Component-Level Finite Element Model and Validation for a Modern American Football Helmet

Abstract

Epidemiological data and measurement of biomechanical data collected through physical experiments have contributed to the understanding of potential head injury risk in contact sports such as football. Further improvement of protective helmets requires repeatable conditions and detailed parametric studies that may be addressed in part using the Finite Element (FE) method. However, such an approach requires thorough experimentation and validation of the helmet materials and subcomponents, which previous studies do not fully address, prior to implementing these subcomponents in a full helmet model. Development of a modern football helmet FE model requires a bottom-up approach, focusing on material testing, constitutive models and subcomponent-level validation, which has not been fully addressed in the literature to date. Material samples were extracted from a modern football helmet including the helmet shell, energy-absorbing structures, comfort foam, and strap system. The subcomponents were tested across a range of quasi-static and high deformation rates relevant to football impact scenarios. FE models of the subcomponents were developed and validated, focusing on verification of material behaviour, representative loading conditions, and mesh convergence to achieve realistic responses and increase computational efficiency. Evaluation of the FE models comparing experimental with simulated responses, yielded good to excellent CORrelation and Analysis (CORA) ratings of 0.954–0.985, 0.931, 0.937–0.974, and 0.847–0.958 for the helmet shell, facemask, energy-absorbing structures, and comfort pads, respectively. The resulting validated subcomponent-level models provide an important foundation for integration into a full helmet model to ultimately optimize performance and reduce head injury.