Command manual

Command list

EOS_GRUNEISEN

Material properties
*EOS_GRUNEISEN
eosid, $S$, $\Gamma$, $L$, $p_{cut}$

Parameter definition

VariableDescription
eosid Unique EOS identification number
$S$ Linear Hugoniot slope coefficient
$\Gamma$ Gruneisen gamma
$L$ Characteristic element size in shock viscosity calculation
default: automatically calculated
$p_{cut}$ Pressure cut-off ($\gamma SPH$ only)

Description

This is the Mie-Gruneisen equation-of-state. Note that the linear bulk modulus, $K$, is determined from the elastic properties in the material command.

$p = \displaystyle{ \frac{K \eta}{(1-S \eta)^2} \cdot \left( 1 - \frac{\Gamma \eta}{2} \right) + \Gamma \rho_0 e }$

where $\rho$ is the current density, $\rho_0$ is the initial density and $e$ is the specific internal energy. $\eta$ is a measure of the volumetric compression.

$\displaystyle{ \eta = 1 - \frac{\rho_0}{\rho}}$