Predicting the dynamic behaviour of cricket balls after impact with a deformable pitch

Dynamic measurements were taken from oblique impacts of cricket balls being fired at fast-medium pace onto simulated pitches made up of varying soil type. These were converted to performance characteristics, coefficients of friction and restitution, using a classical model of impact. This model was then modified to include deformation. Coefficients of restitution calculated from vertical ball impact tests were combined with the dynamic data to calculate modified performance characteristics that related to the effects of friction, restitution and deformation. Rebound angle data was split into two components, one due to restitution and friction, the other due to deformation. Measurements of bulk density and moisture content were found to compare more favourably with the modified performance characteristics than with the performance characteristics that ignored deformation. Linear relationships found between the modified performance characteristics and bulk density measurements from one testing session were used to predict results from another session using bulk density measurements alone. Predictions of velocity, angle and spin impact all fell within one standard deviation of experimental values.