A multiscale framework for modeling geomaterials

The macroscopic behavior of granular materials is encoded in their grain scale. Traditional continuum-based methods generally lack the capability to capture the underlying physics of particle interaction that is especially important for applications near failure regimes. Discrete mechanics methods, like DEM, are naturally suitable for modeling granular media. However, full-scale computation using these methods is typically limited by a deficit of computer power. Solving this dichotomy demands development of multiscale methodologies in geomechanics. This paper presents a multiscale framework using the concept of unit cell for granular material simulations. The basic idea is to select key parameters, like the dilatancy and friction from the unit cell computation, to inform the continuum formulation on the fly. It is shown, by way of numerical computations, that this novel scheme is capable of accurately capturing complex behavior of granular materials. This framework is open to extension in the sense that it is not limited to a specific continuum model and is able to accommodate any type of grain-scale method.