Ballistic Wave Propagation in Aramid Fiber Armor (2D)

When a bullet strikes a woven ballistic panel, the fabric can't respond everywhere at once — two coupled mechanical waves race outward from the impact point at two different, physically distinct speeds. This 2D cross-section fires a projectile at a taut aramid, UHMWPE, carbon or S-glass fiber panel and renders both waves separately: the fast longitudinal (extensional) stress wave at c_L = √(E/ρ), and the much slower transverse deformation cone at U = c_L√(v₀/2c_L), whose radius sets the "tent" shape spreading outward while the impact point sinks in. Live readouts track both wave speeds, the instantaneous fiber strain against the material's elongation-at-break, and the elastic energy absorbed by the engaged fiber network against the projectile's starting kinetic energy — whichever threshold is crossed first, at that exact frame, decides whether the panel arrests the round or is penetrated. Switch materials to see why a low-density, high-wave-speed fiber like Dyneema can outperform a stiffer but heavier one at the same impact velocity.