[Gmsh] Difficulty with generating a volume mesh from a stl file

[David Love]

Dear Sir/Madam,

I have been experiencing difficulties generating a volume mesh (.geo and
.msh) from a surface mesh (.stl) generated in matlab. The main issue is
that I end up with zero volume tetrahedra (elements with four collinear
points) which causes difficulties in subsequent finite element simulations.

I have attached an example of a surface mesh (.stl) that I start off with.
I then use the procedure outlined in the following link to create the
volume mesh (.geo and .msh):
http://fengl.org/2012/05/21/converting-stl-surface-mesh-to-volume-mesh-using-gmsh/

*My questions are:*
- Is there a way to avoid zero volume tetrahedra or does the issue
originate from the matlab generated stl file? Do you have a suggestion to
avoid this issue?
- Is there a possibility of generating a volume mesh in GMSH by defining
the surface boundary in an equation? For instance if I describe my shape in
form of a triple sinusoidal (as done in the matlab code) and then tell GMSH
to mesh the inner volume. If so could you point me towards some examples?

Thank you very much for your time.
I would appreciate any suggestions that you may have.

Kind regards,
David


-- 
David Love

PhD Candidate in Physics
Cavendish Laboratory
University of Cambridge

Office: +44 (0)1223 764169
Email: dml42 at cam.ac.uk
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