Numerical Mechanical Design of a Football Helmet to Dissipate Energy Through Finite Element Failure Technique

American football is currently the most popular sport since it is practiced all over the world, from the infantile to professional category. However, being a contact sport, the injury that occurs with a high probability is a head concussion. It is estimated that each year more than 300,000 persons experiment a head concussion occurring to college and professional football players. For a player to have a head concussion a helmet to helmet collision must occur. Over the years, finite element analysis has been successful to evaluate and determine structural damage, and possible consequences for biological tissues. Numerical analysis of helmet impact necessary involves the application of multidisciplinary sciences where the interaction of sudden acceleration and deceleration occurs. The interest of this research arose in developing a numerical biomechanical model of a Speed Flex helmet (which Ridell company opened to the commercial market in 2018), and it is widely used worldwide. Initially, a CAD program is applied to develop the numerical model of a commercial helmet focusing on the possible implementation of geometry changes to reduce the high risk of concussion index. Nevertheless, the evolution of the study has not had enough progress, because there are too many variables involved in the problem. To satisfy and be able to perform the numerical analysis adequately, it was only considered the helmet evaluation against frontal impact. Subsequently, in the present work, a proposal of composite materials is implemented, which have enough impact resistance, corrosion resistance, and wear resistance, so players will be more secure against concussions. Composite materials have a better ductile modulus of elasticity and mechanical resistance per unit weight. For this reason, it is proposed to implement this technology into the Speed flex helmet. The idea is to preserve the helmet geometry, and with the data obtained from previous analyses, perform a new analysis (under the same conditions) to observe the behavior of a Speed helmet. The Speed helmet has a modification to its geometry, where a hexagon form is implemented that acts as a cantilever beam in the front of the helmet to dissipate the consequence of impact energy. This kind of hexagon cantilever beam, when the helmet collides receives the impact energy and tends to bend or produce a crack or break, transforming this energy into strain or deformation, reducing concussion risks. Finally, a comparison of numerical analysis data in the three case studies is shown. This type of numerical analysis allows us to observe the behavior of each helmet and how the impact energy dissipates, determining the helmet areas most susceptible to producing a concussion.