Analysis of the fracture of gas-filled pressure vessels under hypervelocity impact

The first part of the study summarizes the results of hypervelocity impact tests on unshielded thin-walled cylindrical pressure vessels made of alumin ium alloy. Impact damages ranged from simple front wall perforation with no further damages inside the vessel to catastrophic bursting into many piece s. Two types of catastrophic bursting were observed: front side and rear si de failure. Front side failure was initiated at the rim of the front side i mpact hole. The second part of the study analyzes the physical mechanisms t hat are involved in the hypervelocity impact process on pressure vessels an d simulates the experimental results presented in the first part. In order to treat this problem, the fragment cloud that was generated from the front side impact was assumed to be completely ablated and decelerated in the ga s, which is in correspondance with experimental observations for pressures exceeding a few atmospheres. In the presented model the impact event was di vided in different stages, that are treated separately. These are: perforat ion of the front wall and generation of a strong gas shock wave, propagatio n and damping of the gas shock wave, impact of the gas shock wave on the re ar wall and reflection thereof, propagation of the gas shock wave to the fr ont side and interaction with it. Models for the treatment of front and rea r side failure mechanisms are presented. The validity of the presented anal ysis was proven by simulation of the experimental results obtained in the f irst part of the paper. (C) 1999 Elsevier Science Ltd. All rights reserved.