Study on damage of a reinforced aircraft skin subjected to 12.7 mm projectile impact

To investigate the damage evolution of a reinforced aircraft skin impacted by a projectile with diameter 12.7 mm, LY-12 plate with thickness 3 mm and reinforced aircraft skin are shoot by the projectile. An effective testing system of simulating battle damage is experimentally developed, which consists of high pressed airgun, an assembled projectile body and bullet-shoe design, an instantaneous velocity measurement system with laser and lens, set-up frame for the specimens, and the projectile trap box. First, LY-12 CZ plates with thickness 3 mm are fixed around, and shoot by the projectile under the velocities from 60 m/s to 300 m/s. The results show that effective diameter of the deformation region by projectile impact decreases with increasing the velocity of the bullet, it follows a power law. The dynamic strain on the pate linearly decreases with increasing projectile velocity. The residual velocity of the bullet linearly rises with the velocities. Then, reinforced aircraft skins are tested by the same process as LY-12 CZ plates, the numerical simulations are performed. Comparison of the test results and numerical simulation show that the developed simulation technique is effective to simulate battle damage of the aircraft.