The Role of Friction and Tangential Compliance on the Resultant Launch Angle of a Golf Ball

A thorough understanding of how the delivered face angle and club path of a golf club influences the initial launch direction of a golf ball can play a significant role in the design of various club types as well as help players and coaches better understand performance in the field. A theoretical model based on a Hertzian impact formulation with the inclusion of tangential compliance via Coulomb friction is compared to empirical results. This comparison demonstrates that the initial launch direction of a golf ball for a given club path and face angle can be sufficiently predicted by the theoretical model, providing insights into the mechanisms leading to different launch direction percentages relative to face angle for various club types. Additionally, the relationship between launch direction and the coefficient of friction is explored for various angles of incidence.

Analysis of Impact-Induced Head Disk Interface Damage During Op-Shock

Hertzian impact theory is used to analyze impact-induced head disk interface (HDI) contact damage. Contact parameters including penetration (media damage), contact force, contact radius, impact duration, maximum and mean contact pressure are given at different normal impact velocities and slider corner radii in the form of contour plots. The results clearly suggest that the decrease of impact velocity or the increase of corner radius could both reduce the possibility of plastic deformation due to slider (head) disk impact contact.