Locking-free finite element methods for poroelasticity

We propose a new formulation along with a family of finite element schemes for the approximation of the interaction between fluid motion and linear mechanical response of a porous medium, known as Biot's consolidation problem. The steady-state version of the system is recast in terms of displacement, pressure, and volumetric stress, and both continuous and discrete formulations are analyzed as compact perturbations of invertible problems employing a Fredholm argument. In particular, the error estimates are derived independently of the Lamé constants. Numerical results indicate the satisfactory performance and competitive accuracy of the introduced methods.