Tire Characteristics Sensitivity Study

Abstract

Tires are the main contact between a vehicle and the road. Tire modelling for full vehicle simulations is a challenge due to tires' non-linear behaviour and strong coupling between their different degrees of freedom. Several approaches for tire modelling with regard to handling are available. Empirical models such as Magic Formula fitted to test data are the most widely used. The aim of this thesis is to find an alternative tire model with relatively few parameters that are physically meaningful and hence suitable for parametric sensitivity studies. The model should also be representative of tire behaviour by an acceptable fit to tire test data. A survey of applications of tire models and suitable parameters for sensitivity analysis has been performed within Volvo cars with focus on handling. Simultaneously a literature study has been done to identify and categorize available tire models. TMeasy was chosen to be used in the parametric sensitivity studies. This semi-physical tire model fits to test data relatively well and is based on fewer parameters compared to the Magic Formula. The main reason for the selection of TMeasy is that the parameters describing the model, represent tire characteristics that were identified in the application survey as target parameters for sensitivity analysis. The effect of tire parameters on vehicle handling characteristics have been investigated by implementing TMeasy in Adams/Car and performing full vehicle simulations.