ALUMINUM SHIELD UNDER HYPERVELOCITY IMPACT OF MYLAR FLYER

摘要

The near-earth space environment is cluttered with man-made debris and naturally occurring meteoroids, which is a big menace to the safety of satellites and spacecrafts. This paper is addressed on the failure response of aluminum shields under hypervelocity impact of milligrame level flyer. A compacted electric gun is employed to accelerate a mylar flyer up to 10 km/s. Failure response of Lyl2 aluminum shields with different thickness and layers impacted by mylar flyer with different velocities is under investigation. The spallation is observed in the rear free surface of 4 mm thick monolithic aluminum shield, and its fracture mechanism changes from plastic to brittle when loading pressure is above 13 GPa. A perforation with a diameter 8 mm in the impacted area of the 4mm thick Ly12 shield is observed after which is impacted by 0.1 mm thick mylar flyer 8mm in diameter with velocity 8.2 km/s. When three layers of shields are impacted, the debris clouds(DC) are observed in the first and the second spaces respectively during the impact process by high speed camera, and its leftover can be observed on the surface of the third plate. The shape of the first debris cloud head is a little flat, and its speed of lateral expansion is very slow, which is different from those impacted by spherical projectile, and its formation mechanics mainly attributes to multi-spallations based on the analysis of simulation.