Micromechanics of shock deformation of granular materials

A two-dimensional, multi-material, Eulerian finite element program was used to investigate the micromechanical behavior of a granular material (nickel-based alloy) with different particle sizes and initial porosities under impulsive loading and compared with the experiments. It was shown that: 1) increasing the shock pressure results in a transition from quasistatic to dynamic deformation regimes, 2) the transition pressure depends on porosity and does not depend on particle size, and 3) the well-developed dynamic regime correlates with the microkinetic energy. In the calculations, the internal energy behind the shock agrees with the stationary conditions, and the shock front thickness is close to the particle size at the investigated pressures.