A 3-D hierarchical Fe formulation of Biot's equations for elasto-acoustic modelling of porous media

A three-dimensional hierarchical finite element formulation of Biot's equat ion for low frequency elasto-acoustic wave propagation in fluid saturated p orous media based on a weak formulation with fluid displacement and solid d isplacement as dependent variables is presented. A global error measure for evaluation of the convergence is proposed. Numerical simulations of an air saturated polyurethane foam material show faster convergence for the hiera rchical extensions than for linear and quadratic serendipity finite element mesh refinement extensions. (C) 2001 Academic Press.