Large scale discrete element modeling of vehicle-soil interaction

This paper describes the current work on a large deformation soil model to demonstrate the feasibility of particle models to simulate full-scale vehicle-soil interaction problems in which the soil undergoes large excavation-like deformation. To achieve this objective, boundary conditions that accurately represent the vehicle geometry had to be incorporated into a 3D discrete element model. The approach taken was to use a finite-element grid to model the vehicle component interacting with the soil and develop routines to model the particle-grid interactions. The particle-grid interactions were more complicated than the particle-particle interactions required for the soil simulations and pose the greatest challenge to the use of computational parallelism. Two examples are presented in which vehicle components are modeled by finite elements that interact with 10 million discrete soil elements. Important theoretical issues are briefly noted concerning mechanics of granular media that are critical to acceptance of the nascent discrete element modeling technology.