Formulation and finite element implementation of a multiplicative model ofcoupled pore-plasticity at finite strains under fully saturated conditions

In this paper we present the formulation and numerical analysis of a finite deformation model of coupled pore-plasticity. Fully saturated conditions a re assumed. The model is based on a multiplicative decomposition of the def ormation gradient in elastic and plastic parts, together with an additive e lastoplastic decomposition of the fluid content. The final relations descri bing the evolution of the different fields are then obtained in the thermod ynamic framework furnished by the principle of maximum plastic dissipation. The particular case of an associated Drucker-Prager model in effective str esses is considered as a model example. A complete characterization of the dissipative structure of the problem of evolution is described through the derivation of an a priori stability estimate. We describe in derail the fin ite element implementation of the model in the context of staggered algorit hms for the solution of the physically coupled problem. Finally, we present representative numerical simulations to illustrate the features of the pro posed models. In particular, the case of strain localization in globally un drained conditions is studied in the proposed framework. (C) 1999 Elsevier Science S.A. All rights reserved.