Modeling and analysis of truck tire-terrain interaction

Abstract

One of the key factors for improving the mobility and operating efficiency of trucks is the understanding of the tire-terrain interaction characteristics. Due to the broad range of terrains that trucks may operate over, the understanding process of the tire-terrain interaction is necessary. The terrains for on-road operations are commonly dry or wet surfaces. For off-road operations, a more extensive range of deformable terrains exists, such as dense sand, clayey soil, and gravel. In some cases, vehicles may operate over terrains covered with snow or layers of mixed snow and ice. This research work focuses on modeling and investigating the tire-terrain interaction on several terrains to better predict off-road truck performance. The truck tire used in this research is the off-road Regional Haul Drive (RHD) size 315/80R22.5 drive tire. The truck tire is built node-by-node using Finite Element Analysis (FEA) technique and is validated using different dynamic and static tests that are compared to the manufacturer's measured data. The terrains are modeled and calibrated using the Smoothed-Particle Hydrodynamics (SPH) instead of the classical FEA technique. Furthermore, two soil moisturizing techniques are presented to model moist soils, the virtually calibrated moist sand is validated against physical measurements. The in-plane and out-of-plane rigid ring tire model parameters are calculated for the off-road tire running on various terrains. The tire-terrain interaction is performed under several operating conditions and the effect of the operating conditions are investigated. Furthermore, a detailed study of the rolling resistance coefficient prediction over different terrains is presented. In this research work, the hydroplaning phenomenon is investigated. The hydroplaning speed of the tire is computed under different operating conditions. A novel equation to predict the truck tire hydroplaning speed as a function of several tire operational parameters is developed and validated against an empirical equation. In addition, the rigid ring tire model is integrated into a highly advanced full vehicle model to predict the truck on-road and off-road performance. Nonetheless, in order to validate the simulation results of the truck tire-terrain interaction obtained in this thesis physical testing was carried out in Gothenburg, Sweden by Volvo Groups Truck Technology.