Finite Element Modeling of Tire-Terrain Interaction

摘要

The desire to incorporate theoretical mechanics into off-road vehicle performance prediction has generated great interest in applying numerical modeling techniques to simulate the interaction of the tire and terrain. Therefore, a full three-dimensional model simulating a tire rolling over deformable terrain was developed. Tires were simulated using a rigid wheel, a deformable tire simplified with user-defined sidewall elements, and modal analysis tire models. Model comparisons with measured, hard-surface tire deformation and contact stress showed very good agreement. The simplified tire model was much more computationally efficient but the modal analysis model yielded better contact stress distribution. Each of the tire models was then combined with rolling on deformable terrain. Fresh snow and compacted sand surfaces were modeled using critical-state plasticity models. The rigid wheel model was validated on snow using field measurements of tire forces and snow deformation and then compared to performance predictions using the NATO reference Mobility Model. These comparisons indicate excellent agreement between the model and the measurements. Preliminary results of the modal analysis tire model on snow show very little deformation in the tire, indicating that the rigid wheel simplification may be a good approximation for soft terrain.