On the Determination of Coordination Numbers of Coupled DEM-DFN Model for Modeling Fractured Rocks

Natural fractured rocks usually contain background granular media and multi-scale fractures. The coordination number is a crucial factor to characterize the connection of microstructural elements. On the determination of coordination numbers for modeling fractured rocks is important to interpret micromechanical properties. We have built a consistent workflow of discrete element models (DEMs) coupled with discrete fracture networks (DFNs). This DEM-DFN model could provide a simple formulation for high calculation efficiency to model a more realistic and detailed description of fracture system. A series of numerical experiments are set up, aiming to correlate window radius, nodal spacing, and crack length, which will benefit the window selection for measuring coordination numbers based on the crack characteristics. DEM-DFN modeling of the coordination numbers determined coordination number has the potential for numerical upscaling from the microstructural responses to the macroscopic properties of fractured rocks and identifying crack patterns in the spatial distribution.