Modeling Non-Penetrating Projectile-Helmet-Head Impacts for Helmet Evaluation

The project aims at providing a quantitative, methodological tool for a precise and comprehensive performance evaluation of helmets in military injury scenarios. A state-of-the-art three dimensional finite element biomimetic head model which includes skin, fat, skull, jaw, sinus, cerebrospinal fluid, brain, optic nerves, eyes, spinal cord, vertebrae and discs, was developed using ScanIP (Simpleware®, Exeter, UK) based on grey scale transversal cranial images from the Visible Human Project. The biomechanical properties of the tissues are based on the literature. A couple of ballistic helmet designs were added to the model with realistic measurements and mechanical properties. Then, a non-penetrating collision with a 5.56mm bullet (standard M-16 ammo) was modeled. Dynamic response of the helmet and all the head structures was simulated and the performance of each helmet was quantitatively evaluated and compared with other helmets, based on biomechanical metrics such as effective (von Mises) stress, speed, pressure and acceleration that developed in the intracranial tissues after the impact.