Dynamic Deformation Measurement of a Golf Ball during Normal Impact

The normal impact between a golf ball and a rigid steel target was studied using a high-speed video camera. Video images recorded before and after impact were used to determine the inbound and rebound ball velocities, the contact time, and the coefficient of restitution. The images during impact were also employed to analyze the deformation of the ball. The normal and lateral compression ratios of the ball were measured as a function of the inbound velocity. The result showed that the contact time and the coefficient of restitution decreased with the inbound velocity, while the opposite relation was obtained for the normal compression ratio. Displacement at the center of the ball was measured during impact to determine the instantaneous ball velocity and acceleration. Reaction force was evaluated by the product between the mass and acceleration of the ball. It was found that the force increased linearly with the inbound velocity.