High velocity impact characterization of Al alloys for oblique impacts

• The finding out of the relationship between oblique impact and damage areas.
• Found an increasing trend in energy absorption with the increase of obliquity.
• Inner wall damage area was found 6%, 26% and 53% greater w.r.t projectile area.
• Such damage areas are for oblique impacts of 30°, 45°, and 60°, for 1000±200 m/s.
• The LSDYNA simulation and validation suggested to be used for hypervelocity impacts.

This paper describes the experimental and computational analyses of a high velocity aluminum projectile impact on an Al6061-T6 spacecraft inner wall at different oblique angles. Al2017-T4 spherical projectiles of 5.56 mm in diameter and 0.25 g in weight were chosen within the velocity range of 1000±200 m/s due to the limitation of the light gas gun. The energy absorbed was calculated by measuring the velocities before and after impact on the inner wall. The energy absorbed by the wall and the remaining energy carried by the projectile helped to estimate the severity of further damage to inner components. Afterwards, validation was done by using the commercially available software LS-DYNA with a dedicated SPH. On average, a 10% energy absorption difference between experimentation and simulation was found. By using C-SCAN, the damage area proportion of the total inner wall to impact penetration hole area was found to be on average 6%, 26% and 53% greater than the projectile cross sectional area for the oblique angle impacts of 30°, 45°, and 60°, respectively. These findings helped to understand the relationship between the oblique impact event and the damage area on a spacecraft inner wall along with space debris cloud propagation and comparison with experimental results using LS-DYNA.