A novel stabilized NS-FEM formulation for anisotropic double porosity media
Computer Methods in Applied Mechanics and Engineering, 401:115666, 2022.
Summary
The paper develops a coupled description of deformation and fluid transport in anisotropic materials with two interacting pore systems. Macroscopic poroelastic coefficients are derived from the intrinsic properties of the constituent single-porosity materials, and the momentum contribution associated with fluid exchange is evaluated. Calculations for sandstone provide a comparison with established parameter estimates. The resulting equations are implemented using a node-based smoothed finite element formulation. Numerical stability is improved by distributing several stress points across each smoothing domain and applying polynomial pressure projection. Four benchmark problems are used to check the implementation against reference solutions and assess the scope of the anisotropic formulation. Further simulations examine elastoplastic behavior, focusing on permeability directionality, differences in permeability between the pore systems, and strain softening. The combined theoretical and computational framework offers a means of representing both material anisotropy and the interaction of distinct storage and transport networks.