Reference problem ===================== Geometry --------- It is an elliptical crack immersed in a medium that is supposed to be infinite. We only model one eighth of a parallelepiped: Material properties -------------------- :math:`E=210\mathrm{000.MPa}` :math:`\nu \mathrm{=}0.3` Boundary conditions and loads ------------------------------------- Symmetry with respect to the 3 main planes: :math:`{U}_{x}=0.` in the :math:`X=0` plan. :math:`{U}_{Y}=0.` in the :math:`Y=0` plan. :math:`{U}_{Z}=0.` in the :math:`Z=0.` plane out of the crack The loading conditions are either: :math:`P=1\mathrm{MPa}` in plane :math:`Z=1250\mathrm{mm}` (modeling :math:`A`) either: :math:`\mathrm{FZ}={8.10}^{-4}N/{\mathrm{mm}}^{3}` on all volume elements (loading equivalent to the previous one) (models :math:`F` and :math:`G`).