Equation of state formulation for unreacted solid high explosives, PETN and HMX

Equation of state (EOS) for unreacted explosives has been formulated thermodynamically aiming at using with numerical code of SDT processes. A generalized form of EOS is given in terms of p-v-E from the available static isothermal compression curve with non-constant specific heat, and arbitrary Gr\"{u}neisen volume function. In this paper, a procedure of providing p-v-E EOS is developed based on the specific heat at constant volume as a function of entropy, Gr\"{u}neisen volume function, together with Birch-Murnagan form of the isotherm. Material function of EOS and shock Hugoniot for PETN and HMX has been calculated, which is compared with the experimental data of shock-particle velocity Hugoniot. Dependence of shock pressure and temperature on the Gr\"{u}neisen volume function is discussed. Insensitivity of the shock-particle velocity relationship to functional form of Gr\"{u}neisen volume function is also shown.