Granular materials are composed of many discrete, disconnected solid particles that come together to form a porous aggregate. These types of materials are ubiquitous in both natural and industrial settings, where they frequently interact with fluids in their local environments. Understanding and modeling these interactions is important for many industrial, civil, and geotechnical engineering problems, including applications in defense, mining, and construction.
In this work, we are particularly interested in modeling these materials during high-velocity impact events. In these types of events, it is necessary to consider how the deformation of individual particles affects the behavior of the bulk solid. Grain-scale elastic deformations determine the rate at which effective stresses and shocks are propagated through the material, and inelastic deformations (e.g., grain-scale fracture) affect how the grains organize themselves (i.e., the grain-scale microstructure). Additionally, the presence of a fluid saturating the pore space between grains can change the mechanics of grain–grain interactions (e.g., lubrication forces) and admissible granular motions (e.g., pore compaction or dilation).
Significant research in recent years has been devoted to developing models for dry, brittle granular materials that incorporate particle fracture and breakage; pore collapse and dilation; and shock loading into unified descriptions of these materials. However, there has not been substantial analysis of the fully-saturated condition outside of quasi-steady or dilute granular flows. In this work, we present a thermomechanical framework for modeling fluid-saturated, brittle granular materials that considers the coupled influence of particle breakage, pore evolution, shock loading, and pore fluid motion. A general form of this framework is presented alongside simulated results specific to silica-based sand mixing with water.