posted on 2014-12-15, 10:37authored byDaniel William. Davey
This thesis describes an engineering methodology which has been applied to design a soccer shin pad to reduce the incidence of tibial feature within the game of football. By extrapolating statistics detailing the cause of tibial fracture within the County of Leicestershire it is estimated that approximately 3000 footballers sustain a broken leg each year in the UK. The vast majority of fractures are 'low energy' and result in the formation of a single crack in the tibia. This demonstrates that the redesign of shin pads has potential to reduce the number of fractures for even a relatively small decrease in loading during the impact event. An experimental test rig has been developed with an impacting mass and geometry that simulates a football tackle. This test method significantly improves on previous investigations by including a pressure sensing array between the padding materials and synthetic leg. Preliminary experimentation demonstrated that for a two layer system, consisting of a stiff outer shell with a foam substrate, subjected to an impact of fixed mass and velocity, there must be an optimal material combination which provides the minimal peak load on the leg, and therefore reduces the probability of tibial fracture as a result of impact. These experiments provided useful data for a combination of prospective materials for impacts of low velocity. To achieve realistic impact velocities, computational Finite Element Analysis (FEA) has been used. Analysis was carried out by applying non dimensional groupings, derived for text book theory to experimental and FEA results. This led to a definitive equation that allowed the characteristics of an impact, typical of a football tackle, to be predicted. Using this equation, materials were selected to manufacture a prototype, which was subsequently put through a rigorous test regime.