A Study on the Effect of Tire Temperature and Rolling Speed on the Vehicle Handling Response

Rubber is a non-linear viscoelastic material which properties depend upon several factors. In a tire two of these factors, namely the temperature and excitation frequency, are significantly influenced by the vehicle operating conditions. In the past years, applied research studied how rubber viscoelastic characteristics affect structural and frictional tire properties. The present study focuses on how these effects interact with the vehicle handling response. Based on state of the art theory of friction, structural properties of rubber and on experimental evidence, the dependency of key tire parameters on temperature and rolling speed is established. These results are then used in combination with a single-track vehicle model to assess their impact on key vehicle parameters; as an example, the understeer coefficient, yaw resonance peak / damping and maximum acceleration are studied. Furthermore, to ensure accurate results in realistic situations, a novel tire thermodynamic model is used in combination with a detailed 14 degrees of freedom vehicle model in a numerical simulation environment. The simulations permit to study the mutual effects between tire temperature, rolling speed and vehicle dynamics. Quantitative figures are given that determine the impact on the specific vehicle handling parameters in different operating conditions. It is finally concluded that, in most cases, a higher tire temperature and / or higher rolling speed results in a degradation of the vehicle handling response.