The refined hybrid isoparametric element method for solid structures

Based on a new variational principle with independent variables of displacements, strains and stresses and with weaker constraint conditions of interelement continuity, the refined hybrid isoparametric element method is developed by using an orthogonal approach. In this method the element stiffness matrix can be decomposed into a series of stiffness matrices with respect to assumed strain modes and can be derived explicitIy or by using lower order numerical integration. Numerical examples are given to demonstrate the effectiveness of the proposed elements in terms of convergence and accuracy and also in its being less sensitive to distorted mesh.