Prediction of vehicle mobility on large-scale soft-soil terrain maps using physics-based simulation

A high-fidelity physics-based approach for predicting vehicle mobility over large soft-soil terrain maps is presented. The approach is based on an HPC design-of-experiments (DOE) procedure, and the integration of multibody dynamics for modelling the vehicle and the discrete element method (DEM) for modelling the soil into one solver. A general cohesive soil DEM material model is used which includes the effects of cohesion, elasticity, plasticity/compressibility, damping, friction, and viscosity. To manage problem size, a novel moving soil patch technique is developed in which DEM particles which are behind the vehicle are continuously eliminated and then reemitted in front of the vehicle, levelled and compacted. The DEM inter-particle cohesion and friction are calibrated to the cone index using a simulation of a cone penetrometer. The DOE approach is demonstrated by predicting the speed-made-good distribution on 22 × 22 km terrain map for a 4 × 4 military vehicle. Two terrain parameters are considered in the DOE: terrain positive slope and soil strength.