Addressing the limited predictive capabilities of tyre models by enhancing understanding on how to transfer tyre shear force characteristics from one road surface to another

Please note that this is an Engineering Doctorate and not a PhD - you will be based at the sponsor premises for around 80% of the project time. The sponsor is Jaguar Land Rover, Gaydon site in Warwickshire.

Background:
Due to insufficient fundamental understanding of tyre-road interaction, current tyre models used for vehicle simulations have very limited predictive capabilities and, thus, only work reliably within the experimentally tested conditions – which represent only a narrow range of real driving scenarios. At present, the common approach to deal with different operating conditions is either to ignore relevant influences (e.g., thermal characteristics of rubber) and/or to simplify the problem by adjusting approximate scaling factors (e.g., a global friction coefficient to simulate different road conditions). Considering the recent advances achieved in the simulation of vehicles (e.g., full vehicle simulator) the restrictions arising from current tyre model limitations have become more apparent and a clear need for improved tyre models exist.

Aim and objectives:
The aim of the project is to enhance understanding on how to transfer tyre shear force characteristics from one road surface to another in order to address the limited predictive capabilities of tyre models. The new insights will be achieved through three main technical objectives:

1) Characterisation of:
- material properties of tyre rubber
- road surface roughness down to micro-scale
This part will primarily be carried out using facilities at the University of Surrey.

2) Experimental investigation of:
- tyre rubber friction on different road surfaces
- full tyre characteristics (including rolling resistance) on different road surfaces
This part will be carried out using facilities at the University of Surrey and JLR.

3) Development of a model/methodology to transfer tyre characteristics between different road surfaces.

Capacity of sponsoring institution:
JLR has extensive experience in tyre characterisation and the necessary capacity to support the experimental and simulation part of the project. For instance, a fully instrumented test vehicle is available that allows recording of tyre forces while driving. Also, collaborations with tyre testing facilities (e.g., Calspan) exist which allow obtaining experimental tyre data on a state-of-the-art rolling road test bench.