Hybrid Computational Tire-Sand Interaction: A Tractive Effort and Rolling Resistance Analysis

This paper investigates the performance of a computational radial passenger car tire over winter road sand at different operating conditions. An experimental direct shear-strength test was conducted using winter road sand to obtain the density, internal friction angle and cohesion. A simulated direct shear-strength test was then validated in a Finite Element Analysis (FEA) software called Virtual Performance Solution (VPS) using a Smoothed-Particle Hydrodynamic (SPH) technique to model the sand. Once the sand was validated against physical testing data the sand was layered atop an icy road surface to understand the influence sand has on tractive effort and rolling resistance performance. With modelled and validated winter road sand and a Continental CrossContact LX Sport tire size 235/55R19, testing conditions were set up. The tire-sand interaction was simulated using a node-to-segment contact algorithm with edge treatment on a low friction surface for both the tire-road and the sand-road contact. Using testing conditions of 57 mm, 114 mm and 170 mm sand depth at 10 kph, 50 kph and 100 kph and at 3.5 kN, 5 kN and 8 kN loading on a low coefficient of friction rigid road surface the tractive effort and rolling resistance were computed and analyzed. The goal of this research is to understand the influence that abrasives, such as sand, have on the tractive effort and rolling resistance of vehicle tires in winter conditions. By understanding the tire-sand interaction, this paper provides information on which operating condition is best suited to manage icy road conditions without compromising the environment.