Nonconforming elements in the mixed finite element method. (English) Zbl 0573.65083

An error estimate for the mixed finite element of the approximation of a class of elliptic problems is derived in the general setting using the nonconforming elements. The error estimate obtained in this paper generalizes the previous known results. In addition to this, a class of nonconforming rectangular elements is proposed and analysed and applied to Stokes equations. In this case, the derived error estimates are optimal.
Reviewer: M.A.Noor


65N30 Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs
65N15 Error bounds for boundary value problems involving PDEs
35J25 Boundary value problems for second-order elliptic equations