Stabilized finite elements applied to elastoplasticity: Ⅰ. Mixed displacement-pressure formulation

摘要

A stabilized, mixed, displacement-pressure (u-p), finite element formulation for elasto-plastic solid media is developed in this paper. In particular it applies to low order finite elements with equal interpolation order for both displacement and pressure fields. The approach successfully eliminates the effect of volumetric locking for elastic nearly incompressible media and the elasto-plastic media exhibiting incompressible or dilatant plastic flow. The performance of the proposed formulation is compared with the stabilized formulation based on pressure Laplacian. It is shown that the proposed stabilized formulation also supports mixing different elements.