Response of granular media to rapid penetration

• Fundamental physics of projectile penetration into sand are reviewed.
• Effects of projectile and soil properties on penetration is examined.
• Methods to predict the response of soils to projectile impact are summarized.
• Impact-cratering briefly presented.
• Laboratory-scale effects are outlined to aid with data interpretation.

There has been a flurry of interest over the past decade in the study of impact and penetration into granular media. A wealth of knowledge has resulted from these efforts. This review summarizes some of the significant findings of these recent studies, and attempts to bridge the resulting insights with those obtained from earlier findings. The effects of projectile properties as well as soil behavior on penetration are examined at the meso- and macro-scales, and significant insights into the fundamental physics of projectile penetration in sand are outlined. Issues relating to laboratory-scale physical modeling are presented to aid with interpretation of experimental data. Empirical and analytical methods to predict the response of soils to projectile impact are also summarized. Finally, a brief description of the impact-cratering and other transients of penetration is presented for completeness.