An Experimental Study to Investigate Hypervelocity Impacts on Pressure Vessels

Thin-walled cylindrical gas-filled pressure vessels made of aluminium alloy and unalloyed titanium were impacted by hypervelocity aluminium projectiles. Impact velocity was fixed at 7 km/s, projectile sizes ranged up to 4.9 mm for the Al-vessels, and up to 10mm for the Ti-vessels. The pressure was varied up to roughly 95 per cent of the experimental static burst pressure. The loading conditions that lead to catastrophic rupture were established. It was found that at high hoop stresses the amount of kinetic energy needed to rupture the vessel is low whereas at low wall stresses large impact energies are required to cause catastrophic rupture. In some experiments crack propagation started in the impact hole, which is a failure mode for gas-filled pressure vessels that has not been reported before. A few experiments involved shielded vessels. It weas demonstrated that shielding may prevent catastrophic rupture.