A Novel Wheel-Soil Interaction Model for Off-Road Vehicle Dynamics Simulation

This work establishes a semi-empirical wheel-soil interaction model, developed in the framework of plasticity theory and equilibrium analysis, to be used in vehicle dynamics simulations. Vehicle-terrain interaction is a complex phenomena governed by soil mechanical behavior and tire deformation. The application of soil load bearing capacity theory is used in this study to determine the tangential and radial stresses on the soil-wheel interface. Using semi-empirical data, the tire deformation geometry is determined to establish the drawbar pull, tractive force, and wheel load. To illustrate the theory developed, two important case studies are presented: a rigid wheel and a flexible tire on deformable terrain; the differences between the two implementations are discussed. The outcome of this work shows promising results which indicate that the modeling methodology presented could form the basis of a three-dimensional off-road tire model. In an off-road three-dimensional tire model, the traction behavior should include shear forces arising from the surface shear with the soil as well as the bulldozing effect during turning maneuvers.