Improvement of stress accuracy in the hybrid finite element method

Abstract

We describe how to improve the accuracy of stress in the application of the hybrid finite element method. The idea is based on the fact that the assumed stress hybrid method is equivalent to both the principle of minimum complementary energy within the interior of each element and the principle of the minimum potential energy in the entire domain. It is known that when a good hybrid model is used for the displacement solution, the stress model must satisfy equilibrium within individual elements and be comparable with the boundary displacements. However, the compatibility in the elements is usually ignored and through variational operation it may be only approximately satisfied. So the stress model cannot approach a corresponding analytical stress field. In the present study, after nodal displacements are solved, we propose that a different stress model could be used to find the stress coefficients according to the principle of minimum complementary energy in each element in order to get an improved stress field.

Citation

Cheng Huang, H. and Yu Zhang, J. (1986), "Improvement of stress accuracy in the hybrid finite element method", Engineering Computations, Vol. 3 No. 1, pp. 73-76. https://doi.org/10.1108/eb023643