Modeling of impact cratering in granular media

We simulate penetration of large projectiles into dry granular media using two-dimensional soft particle molecular dynamics. We systematically vary the physical parameters of the projectile (density, size, impact energy). Our results confirm the recently observed scaling of the crater depth with impact energy as observed by Uehara et al. (2003) and the effect of constant deceleration of the ball during the penetration phase as observed by Ciamarra et al (2004). We calculate the distribution of energy dissipation during the impact among different dissipation mechanisms and conclude that most dissipation occurs due to internal frictional contacts among the grains. We also propose a model which describes the observed scaling regimes of impact cratering.