Development of FEA wide-base truck tire and soil interaction models

Abstract

Tires are considered one of the most important components of ground vehicles as they are the only link between the chassis and ground. They support the vehicle weight and cushion road surface irregularities to provide a comfortable ride. Tires are designed in a way that provide necessary tractive, braking, and cornering forces to form a safe and stable ride for ground vehicles. Recent advancements in computerized and virtual modeling provided an efficient methodology for accurate prediction of tire characteristics. In this thesis Finite Element Analysis (FEA) is employed as a method to accurately construct a new virtual wide-base tire model, validate it, and then study rolling resistance of the tire on a hard surface. This thesis includes tire-soil interaction and effects of soil on tires rolling resistance. To accurately study rolling resistance on soft soil, various soil models are created by using FEA and Smoothed Particle Hydrodynamics (SPH), as a representative of dry sand soil. Soil models are calibrated by using shear-displacement and pressure-sinkage simulation tests. The simulation results are then compared to published data. Also, the created soil models are compared to each other to determine the optimum one based on computational time efficiency and accuracy. SPH, as the accurate current method for soil modeling, has long computational solving time. In this thesis FEA/SPH hybrid soil models are studied and modified to achieve lower computational solving time while having the desirable accuracy. Rolling resistance of tire on each soil model is carried out through various loads and inflation pressures and the simulation results are compared to physical test results to examine the accuracy of each soil model. The new hybrid soil model created in this thesis reduces the computational CPU time almost by half and slightly increases accuracy compared to full SPH soil model.