On the influence of pressure and porosity on the parameters of the equation of state of a porous substance

The influence of porosity and pressure on the parameters of the equation of state of a porous material is studied. The model takes into account the presence of gas in the pores. The equations of state of the mixture and its components, both solid and gaseous, are presented uniformly (in the form of the Mie–Grüneisen equation with the Grüneisen coefficient depending on density). To describe the Grüneisen coefficient, a logarithmic dependence on density is used. Numerical calculations of shock-wave loading and isentropic unloading of copper samples of various porosities are carried out. It is shown that the parameters of the equation of state obtained under normal conditions adequately describe the behavior of the substance both under loading and unloading.