Toward Ambient Armor: Can New Materials Change Longstanding Concepts of Projectile Protection?

Abstract

Materials that protect against the high strain rate loading of a projectile have traditionally been constrained by their use on the target of protection. Here the possibility of new materials, particularly carbon nanocomposites, are explored for projectile protection removed off of the target and placed along the trajectory at an intermediate location. A mathematical model of such Ambient Armor (AA) separates the impact, capture, and energy dissipation of an incident projectile into each of three stages, respectively. A distinct scaling of the projectile to composite area ratio and areal density ratio is derived for a given requisite stopping distance. As an example, the model predicts that a 1 g and 800 m s 21 small projectile could be decelerated to 3 m s 21 within 6–9 m using a 2.34 3 10 4 layer monolayer graphene nanocomposite at 0.02 volume fraction. For larger projectiles with higher kinetic energy, a tandem system using a second composite body with the specified area density is explored with the idea of making the projectile gyroscopically unstable for rapid deceleration and subsequent interception. Off target reinforcement or AA may in general allow for the exploration of a broader range of material properties for projectile protection.