Add 3D circular beam MMS validation: SOFA vs FreeFEM vs Saint-Venant analytical - #40
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Pushed a small modification for passing parameters.
Let's close these and unify them later.
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#Summary
Adds a new cross-validation case for a 3D beam with circular cross-section under axial traction, extending the tetrahedral MMS validation pipeline (previously only rectangular cross-sections). Compares SOFA, FreeFEM++, and the exact Saint-Venant analytical solution.
beam3d_circular_tet.py : Gmsh mesh generator
freefem_beam3d_circle_traction.edp : FreeFEM++ weak formulation
sofa_beam3d_circle_traction.py : SOFA scene (LinearSmallStrainFEMForceField, consistent nodal traction forces on the loaded face)
comparaison_script3d_circle.py : coordinate-matching comparison script (SOFA vs FF vs analytical)
params.json / params_beam3d_circle_traction.json: mesh and physical parameters
Results
SOFA vs FreeFEM: RMS ≈ 1e-12 (ux), 6e-14 (uy), 4e-14 (uz) : effectively machine precision
SOFA/FreeFEM vs analytical (x ≥ 0.2, i.e. away from the clamped end): RMS ≈ 2.3e-3 (ux), 7.1e-4 (uy), 1.8e-3 (uz); consistent with expected mesh discretization error