Dynamic simulations of projectile penetration into granular medium

Abstract

Dynamic FEM and DEM simulations are carried out to investigate dynamic penetration of a projectile into a target of granular medium. Spatial distribution and time dependence of ejecta are clarified together with their trajectories in medium. Highly densified region is generated just ahead of the projectile and propagates leaving rarefied regions. Force on the projectile is fully discussed in connection with dynamic behavior of granular target.

Simulation of dynamic response of projectile and granular target

“…9. Significant increase of peak value can be understood by change of momentum of particles in target as discussed before [6].…”

“…5. Now, we can see the effect of mechanical properties of projectile upon the resistance force as shown in With taking account of dependence of the wave velocity C t in the target on the impact velocity as was mentioned before [6], evaluated values of ρ t C t A t at impact velocity of 120 m/s and at 240 m/s are still slightly different, but this can be understood by considering a possible change of A t by impact velocity already reported [6]. After the initial reaction, the stress wave in the projectile goes up and down and re-impact is continued to the target.…”

“…The effective sectional area of target, A, can be estimated as before [6], and is almost constant independent of the impact velocity. On the other hand, elastic wave velocity of the target depends on the impact velocity as shown in Fig.…”