A comparative study on the mechanical performance of the protective headgear materials to minimize the injury to the boxers’ head

This study was aimed at performing a dynamic Finite Element (FE) study to compare the performance of three different materials, i.e., the expanded propylene (EPP), expanded polystyrene foam (EPS), and polyvinyl alcohol sponge (PVA), in reducing the amount of injury as a result of a right hook to the face. To do that, a well-verified FE model of the skull, headgear, and punch was employed to simulate the hook in the zygomatic bone of the skull and the resulted von Mises stress in that under three different energy absorbing headgear materials were calculated. The mechanical properties of the EPP were obtained from the literature, while the mechanical properties of the PVA and EPS were measured by the authors. The mechanical properties of the EPS were measured under six different strain rates, and the mean mechanical values were assigned to the model. The experimental results revealed the values of 0.44 ± 0.084 (MPa), 1.47 ± 0.087 (MPa), 0.98 ± 0.11 for the elastic modulus, stress and strain failures, respectively. The numerical FE results showed the von Mises stress of 11210 MPa as a consequence of hook in the skull. After wearing the headgears, the stresses of 364.40, 640.3, and 79.34 MPa were observed for the EPP, PVA, and EPS, respectively. The results suggest the effectiveness of the EPS compared to two other materials in controlling the amount of injury in the face of the boxers. Finally, a composite structure of these three materials were employed which enabled to lessen the stress in the face to 30.56 MPa.