Linear Porous Media Theory through Variationally Consistent Homogenization

  • Kreutzheide, Phil (Chalmers University of Technology)
  • Larsson, Fredrik (Chalmers University of Technology)
  • Runesson, Kenneth (Chalmers University of Technology)
  • Jänicke, Ralf (TU Braunschweig)

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Theory of porous media has a long history in mechanics [1]. In this contribution, we establish a two-scale formulation for modeling deformation and seepage in porous media in the appropriately linearized setting. The macro-scale model is derived using a computational homogenization approach for a micro-scale Representative Volume Element (RVE) problem. More specifically, we consider one-way coupled fluid-structure interaction considering elasticity and Stokes flow, for the solid and fluid, respectively. This macro-scale model enables the determination of material parameters such as, e.g., drained elastic stiffness, permeability, and the Biot and Skempton (tensors) coefficients, numerically. While classical theory models the solid skeleton as a (micro-)homogeneous and isotropic material to derive effective parameters, this work extends the scope to account for the more general situation where the solid skeleton is heterogeneous and anisotropic. Numerical results illustrate how the microscale geometry and material constituents affect the effective parameters in the linear setting. In the case of a homogeneous solid skeleton, known results from the literature are recovered. Finally, we discuss geometric nonlinearities and possible solution strategies as an extension of the results. Here, the RVE problem needs to be solved concurrently with the macroscopic problem, since direct up-scaling is not possible.