Quasi-conforming element and the new formulation of hybrid/mixed element

By the means of displacements separating and additional internal displacements being expressed bubble functions in the derivation of quasi-conforming element formulation, the element stiffness matrix constructed in this paper is equal to the new formulation of hybrid/mixed element by the Hu-Washizu generalized variational principle relaxing continuous conditions. This indicates the general relation of quasi-conforming element and generalized variational principle.