ADVANCED TIRE-ICE INTERFACE MODEL FOR PNEUMATIC TIRE PERFORMANCE

摘要

Icy road conditions and tire operational parameters play a vital role in determining the overall performance of a vehicle. With the reduction of traction available at the road surface in icy conditions, the dynamics of the vehicle becomes more unpredictable, as the system can become unstable. Prior work in the Advanced Vehicle Dynamics Laboratory (AVDL) produced a Tire-Ice Model (TIM) aimed at estimating the coefficient of friction in the tire contact patch. The current work builds on that study, resulting in the Advanced Tire-Ice Interface Model (ATIIM). This model simulates the temperature rise in the contact patch based on the measured pressure distribution and the thermal properties of the tread compound and of the ice surface. This model allows a more thorough investigation of the tire-ice interface, being capable of simulating the height of the thin water film created from the melted ice, the prediction of tractive performance, the estimation of the viscous friction due to the water layer, and the influence of braking operations, including the locked wheel condition. Experimental studies were carried out at AVDL on the Terramechanics Rig. The experimental investigation included measuring the bulk temperature distribution in the contact patch in order to validate the temperature rise simulations of the ATIIM. As shown by both, the simulations and the test data, a rise in temperature was observed from the leading edge to the trailing edge of the contact patch. The rise in temperature can be quantified with respect to the load on the tire. As the wheel load increases, the difference in temperature rise increases, as also reflected in the experimental study. When the temperature difference was significant, a thin water film was observed and was also simulated using the ATIIM. This water film resulted in a reduction of friction, which was simulated in the ATIIM, as well as observed in the experimental studies.