Modeling of projectile penetration using transparent soils

Low velocity projectile penetration in soils has several important military and civilian applications. Complex soilprojectile interactions occur during penetration. Numerical models are often employed to capture these interactions. However, there is little information in the literature with respect to soil-projectile kinematic interactions. In this paper, the results of low velocity projectile penetration in granular media are presented. Refractive index matched transparent soil with mechanical properties similar to angular natural sand is used as the target granular media. High-speed imaging is adapted to capture images of an embedded axisymmetric plane within the sample during projectile penetration. Digital image correlation is used to derive the temporal evolution of the displacement field during penetration. Kinematic analysis is performed to investigate the characteristics of the soil-projectile interactions. The results indicate that the soil immediately below the projectile moves predominantly downward as the projectile approaches the soil. Radially away from the projectile, there is a transition from downward movement to horizontal movement. Once the projectile passes a given depth, the soil continues to move downward, as momentum is transferred to the soil.