“…The Mie–Gruneisen equation of state was adopted for copper, 1060 aluminium and Q235 steel, and the formula for the material when it was stretched was [22,23]
where P is initial the pressure, P H is the current pressure, Γ 0 is the Grüneisen coefficient, ρ H is the current density, ρ 0 is the initial density of the material, c 0 is the volume sonic velocity, s is the material constant, e H is the current pressure, and e is the initial inner energy.…”