Discrete Element Modeling of Pavement-Wheel Frictional Force

Abstract

Frictional force is a primary force on the pavement surface in the horizontal direction and its value may be impacted by many factors such as properties or characteristics of pavement and tires, speeds, acceleration, and deceleration of running vehicles, and damping properties at the interaction surface. This paper presents a numerical approach to quantify impacts of vehicle motion features (acceleration, steadily moving, and deceleration) on pavement fractional force. In order to minimize impacts from the other factors, an idealized discrete element model was used. The idealized model consisted of three parts: a smooth surface simulated the pavement surface, while the truck was modeled with a wheel and a mass. Three contact models were employed to simulate the mechanical behaviors at the interaction surface, namely an elastic contact model, a slip model, and a viscous contact damping model. A vertical force and a torsion moment were applied at its center and the wheel was rotated forward to simulate the wheel-pavement interaction. Through this study, it was found that 1) during the wheel moving, the frictional force was not constant but vibrating around its average value; 2) the average frictional force was close to zero during the wheel steadily moving, while it was non-zero during its acceleration and deceleration; 3) damping coefficient and peak rational velocities gave various effects on simulation results.