An equation of state for abnormal expansion of shocked porous materials

Abstract

Abnormal expansion phenomena occur in various types of shocked porous materials with relatively high porosity. In this work, we propose a way to treat the shock velocity D and particle velocity u data of shocked porous materials and then deduce a new equation of state (EOS). Validations show that this new EOS can well describe the pressure-volume data of porous materials over a wide range of porosity and pressure. In particular, the abnormal expansion is satisfactorily reproduced. Furthermore, based on the new EOS, a unified functional form of the EOS is deduced to describe the shock, isentropic, and isothermal compression of solid materials, which facilitates the mutual calculation among different kinds of compression states.