Stress function approach

TL;DR: In this article, a mixed finite element procedure for plane elasticity is introduced and analyzed, and the symmetry of the stress tensor is enforced through the introduction of a Lagrange multiplier.

TL;DR: In this paper, deux families d'elements finis mixtes for des problemes aux limites elliptiques d'ordre 2 en dimension 2 and 3 were introduced.

TL;DR: In this article, a new mixed finite element formulation for the equations of linear elasticity is considered, where the variables approximated are the displacement, the unsymmetric stress tensor and the rotation.

TL;DR: New finite element methods for the approximation of the equations of linear elasticity in three space dimensions that produce direct approxima- tions to both stresses and displacements are constructed.

TL;DR: In this article, the main details of a triangular element which satisfies equilibrium conditions between the adjacent elements and which is used in conjunction with the complementary energy principle are provided, where the bending moments vary linearly within the element and use is made in the derivation of the analogy that exists between problems of plane stress and plate bending.

TL;DR: In this paper, the basic flexibility matrix of an isoparametric stress element is defined, and the rank technique is adopted to automatically extract the zero stress modes such that the element can be completely interchangeable between any finite element system.