Observations on the impact of a spherical projectile on particulate aggregations

Abstract

The dynamic behavior of particulate aggregation subjected to the impact of a steel spherical projectile was simultaneously recorded using two high-speed video cameras at different angles and analyzed numerically using a discrete element method. The effects of the impact velocity (1-25 m/s), impact angle (0-65 degrees), and size of the steel projectile on the dynamic response of particulate aggregation and projectile were examined. The movement of the projectile after impact can be classified into four types: penetration into particulate aggregation; stopping at the particulate aggregation surface; rebounding from particulate aggregation; and horizontal movement along the particulate aggregation surface. The type of movement depended on impact velocity and impact angle. The defining boundaries between the four types of movements became clearer as the size of the projectile increased. The results of numerical simulation also indicated that the magnitude, direction, and bifurcation of contact forces propagating into particulate aggregation play an important role in the change of the projectile's movement after impact.