Article
Keywords:
elliptic model problem; dual variational formulation; piecewise linear finite elements; a priori error estimates; a posteriori error estimates; two-sided bounds
Summary:
For an elliptic model problem with non-homogeneous unilateral boundary conditions, two dual variational formulations are presented and justified on the basis of a saddle point theorem. Using piecewise linear finite element models on the triangulation of the given domain, dual numerical procedures are proposed. By means of one-sided approximations, some a priori error estimates are proved, assuming that the solution is sufficiently smooth. A posteriori error estimates and two-sided bounds for the energy are also deduced.
References:
[1] J. Nečas:
Les méthodes directes en théorie des équations elliptiques. Academia, Prague 1967.
MR 0227584
[2] G. N. Jakovlev:
Boundary properties of functions of class $W_p^{(1)}$ on the domains with angular points. (in Russian). DAN SSSR, 140 (1961), 73-76.
MR 0136988
[3] I. Hlaváček:
Dual finite element analysis for unilateral boundary value problems. Aplikace matematiky 22 (1977), 14-51.
MR 0426453
[4] J. Céa:
Optimisation, théorie et algorithmes. Dunod, Paris 1971.
MR 0298892
[6] I. Hlaváček:
Some equilibrium and mixed models in the finite element method. Proceedings of the Banach Internat. Math. Center, Warsaw (to appear).
MR 0514379