb <har1g15 at soton.ac.uk> wrote:
>>
>> Hi,
>>
>> I am new to gmsh, so apologies if the answer to my question is obvious.
>>
>> I coded a .geo file (Attached) to create 3D RVE with fibers in a matrix that includes voids.
>>
>> The process simply is :
>>
>>      1- Create box of the matrix material.
>>
>>      2- Create voids using Sphere command and BooleanDifference to remove these from the matrix material.
>>
>>      3- Create fibers as Cylinders and and utilise BooleanFragments to include the cylinders in the matrix.
>>
>> I have one persistent problem, once the mesh is created the fibers are meshed as hollow cylinders, however i need them to be solid.
>>
>> Its interesting behavior. Last thing to note that mesh size affects the outcome, for example when the min/max mesh size is 2, the result is solid cylinders, but with mesh size of 1, it becomes hollow.
>>
>> It there a way to force the meshing algorithm to mesh the cylinder as solid object?
>>
>> I have attached the .geo file, please let me know if you can help.
>>
>> Any suggestions?
>
> The geometry is a bit tricky: it's almost degenerate (with some cylinders very close to the boundary), and the parametrization of some curves does not seem monotonic. I've successfully meshed with the following parameters:
>
> MeshSize{305, 310} = 0.5;
> Mesh.MeshSizeMax = 2; // successfully tested with 1 and 2
> Mesh.AngleToleranceFacetOverlap = 1e-6;
> Mesh.Algorithm3D = 10;
>
> Christophe
>
>
>> Thanks,
>>
>> Hossam Ragheb
>>
>> <RVE_rev1.geo>_______________________________________________
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> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science