Identification of the ball's roll and slide behavior during soccer kicks

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024)

Kicking a soccer ball and imparting spin on it is a complex action. Ishii et al. (2014) evaluated the interaction between shoe and ball in a finite element model and concluded that a low coefficient of friction (COF) of 0.2 results in sliding between the ball and shoe, and that varying the COF has no effect on the angular velocity of the ball. The latter result is mechanically counterintuitive, since the COF when kicking a stationary soccer ball is proportional to the ratio of angular to translational velocity. Kimachi et al. (2018) identified the contact point between the shoe and the ball but did not address the COF. The aim of this study is to investigate the rolling and sliding behaviour between the shoe and the ball by using the helical axis (HAX) method. The hypothesis of this study is that when the ratio of friction to normal force is sufficiently large, the ball rolls with respect to the shoe and the HAX will be in the contact area of. When the ratio of friction to normal force is small, the shoe slides against the ball and the HAX moves away from the contact point.