Using DEM-LBM for Micro-Scale Modeling of Coupled Hydro-Mechanical Processes in Geomechanics

Johnson, D. H., Vahedifard, F., Jelinek, B., & Peters, J. F. (2017). Using DEM-LBM for Micro-Scale Modeling of Coupled Hydro-Mechanical Processes in Geomechanics. Sixth Biot Conference on Poromechanics. Paris, France. 6, 238-245. DOI:10.1061/9780784480779.029.

The discrete element method (DEM) coupled with the Lattice Boltzmann Method (LBM) is emerging as a viable tool for modeling multi physics problems in geomechanics. By coupling two explicit solvers, the DEM-LBM model can be used as a robust and computationally efficient tool to model the micromechanics of coupled thermo-hydro-mechanical processes in granular media. In this study, a coupled DEM-LBM model is developed and used for micromechanical modeling of hydro-mechanical processes in various geomechanical problems. The DEM models the solid particle phase by treating each particle as a discrete rigid body, and the LBM solves the incompressible Navier Stokes equations. To demonstrate the capabilities of the DEM-LBM model, results are presented for two problems of a two-dimensional biaxial test on dilative material and shear thickening in a solid-fluid mixture. The biaxial test provides a study of the ability of the LBM to model pore pressure response based on the apparent compressibility of the immersed fluid. Comparison with the experimental test results showed that the DEM-LBM model is able to accurately model the shear thickening behavior of a suspension undergoing shear loading.