PARTICLE_SOIL

Particle
*PARTICLE_SOIL
"Optional title"
sid
type, gid, $dsf$, ., ., ., ., $t_{end}$
$\rho_0$, $k$, $\mu$, $\xi$, $v$, $\eta$
Parameter definition
VariableDescription
sid Subdomain ID
type Soil type
options:
DRY $\rightarrow$ dry sand
WET $\rightarrow$ fully saturated wet sand
USER $\rightarrow$ user defined
gid Geometry ID
$dsf$ Particle density scale factor (particles per unit volume)
default: 1
$t_{end}$ Particle deactivation time or FUNCTION (fcn)
options: time or fcn
default: not used
$\rho_0$ Density (this line is only used if type=USER)
$k$ Grain contact stiffness
$\mu$ Grain contact coefficient of friction
$\xi$ Grain contact damping coefficient
$v$ Fill fraction (typically between 0.58 and 0.62)
$\eta$ Dimensionless shear cap coefficient
Description

Discrete particle soil domain definition.

The subdomain ID (sid) determines in which order particles are filled into the global domain. In case subdomains are overlapping, the domain with the largest ID will overwrite (remove) particles belonging to domains with lower domain ID's.

The presets of sand are defined as follows (in SI-units):

$\begin{array}{cccc} \mbox{Variable} & \mbox{Unit} & \mbox{Dry} & \mbox{Wet} \\ \rho_0 & [kg/m^3] & 1620 & 2020 \\ k & [N/m] & 5.0e8 & 4.0e9 \\ \mu & [-] & 0.5 & 0.0 \\ \xi & [kg/s] & 0.0 & 0.005 \\ v & [-] & 0.6 & 0.625 \\ \eta & [-] & 0.0 & 0.0 \end{array}$
Example
Generic mine in sand

Simple example of a generic TNT mine positioned in dry sand against a steel plate.


*UNIT_SYSTEM
SI
*PARAMETER
L = 2, "Plate size"
h = 0.02, "Plate thickness"
soff = 0.3, "Stand-off distance"
Np = 1000000, "Number of particles"
tend = 0.02, "Simulation time"
A = 340.0e6
B = 500.0e6
n = 0.3
*TIME
[%tend]
#
# --- MESH ---
#
*COMPONENT_BOX
"Target plate"
1, 1, 20, 20, 1
[-%L/2], [-%L/2], [%soff], [%L/2], [%L/2], [%soff+%h]
*CHANGE_P-ORDER
P, 1, 3
#
# --- MATERIAL ---
#
*MAT_METAL
1, 7800.0, 210.0e9, 0.3, 1
1
*FUNCTION
1
%A + %B*epsp^%n
*PROP_DAMAGE_CL
1, 3
100.0e6
*PART
"Target plate"
1, 1
#
# --- PARTICLES ---
#
*PARTICLE_DOMAIN
ALL, 0, [%Np]
[-%L/2], [-%L/2], -1, [%L/2], [%L/2], 1
1, 1, 1, 1, 1, 0
*PARTICLE_SOIL
1
DRY, 123
*PARTICLE_HE
2
TNT, 44
*PARTICLE_DETONATION
1
0, 0, -0.14, 0
#
# --- GEOMETRIES ---
#
*GEOMETRY_BOX
"Dry Sand"
123
[-%L/2], [-%L/2], -1, [%L/2], [%L/2], 0
*GEOMETRY_PIPE
"Generic mine"
44
0, 0, -0.18, 0, 0, -0.1, 0.125
*END