Studies on the Equilibrium State of Mixture Following Shock Compression

The mixture is as a randomly distributed component grains in three-dimensional meshes. The shock compression behavior of mixtures is simulated numerically by using the 3D thermodynamics finite element method. We have studied the course of tendency to the thermodynamic equilibrium, the characteristic time of temperature equilibrium, the characteristic time of pressure equilibrium and the equilibrium state of mixture following the shock compression and found the relation between the characteristic time of temperature equilibrium and the square of the grain dimension of mixture and the linear relation between the characteristic time of pressure equilibrium and the grain dimension. The shock compression behaviors of some alloys are simulated numerically, and the results are compared with the fraction volume model of EOS, the superposition principle of the first shock Hugoniot, and the experimental results. Except for the shock temperature, the results are in good agreement with each other. The fraction volume model and the superposition principle cannot yield reasonable shock temperatures, but the numerical simulation method does.