Abstract:
This work addresses the problem of tyre tread pattern design for
optimum wet grip performance.
A mathematical model of tyre behaviour on wet roads has been
developed. This utilizes the finite element method in the
representation of tread pattern geometry. The performance of a
particular tread pattern is found in terms of the fluid pressures
and film thicknesses existing within the contact patch, under wet
conditions.
Many modern tread patterns are based on 'blocks', and a computer
model has been developed specifically to assist the tyre designer
in the design of these blocks for improved wet grip. Numerical
results are presented both for complete contact patches and for
individual tread blocks. To allow the use of the computer models
by the tyre designer, with no specialist knowledge of the finite
element method, special purpose mesh generation and plotting
programs have been developed.
Experiments have been undertaken whereby the fluid pressures and
film thicknesses existing in the tyre contact patch have been
measured under high speed conditions in the wet. These measure-
ments were made on an indoor testing machine, and the techniques
developed can be used in the routine evaluation of tyre wet grip
performance. Some results of experiments performed on plain and
simple patterned tyres are presented.
The main purpose of this work was the development of the
mathematical models which can be used for future research into,
and design of, tyres for improved wet grip. However, some
conclusions are made as to possible features which could be
utilized in future tyre designs.