On mixed variational formulations of linear elasticity using nonsymmetric stresses and displacements

Enforcement of the symmetry constraint on the stress tensor in dual mixed variational principles using nonsymmetric stresses is usually achieved through introducing the rotations as Lagrange multipliers. This paper presents a new way for imposition of the symmetry requirement on the stress tensor assumed to he not a priori symmetric. The central idea in our approach is to find symmetry-equivalent conditions that can be incorporated into the corresponding variational principles using the displacements as Lagrange multipliers. 0 1997 Elsevier Science Ltd. All rights reserved.