Finite element study of energy absorption foams for headgear in football (soccer) games

摘要

A validated anatomical finite element head model is used to simulate a scenario of front-rear head impact in football games. The impact responses of the two heads are obtained to assess head injury risks. It has been shown that when the impact velocity v = 2.5/s the possibility of inducing moderate injury is high and that for server injury is low. However, when the impact velocity v ≥ 4/s, the risks of both kinds of injuries are nearly 100%. Consequently, headgear made from energy absorption foams is used in football games to protect the players' heads. The results show that for expanded polypropylene (EPP) foam headgear the optimum thickness is between 8 and 12 mm. In addition, the use of carbon nanotube (CNT) containing foam is proposed for headgear. The effectiveness of CNT foam as headgear is evaluated and compared with that of traditional foams, i.e., EPP and expanded polystyrene (EPS). When impact velocity v ≤ 4/s, all these foams with the density of 63 kg/m~3 and the thickness of 8 mm can provide effective protection. CNT foam shows the most effective protection in two-head impact, due to its high energy absorption capacity and excellent property of being recoverable.