231 A fundamental study on impact force of soccer balls

Abstract

The purpose of this study is to analyse the dynamic effects of soccer balls and the differences impact forces have on these balls. The subject under discussion is the balls that have different material surfaces and panel orientations. We chose four balls for this research: Cafusa, Jabulani, Theam Geist2 and Pelias. These soccer balls have 32 panels, 8 panels, 14 panels and 32 panels. The experimentation used a Kick-Robot which reproduces the same speed and position to repeatedly impact the ball. We attached a dynamometer to this machine in order to measure the impact force. We experimented four pattern of speed: 15m/s, 20m/s, 25m/s, 30m/s. The results suggest that there is any direct correlation between a maximum of impact force and a number of panels. But, when the Cafusa is compared with other balls, the impact force of Cafusa has a lower than any other balls because of the soft material surface. In addition to this, under the all speeds, the impulse value of Jabulani always shows the biggest value compare with other balls. We suggest that Jabulani has a special structure and a special surface.