Analysis and optimisation of tires for passenger cars

Practically since the beginning, but especially during the last decade, automotive companies have to face a highly competitive market characterised by constant demand for innovation, and for reduction of product development time and costs. Moreover, they have to meet best customer needs of different target markets, keeping in mind new technological- as well as historical issues. To be more competitive, companies try to define already in the pre-development phase most of the vehicle’s parameters, according to requirements concerning comfort, ergonomics, and driving behaviour. The present thesis focuses on the driving behaviour, especially on the influence tires have on it. The aim of this thesis is developing a method for generating tires that have the desired physical attributes or the desired dynamics. To achieve this, in depth analyses (GSA and a developed Graphical-Numerical-Analysis) of characteristic values necessary to represent the tire and of objective-manoeuvre-criteria needed to evaluate their driving behaviour have been carried out. Two innovative tools have been developed: the Tire Shaper and the Tire Optimiser, both based on a genetic algorithm. The first allows to generate tires that have the desired physical characteristics; the second tunes these physical characteristics so that the tire has the desired dynamic behaviour, according to several manoeuvres. Case studies show the efficiency and power of the developed algorithms. The developed tools may support automotive companies during the pre-development phase to ac-quire a more comprehensive knowledge of how the physical attributes of tires should be in order to meet best the desired driving behaviour and subsequently to estimate the impact a change of the vehicle’s characteristics has on it.