Thermodynamic Effects of Shock Compression and the Hugoniot Curve

Thermodynamic Effects of Shock Compression and the Hugoniot Curve 

In an ideal fluid, the stresses are isotropic. There is no strength, so there are no shear stresses the normal stress and lateral stresses are equal and are identical to the pressure. On the other hand, a solid with strength can support shear stresses. However, when the applied stress greatly exceeds the yield stress of a solid, its behavior can be approximated by that of a fluid because the fractional deviations from stress isotropy are small. Under these conditions, the solid is considered to be hydrodynamic. In the absence of rate-dependent behavior such as viscous relaxation or heat conduction, the equation of state of an isotropic fluid or hydrodynamic solid can be expressed in terms of specific internal energy as a function of pressure and specific volume E(P, V). A familiar equation of state is that for an ideal gas 

A commonly used equation of state for solids is the Mie-Griineisen equation 

The Rankine-Hugoniot curve is sometimes referred to as the shock adiabat (especially in the Soviet literature). This terminology reflects the fact that the shock process is so fast that there is insufficient time for heat 

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