DEVELOPMENT OF A TEST DEVICE TO MEASURE THE TRIBOLOGICAL BEHAVIOUR OF SHOE-SURFACE INTERACTIONS IN TENNIS

The aim of this thesis was to better understand the tribological mechanisms that occur during typical player movements, build further on this understanding and develop a robust, portable device to assess the friction characteristics of tennis surfaces that relate to playing performance and safety. To understand the tennis player’s response and adaptability to a tennis court surface, including friction in the shoe-surface interface, a series of friction experiments were carried out on three categories of tennis surface, grass, clay and hardcourt. For grass, parameters such as moisture, level of wear and height were found to have an effect on the shoe-surface friction. For clay, influence of clay particle size and the infill volume was established. In terms of biomechanical conditions, it was found that the shoe orientation during a slide affects the friction. It was demonstrated that matching applied pressures is a useful approach for shoe friction testing and analysis. Through video analysis, shoe landing and sliding were found to be two possible ‘risk’ movements. Material characterisation, combined with friction and temperature measurements have provided empirical knowledge into the manner in which shoes and surfaces behave. During a slide on hardcourts, temperature changes were found to be different along a shoe outsole. The front part experienced higher change of temperature compared to other positions. Three types of bespoke tread samples were produced and tested, resulting a ‘holed sample’ the optimal to use. These samples resulted relatively easy to manufacture and generate frictional results compared to tennis shoes. The final robust portable device resulting from this study, measures the friction characteristics of the shoe-surface interface representative of match-play tennis. The device can be used in two configurations to replicate a shoe landing and a sliding movement. The test shoe consists of a commercial rubber with a bespoke tread design with mechanical properties that match typical values to a tennis shoe. This device will aid the International Tennis Federation (ITF) and the sports surface research community to gain understanding of player-shoe-surface frictional interactions, and allow courts to be monitored around the world.