Modeling Large Deformable Terrain With Material Point Method for Off-Road Mobility Simulation

Abstract In this study, a computational framework for the material point method (MPM) terrain model is developed for off-road mobility simulations to account for large granular terrain deformation in high-fidelity off-road mobility simulations. The Lagrangian finite element (FE) approach is not suited for modeling very large soil deformation due to mesh distortion, which causes element instability. Whereas the discrete element (DE) approach has gained acceptance in modeling complex granular material behavior, the computational cost is, in general, prohibitively high due to a large number of particles needed to describe not only the grain-scale material behavior, but also the macro-scale large soil deformation. Therefore, this study examines the use of MPM to model large deformable granular terrain in the context of off-road mobility prediction. To this end, MPM terrain models are developed and integrated into the off-road mobility simulation framework, leveraging high-performance computing. Furthermore, a contact modeling procedure for the FE tire and MPM terrain is developed, along with the moving soil patch technique generalized for the MPM terrain with the background grid. The MPM soil model is validated against test data, and its large deformation modeling capabilities are examined with several numerical examples.