On Mixed Isogeometric Analysis of Poroelasticity
For researchers in computational poroelasticity, this work offers a mixed isogeometric approach to mitigate pressure oscillations, but it is an incremental improvement over existing finite element methods.
The paper addresses pressure oscillations in poroelasticity simulations at small time steps by proposing a mixed isogeometric formulation. Numerical studies on Terzaghi's problem and layered consolidation show that the method alleviates oscillations, with comparisons to equal-order simulations.
Pressure oscillations at small time steps have been known to be an issue in poroelasticity simulations. A review of proposed approaches to overcome this problem is presented. Critical time steps are specified to alleviate this in finite element analyses. We present a mixed isogeometric formulation here with a view to assessing the results at very small time steps. Numerical studies are performed on Terzaghi's problem and consolidation of a layered porous medium with a very low permeability layer for varying polynomial degrees, continuities across knot spans and spatial discretizations. Comparisons are made with equal order simulations.