search

mimesis-inria / caribou

Multi-physics computation library
GNU Lesser General Public License v3.0
29 stars 17 forks source link

Difference for hexahedron quadratic between Caribou and FEniCS #119

Closed Ziemnono closed 1 year ago

Ziemnono commented 2 years ago

We observed a remarkable difference in stiffness matrix between Caribou and FEniCS. @Ziemnono provides Gauss points for FEniCS.

Ziemnono commented 1 year ago

This difference is normal given the fact that the elements use different interpolation schemes. In FEniCS, the Serendipity element (20 dofs https://defelement.com/elements/serendipity.html) are using integral over edges for second quadratic elements, while that is on a vertex in Caribou. But the solution is the same for the displacement , just the R and K matrices are not the same.