Complex Terramechanics for Mobility Assessment Part 2: Efficiency Through a Simple Terramechanics Representation

Abstract

Abstract The trade-off between computational efficiency and accuracy of various terramechanics simulation methods is a challenge that many engineers face when conducting analysis of off-road vehicle mobility. The Discrete Element Method (DEM) can capture complex phenomena within the soil, but requires substantial time and computing resources in comparison to the lower fidelity simple terramechanics methods such as the Bekker-Wong model. In this study, we propose a novel approach that seeks to strike a balance between efficiency and fidelity in simulating tire tractive capability in soft-soils. Our approach leverages DEM to determine Bekker-Wong parameters which encapsulate the bulk response of the DEM model and can predict accurate overall tractive performance. The process involves using DEM to generate soft-soil tire performance curves and using an optimization framework to determine simple terramechanics parameters, such as Bekker-Wong parameters, that best fit the DEM response. These parameters can then be used in other simulations for quantifying vehicle performance on soft-soil without the need for cumbersome DEM simulations. The results of the study demonstrate that the approach is promising with further refinement. Future work should focus on starting with more accurate DEM soil properties and scaling the method up to the full-vehicle level. If successful this work could ultimately provide a model with good predictive capability, while still allowing fast simulation times for agile design iteration and high run-count analyses.