Recent advances in mixed finite element approximation for poroelasticity

Overview

Abstract

Linear poroelasticity models have important applications in biology and geophysics. In particular, the well-known Biot consolidation model describes the coupled interaction between the linear response of a porous elastic medium saturated with fluid and a diffusive fluid flow within it, assuming small deformations. This is the starting point for modeling human organs in computational medicine and for modeling the mechanics of permeable rock in geophysics. Finite element methods for Biot’s consolidation model have been widely studied over the past four decades. In the first part of the talk, we discuss posteriori error estimators for locking-free mixed finite element approximation of Biot’s consolidation model. The simplest of these is a conventional residual-based estimator. We establish bounds relating to the estimated and true errors and show that these are independent of the physical parameters. The other two estimators require the solution of local problems. These local problem estimators are also shown to be reliable, efficient, and robust. Numerical results are presented that validate the theoretical estimates and illustrate the effectiveness of the estimators in guiding adaptive solution algorithms.
In the second part of the talk, we discuss a novel locking-free stochastic Galerkin mixed finite element method for the Biot consolidation model with uncertain Young’s modulus and hydraulic conductivity field. After introducing a five-field hybrid variational formulation of the standard Biot consolidation model, we discuss stochastic Galerkin mixed finite element approximation, focusing on the issue of well-posedness and efficient linear algebra for the discretized system. We introduce a new preconditioner for use with MINRES and establish eigenvalue bounds. Finally, we present specific numerical examples to illustrate the efficiency of our numerical solution approach. Finally, we discuss some remarks related to the non-conforming approximation of Biot's consolidation model.

Brief Biography

• Ph.D. (Mathematics), Indian Institute of Technology (IIT), Kanpur, UP, India, CPI. Title-Nonconforming Least-Square Spectral Element Method for Parabolic Partial Differential Equation with Non-Smooth Data and Application to finance
• Post-doctoral fellow, The University of Manchester, Manchester, UK
• Post-doctoral fellow, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany