On finite strain poroplasticity with reversible and irreversible porosity laws. Formulation and computational aspects

The main purpose of this paper is the formulation of a poroplastic framework suitable for finite strain and high pore pressure in saturated porous media. Here we make a distinction between poroplasticity with totally reversible porosity and poroplasticity with the occurrence of irreversible porosity. For this latter, an important key point is that the total porosity is not additively decomposed as usual into reversible and irreversible parts. As shown, the permanent porosity is embedded into the definition of the total porosity itself. The approach is built around the physical restriction that the actual Eulerian porosity is bounded in the interval [0,1] for any admissible process. Elementary considerations motivate the modeling throughout the paper and the formulation is integrated within the unified continuum thermodynamics of open media, which is crucial in setting the convenient forms of the state laws and evolution equations for the flux variables to fully characterize the behavior of porous materials. On the numerical side, the algorithmic design is described in detail for an easy implementation within the context of the finite element method. Finally, we present a set of numerical simulations to illustrate the effectiveneis of the proposed framework. (C) 2013 Elsevier Ltd. All rights reserved.