Problem with elements concentration in volume mesh

[IanKarp]

Hello everyone,

I am facing some dificulties with the "Volume Mesh" option in Texgen.

When being meshed, the domain seems to be divided into several subdomains with straigth lines between yarns (picture 1)
I can't explain why, but there is along theses lines a much higher elements density than elsewhere in the volume (picture 2).
I tried to change the "merge tolerance" but it does not seem to have a big influence on this...

Does anyone have an idea how to reduce the elements density in theses zones ?

Thanks in advance for your replies.

Yann

[louisepb]

Hi Yann,
The algorithm which generates the volume mesh first of all finds the outlines of yarns as seen if looking down on the textile and then uses those outlines to triangulate a mesh. The method is describe in this paper: Sherburn, M., A. Long, A. Jones, J. Crookston, and L. Brown, Prediction of textile geometry using an energy minimization approach. Journal of Industrial Textiles, 2012. 41(4): p. 345-369.

The merge tolerance gives the size of gap between yarns which will be taken as two yarns next to each other, rather than having an element of matrix between them.

The algorithm was originally developed to work well with single layer 2D textiles and the artifacts that you are seeing show up limitations of the algorithm for layered textiles. There hasn't, as yet, been any attempt to improve the algorithm for the more complex textiles which TexGen is now able to generate. You might be better trying a different meshing method.

Hope that helps,
Louise

[IanKarp]

Hi Louise,

Thanks for your reply.

Indeed, I wanted to use another software but had several problems with exporting a smooth geometry so I decided to mesh in Texgen.

Finally, I have partially solved my problem by using a periodic mesh. I can't explain why, but with this option, there is much less zones with high element density.

Hope that will help someone.

Yann

[louisepb]

Hi Yann,

That's interesting. It must be something to do with the extra constraints which are applied in order to create the periodicity. Glad it's working for you.

I am aware of the issues with the export and am intending to investigate changing to a newer version of OpenCascade at some point but there have been some fairly major changes so it will need some significant changes to the TexGen interface to get it working. I'm not sure about the timescale on that one!

Best regards,
Louise

[Amateur]

Hey Yann,

Please tell me how you have visualized the mesh? I'm desperately looking for a possibility to display the mesh created by TexGen, respectively Triangle.

Or can anyone else help me?

Thank you for your reply in advance!

Lena.

[louisepb]

Hi Lena,

If you save the mesh as a .vtu then you can visualise it using Paraview. If you save as a .inp file then you can view in ABAQUS.

Best wishes,
Louise