Mixed Finite Element Methods with Continuous Stresses

摘要

We present a modified mixed formulation for second order elliptic equations andlinear elasticity problems which automatically satisfies the ellipticity on the kernel condition, i.e., one of the two compatibility conditions necessary to ensure stability and optimal error bounds (the other being the Inf-Sup condition). This modification differs from similar ones introduced by other authors in that it is independent of the mesh size. Moreover, it allows the use of continuous stresses.