Poroelastic two-phase material modeling: theoretical formulation and embedded finite element method implementation

Abstract

This paper presents the formulation of FEMs for the numerical modeling of a poroelastic two-phase (aggregates/mixture phase) solid. The displacement and pressure fields are decomposed, following the Enhanced Assumed Strain (EAS) method, into a regular part and an enhanced part. This leads to discontinuous strain and pressure gradient fields allowing to capture the jump in mechanical and hydrical properties passing through the interface between the aggregates and the mixture phase. All these enhanced fields are treated in the context of the embedded FEM through a local enhancement of the finite element interpolations as these jumps appear. The local character of these interpolations leads after a static condensation of the enhanced fields to a problem exhibiting the same structure as common poroelastic finite element models but incorporating now the mechanical and hydrical properties of a two-phase solid. Copyright © 2015 John Wiley & Sons, Ltd.