Non-linear analysis of structures using high performance hybrid elements

In this work, we describe the formulation and implementation for stress-based hybrid elements for conducting non-linear analysis of elastic structures. The motivation behind developing these elements is that they should be as simple to use as standard displacement-based isoparametric brick elements, but at the same time, be relatively immune to the shortcoming that these elements suffer from, namely, ‘locking’ problems which occur when they are used to model plate/shell geometries, almost incompressible materials or when the elements are distorted, and so on. The formulation is based on a two-field mixed variational principle. Numerical examples are presented to demonstrate the excellent performance of the proposed elements on a variety of challenging problems involving very large deformations, buckling, mesh distortions, almost incompressible materials, etc. Copyright 2006 John Wiley & Sons, Ltd