MAT_UNDETONATED_EXPLOSIVE

Material properties
*MAT_UNDETONATED_EXPLOSIVE
"Optional title"
mid, $\rho$, $E$, $\nu$, ., ., eosid
$A$, $B$, $n$, $c$, $\dot{\varepsilon}_0$, $p_{det}$, $t_{det}$, $\alpha_{det}$
Parameter definition
VariableDescription
mid Unique material identification number
$\rho$ Density
$E$ Young's modulus
$\nu$ Poisson's ratio
eosid Equation-of-state ID
$A$ Initial yield strength
$B$ Hardening parameter
$n$ Hardening exponent
$c$ Strain rate hardening parameter
$\dot{\varepsilon}_0$ Reference strain rate
default: $1 s^{-1}$
$p_{det}$ Threshold detonation pressure
$t_{det}$ Detonation activiation time
$\alpha_{det}$ Pressure sensitivity exponent
Description

This is an elasto-plastic material model that is used to predict the detonation onset in explosive materials.

$\displaystyle{\sigma_y = \left( A + B(\varepsilon_{eff}^p)^n \right) \cdot \left( 1 + \frac{\dot{\varepsilon}_{eff}^p}{\dot{\varepsilon}_0} \right)^c}$

Detonation will occur when a damage variable $D$ (starting at $0$) reaches the value $1$.

$\displaystyle{ \dot{D} = \left[ \left( \frac{\mathrm{max}(0,p)}{p_{det}} \right)^{\alpha_{det}} - 1 \right] \cdot \frac{1}{t_{det}} }$

Note that $D$ shrinks at pressures below $p_{det}$, but it is not allowed to drop below $0$.