A New Mathematical-Physical 2D Tire Model for Handling Optimization on a Vehicle

This paper introduces and discusses a new 2D physical model which has been developed and validated in order to study and optimize the handling behavior of the tire. It can be divided into two parts, the structural model and the contact area model. The parameters, that are function of the vertical load, are identified or calculated by comparison with the results provided by 3D finite element models. The input data for the identification procedure consist of a set of frequency responses performed on the finite element model. A second set of simulations on the 3D model of the tread pattern gives the characteristics of the contact model. Once built the 2D model it is easy to carry out both steady state and transient analysis. The steady state analysis returns the cornering carpet, in terms of lateral force and self-aligning moment as function of the cornering angle. The transient analysis allows the evaluation of the relaxation length and dynamic characteristics. The physical model can be embedded in the vehicle model. Since the parameters are function of the vertical load it is possible to perform any kind of manouvre simulation that implies load transfer between the axles such as overtaking, changing of lane and steering pad at growing speed. As a consequence the 2D model can be seen as a powerful tool to optimize the tire through a sensitivity analysis performed with tire and vehicle models linked to each other.