Hybrid method for assessing the performance of sports surfaces during ball impacts

Predicting the behaviour of sports surfaces during ball impacts can be extremely complex, especially if both the surface and the ball are made up of combinations of materials that behave non-linearly. This study uses a hybrid approach of experimental measurement and mathematical modelling to predict the performance of sports surfaces in real impact situations. An impact hammer system was first designed and developed, which is capable of accurate field testing and provides data to form model parameters for a variety of sports surfaces (e.g. tennis court, cricket pitch). A mass-spring-damper model of a deformable ball impacting on a rigid surface was then combined with a model of the rigid hammer-surface impact to form a two degre-of-freedom model of a deformable ball impacting on a deformable surface. Model predictions were independently verified using high speed video measurements of cricket ball-pitch impacts, and a good agreement was found. This hybrid approach provides parameters to categorize a surface and predict impact performance.