Modelling the Shock Response of Polycrystals at the Mesoscale

摘要

Simulation of the shock compression of a copper polycrystal at the mesoscale has been carried out using a Discrete Element code. Grains were aligned in three crystal orientations with respect to the shock direction; 100, 110, and 111. The polycrystal had an average grain diameter of 14μm and was impacted by a single crystal of copper at 200m/s. Results show the presence of a Particle Velocity Dispersion which attains its maximum magnitude of 8m/s at the plastic wave rise, and which is quantitatively of the same order as experimentally observed values. Non-planar elastic and plastic wave fronts are present. The shock front position distribution increases with propagation distance until its standard deviation is 0.4μm at a propagation distance of 80μm.