Energy Absorption Capacity of carbon nanotubes under ballistic impact

Carbon nanotubes have great potential applications in making ballistic-resistance materials. This letter analyzes the impact of a bullet on nanotubes of different radii in two extreme cases. For a nanotube with one end fixed, the maximum nanotube enduring bullet speed increases and the energy absorption efficiency decreases with the increase in relative heights at which the bullet strikes; these values are independent of the nanotube radii when the bullet hits at a particular relative height. For a nanotube with both ends fixed, the energy absorption efficiency reaches minimum when the bullet strikes around a relative height of 0.5.