Effect of mesh size on simsolid result in conversion of implicit lattice geometry to triangle mesh

EnesKurt
EnesKurt Altair Community Member
edited March 31 in Community Q&A

Hi there,

I wanted to do a simple static analysis using lattice structures produced as implicit geometry in the Altair Inspire program. After adding lattice to the inside of my model, I converted the geometry with the "Convert to triangle mesh" tool and performed the analysis with the Simsolid solver.

My problem in this part is that the analysis result changes a lot in different triangle mesh sizes and even if I did a few analyzes, I could not achieve convergence in the result. The contour appearances of the analysis results are similar, but there are big differences in the stress and displacement results. How can I get the correct result?

Additionally, I applied the mesh convergence method. I applied a much smaller mesh to the geometry, but even though the mesh size was very small, there was no convergence in the results. Errors such as 5%-10% in the results may be acceptable, but instead there were differences too high.


In the geometry I used, there are 2 flat plates of 24mmx24mmx5mm at the top and bottom and a 24mmx24mmx48mm lattice section in the middle. After the convert process, I combined the top and bottom plates and the lattice section with "Boolean".

F: 500 N (on the top plate)
Support: Fixed (on the bottom plate)
Material: PLA (E: 2865 MPa, Nu: 0.35, Density: 0.00124 g/mm3, Yield Stress: 56 MPa)
Lattice features:
Type: Hex Truss
Strurt Diameter: 1mm,
Cell Size: 2x2x4,
Visualization Quality: Very High

altair.png

Another result with more triangle mesh size and better run options:

meshsizeconverg.png

Answers

  • Carlton Matthew_20281
    Carlton Matthew_20281 Altair Community Member

    This is perhaps not the best geometry for convergence, since it has many sharp corners which generate singularities. The addition of fillets could improve the convergence results.