Dynamics of oblique impact in a photoelastic granular medium

Abstract

When a solid projectile impacts a granular target, it experiences a drag force and abruptly comes to rest as its momentum transfers to the grains. An empirical drag force law successfully describes the force experienced by the projectile, and the corresponding grain-scale mechanisms have been deciphered for normal impacts. However, there is little work exploring non-normal impacts. Accordingly, we extend studies to explore oblique impact, in which a significant horizontal component of the drag force is present. In our experiments, a projectile impacts a quasi-two-dimensional bed of bidisperse photoelastic grains. We use high-speed imaging to measure high-resolution position data of the projectile trajectory and simultaneously visualize particle-scale force propagation in the granular medium. When the impact angle becomes important, the spatial structure of the stress response reveals relatively weak force chain propagation in the horizontal direction. Based on these observations, we describe the decrease of the inertial drag force with impact angle.

arXiv comment7 pages, 6 figures

References in corpus (8)

• A Terradynamics of Legged Locomotion on Granular Media
• Unified force law for granular impact cratering
• Scaling and dynamics of sphere and disk impact into granular media
• Particle Scale Dynamics in Granular Impact
• Influence of confinement on granular penetration by impact
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Cited by in corpus (3)

• Ricochets on Asteroids: Experimental study of low velocity grazing impacts into granular media
• Subsurface pulse, crater and ejecta asymmetry from oblique impacts into granular media
• Ricochets on Asteroids II: Sensitivity of laboratory experiments of low velocity grazing impacts on substrate grain size