TANGENTIAL-DISPLACEMENT AND NORMAL-NORMAL-STRESS CONTINUOUS MIXED FINITE ELEMENTS FOR ELASTICITY.

In this paper, we introduce new finite elements to approximate the Hellinger Reissner formulation of elasticity. The elements are the vector-valued tangential continuous Nédélec elements for the displacements, and symmetric tensor-valued, normal-normal continuous elements for the stresses. These elements do neither suffer from volume locking as the Poisson ratio approaches ½, nor suffer from shear locking when anisotropic elements are used for thin structures. We present the analysis of the new elements, discuss their implementation, and give numerical results. [ABSTRACT FROM AUTHOR]