Penetration of a projectile by impact into a granular medium

Abstract

When a solid sphere drops in a granular medium, an impact crater is created. The penetration of the projectile in the granular bed as a function of the impact energy is evaluated theoretically using a simple model including a friction law between the projectile and the grains, a viscous dissipation in the bed and a force from the collisions between the projectile and the granular material. This model is observed to be in agreement with our quasi-2D experimental results and suggests that the penetration depth is a power law of the total drop distance. © 2009 Springer-Verlag Berlin Heidelberg.