AN ENHANCED HYBRID POST-PROCESSING PROCEDURE FOR IMPROVING STRESS SOLUTIONS OF DISPLACEMENT-BASED PLATE BENDING ELEMENTS

In this paper, a new simple enhanced hybrid post-processing procedure is presented in order to improving internal force or stress solutions of displacement-based plate bending elements. Firstly, the displacement solutions are obtained by the standard method for the displacement-based elements. Secondly, the internal force fields, which satisfying the equilibrium equation of plates, are assumed by introducing several unknown parameters. Then by utilizing the Hellinger-Reissner variational principle, the relationships between those parameters and the displacement solutions are established. Thus, the internal force or stress solutions are determined by the new relationships instead of the traditional stress-strain relationships. Numerical examples show that by using the proposed method, the accuracy of the internal force or stress solutions of the displacement-based plate bending elements is improved significantly. The enhance hybrid elements possess the advantages of both displacement elements and hybrid elements, being characterized by relatively simple formulation, high accuracy for both displacements and stresses.