The grip of motorsport surfaces

Abstract

The following thesis is a body of work carried out over a six year period. The purpose of the work is to better understand racetrack grip. Research of this nature has never been conducted into evaluating the role of surface material as a component of grip in a racetrack environment. As such, this thesis is unique. This is highlighted through a rigorous literature review that emphasises the lack of academic research into the materials the makeup racetrack surfaces. Discussions with motorsport industry figureheads and governing bodies such as Federation Internationale De l’Automobile (FIA), Formula 1 (F1) and F1 teams confirmed that little is known about the surface aspect of the tyre/surface interface.

An evaluation of literature utilising existing skid resistance/grip testing methodologies commonly used on roads and airports indicated the potential benefits of using GripTester for evaluating the variation and evolution of racetrack grip. A micro GripTester push device was selected for focused grip testing and Close Range Photogrammetry (CRP) was shown to have the ability to create in-depth surface models to infer micro and macro roughness parameters.

A method for measuring racetrack grip, known as GripMap, is outlined. The process involves measuring wet grip over an entire track by completing multiple full laps at metre increments across the width of the track. This generates large datasets ranging from 20,000 to 80,000 discrete measured grip data samples. The Global Positioning System (GPS) stamped grip data can then be analysed as a whole using techniques such as cumulative frequency analysis or visualised as a map. The grip data can be created into a detailed GripMap using software such as Esri AcrGIS. This can be queried and analysed using colour threshold classifications to highlight features in the data such as the racing line, surface material changes, surface treatments and the build-up of contaminants such as rubber.

Unparalleled access to live top level motorsport events allowed for the selected process to be implemented during F1 and British Tour Car Championship (BTCC) events. The resultant data shows the ability of the GripMap system to capture variation and evolution of grip. The formation of the racing line, effect of rain on a track surface, effect of surface treatments, highlighting low grip materials and evolution of grip is visible in the GripMap analysis. The benefit of focused grip evaluation surveys using a micro GripTester is illustrated. Smaller GripMaps can be created to measure grip in areas of interest that could help improve vehicle performance or prepare a racetrack for an event. A combination of the three methodologies provided a strong basis for analysing racetrack surfaces and variation in grip.

The 3D surface models created using CRP in this thesis produces significant findings. Analysis suggests that the enveloping of surface by an F1 tyre can be inferred using CRP. Surface models produced showed that the surface penetration of a F1 tyre at the Singapore Grand Prix 2017 and Singapore Grand Prix 2018 was 1mm and 1.8mm respectively.

This study and its findings suggests a set of conclusions and recommendations. Findings including detailing methodologies for measuring racetrack grip. This can be used for motorsport teams to improve performance and improving simulations. The opportunity to improve safety in motorsport through the creation of a homogenised approach to racetrack surfaces is discussed. A governing standard for racetrack surfaces and the adoption of the GripMap process as a tool for surface quality evaluation is recommended. The utilisation of the methodologies outlined in this thesis could improve the standard of racetrack surfaces and offer governing bodies the ability to assess surfaces before events for the improvement of safety standards.

Date of Award	May 2019
Original language	English
Supervisor	David Woodward (Supervisor)