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PARTICLE_SOIL

Particle

*PARTICLE_SOIL
"Optional title"
sid
type, gid, $dsf$, -, -, -, -, $t_{end}$
$\rho_0$, $k$, $\mu$, $\xi$, $v$, $\eta$

Parameter definition

Variable
Description
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
-
Reserved
-
Reserved
-
Reserved
-
Reserved
$t_{end}$
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