Shock Propagation in the Three-Dimensional Lattice. I. Model and Results

Shock propagation in a three-dimensional, monatomic, face-centered-cubic (FCC) lattice is studied using a computer-molecular-dynamic (CMD) technique. It is demonstrated that compression of the lattice gives rise to a spectrum of well-defined, longitudinal pulses (solitary waves) which propagate in the vicinity of the shock front amid the thermal background of the lattice. The properties of these pulses are examined in some detail and it is demonstrated that they are not completely stable. Rather, they tend to decay as they propagate into the lattice, producing both random, thermal motion and, in some cases, transverse solitary-wave motion. The effects of the solitary waves upon the temperature, density, and stress profiles and upon the approach to thermal equilibrium behind the shock front are investigated. See also Rept. no. ARBRL-TR-02175, AD-A074 263.