DEM/FEM simulation for impact response of binary granular target and projectile

Abstract

Three-dimensional dynamic discrete element method (DEM) and finite element method (FEM) simulation using LS-DYNA were, respectively, applied to the randomly distributed binary granular material and to the cylindrical projectiles in order to clarify the effect of size distribution of target particles on the dynamic behaviour of low density granular material. It was found that the peak resistance force of projectile during penetration depends on the packing density of the granular materials and on the impact velocity of projectile. The change of resistance force was well understood in connection with the propagation and the reflection of stress wave in projectile. The variety of particle size almost did not affect the resistance force of projectile. Densified region in granular material was generated ahead of projectile after impact. The densified region propagated in the depth direction and its propagation speed depended on the packing density of target granular material and impact velocity of projectile. That is, projectile impact behaviours of granular materials can be uniformly handled by impact velocity and packing density of the granular material, not depending on the variety of the particle size.