Investigation on damage characteristics of thin Al-plates by oblique hypervelocity impact of Al-sphere

The oblique hypervelocity impacts of space debris on bumper of spacecrafts were studied through 2017 aluminum spheres impacting on thin 2A12 aluminum alloy sheets at different angles. The penetration hole characteristics of single-wall shields and the ricochet characteristics of projectiles were analyzed. The equations for the hole size of oblique hypervelocity impact penetration into thin aluminum alloy sheets were derived. Impact velocities were 2.58 km/s, 3.56 km/s and 4.31 km/s respectively. Impact angles ranged from 0° to 80°. The results indicated that the penetration hole size in thin aluminum alloy sheets depended on the impact velocity and impact angle. When an aluminum alloy sphere of 3.97 mm diameter impacted at hypervelocity on the thin aluminum alloy sheet of 1 mm thickness at different angles, the critical impact angle was between 30° and 40° in which projectile leaped away from the target partially. As impact angle increased, the maximum ricochet angle decreased, and the distributing area of ricochet debris cloud reduced. Impact velocity has little effect on the penetration hole ellipticity of thin aluminum alloy sheets under oblique hypervelocity impact.