PROP_DAMAGE_CL
Material properties
"Optional title"
did, erode, noic
$W_c$, $G_I$, $\sigma_s$, $t_s$, $\alpha_s$, $\beta_s$
Parameter definition
Description
This is the Cockcroft-Latham failure criterion. It has been complemented with a tensile fracture/spalling criterion. Ductile damage is defined as:
$\displaystyle{D_d = \frac{1}{W_c} \int_0^{\varepsilon_{eff}^p} \mathrm{max}(0,\sigma_1) \mathrm{d}\varepsilon_{eff}^p}$
where $\sigma_1$ is the maximum principal stress. The complementing tensile damage is defined as:
$\displaystyle{ D_t = \frac{1}{t_s} \int_0^{t} (\bar{\sigma}_1 / \sigma_s )^{\alpha_s} \mathrm{d}t}$
$\bar{\sigma}_1$ is defined as:
$\bar{\sigma}_1 = \sigma_1^{dev} - (1-\beta_s) \cdot p$
where $\sigma_1^{dev}$ is the maximum deviatoric principal stress and $p$ is the pressure. With $\beta_s = 0$, $\bar{\sigma}_1$ equals the maximum principal stress. Note that the tensile fracture/spalling term only contributes to the damage growth if $\bar{\sigma}_1 \geq \sigma_s$. The material is assumed to fail when one of the damage parameters reaches 1.
Example
Defining damage parameter
The following input defines a damage parameter that depends on the distance from the material surface.
