A Finite Element Formulation for Nonlinear Incompressible Elastic and Inelastic Analysis

Ahatract-We introduce a displacement-pressure (u/p) finite element formulation for the geometrically and materially nonlinear analysis of compressible and almost incompressible solids. The u/p formulation features the a priori replacement of the pressure computed from the displacement field by a separately interpolated pressure; this replacement is petformed without reference to any specific material description. Comiderations for incremental nonlinear analysis (including contact boundary conditions) are discussed and various u/p elements are studied. Numerical examples show the performance of the u/p formulation for twoand three-dimensional problems involving isotropic, orthotropic, rubber-like and clasto-plastic materials.