Abstract
This paper constructs the first mixed finite element for the linear elasticity problem in 3D using P3 polynomials for the stress and discontinuous P2 polynomials for the displace-ment on tetrahedral meshes under some mild mesh conditions. The degrees of freedom of the stress space as well as the corresponding nodal basis are established by characterizing a space of certain piecewise constant symmetric matrices on a patch around each edge. Macro-element techniques are used to define a stable interpolation to prove the discrete inf-sup condition. Optimal convergence is obtained theoretically.
| Original language | English |
|---|---|
| Pages (from-to) | 1444-1468 |
| Number of pages | 25 |
| Journal | Journal of Computational Mathematics |
| Volume | 43 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 31 Oct 2025 |
Keywords
- Discrete inf-sup condition
- Linear elasticity
- Lower order mixed elements
- Macro-element techniques