In this article, a novel dual-primal mixed formulation for second-order elliptic problems is proposed and analyzed. The Poisson model problem is considered for simplicity. The method is a Petrov-Galerkin mixed formulation, which arises from the one-element formulation of the problem and uses trial f
A nonconforming mixed finite element for second-order elliptic problems
โ Scribed by Mohamed Farhloul; And Michel Fortin
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 131 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0749-159X
No coin nor oath required. For personal study only.
โฆ Synopsis
In a recent work, Hiptmair [Mathematisches Institut, M9404, 1994] has constructed and analyzed a family of nonconforming mixed finite elements for second-order elliptic problems. However, his analysis does not work on the lowest order elements. In this article, we show that it is possible to construct a nonconforming mixed finite element for the lowest order case. We prove the convergence and give estimates of optimal order for this finite element. Our proof is based on the use of the properties of the so-called nonconforming bubble function to control the consistency terms introduced by the nonconforming approximation. We further establish an equivalence between this mixed finite element and the nonconforming piecewise quadratic finite element of Fortin and Soulie [
๐ SIMILAR VOLUMES
A least-squares mixed ยฎnite element method for the second-order non-self-adjoint two-point boundary value problems is formulated and analysed. Superconvergence estimates are developed in the maximum norm at Gaussian points and at Lobatto points.
Our work is an extension of the previously proposed multivariant element. We assign this reยฎned element as a compact mixed-order element in the sense that use of this element offers a much smaller bandwidth. The analysis is implemented on quadratic hexahedral elements with a view to analysing a thre
Numerical modelling of exterior acoustics problems involving in"nite medium requires truncation of the medium at a "nite distance from the obstacle or the structure and use of non-re#ecting boundary condition at this truncation surface to simulate the asymptotic behaviour of radiated waves at far "e
In a previous paper a modified Hu-Washizu variational formulation has been used to derive an accurate four node plane strain/stress finite element denoted QE2. For the mixed element QE2 two enhanced strain terms are used and the assumed stresses satisfy the equilibrium equations a priori for the lin