The 2014 conference of the International Sports Engineering Asso ciation Effect of varying the volume infill sand on synthetic clay surfaces in terms of the shoe-surface friction

Abstract The friction developed by the shoe -surface interface on artificial clay has not been widely studied, and ca n influence player’s performance and injury risk. The aim of this research was to investigate the effect of varying the quantity of infill sand on shoe-surface friction on an artificial clay court tennis surface. A laboratory-based mechanical test rig was used to measure the friction force developed at the shoe -surface interface. Additionally, the perception of a group of participants, performing a turning movement on the same surface under dry conditions, was collected in order to compare against the mecha nical results. The relationship between the normal force and friction generated by the shoe-surface interaction was examined for surfaces with different sand in-fill volumes. The mechanical testing was performed un der dry and wet conditions, showing strong and significant differences. Results indicated that the normal force significantly influenced the static and dynamic frictional forces. For lower sand infill volumes, as normal loading increased, the dry condition was found to exhibit the lowest peak static friction force and highest average dynamic friction force. Howe ver, for higher sand infill volume conditions, the op posite behaviour was observed. Strong and significant positive linea r relationships were found between peak friction fo rce and average dynamic friction force for all infill sand volumes and conditio ns. The mechanical results were in agreement with the perception data, which suggests that the participants were sensitive to the small changes in sand infill volumes.The findings of this study will therefore aid the u nderstanding of tennis players’ perceived response to a tennis court surface. In order to get a better understanding of friction behaviour, further testing needs to be performed, and once the mechanisms involved are understood, surface properties could be modified to increase performance and reduce injury risk. © 2014 The Authors. Published by Elsevier Ltd . Selection and peer-review under responsibility of the Centre for Sports Engineering Research, Sheffield Hallam University.