Command manual

Command list

PARTICLE_SPH

Particle
*PARTICLE_SPH
"Optional title"
coid
mid, gid, correction, $s$, $dsf$, ., ., $t_{end}$

Parameter definition

VariableDescription
coid Sub-domain ID
mid Material ID
gid Geometry ID
correction Dynamic SPH node coordinate correction
options:
0 $\rightarrow$ weak correction
1 $\rightarrow$ strong correction
2 $\rightarrow$ no correction
$s$ Smoothing length scale factor
default: 2.5
$dsf$ 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

Description

SPH material domain definition.

The command id (coid) determines in which order particles are filled into the global domain. In case sub-domains are overlapping, the domain with the largest ID will overwrite (remove) particles belonging to domains with lower domain ID's.

The smoothing length (radius) is defined as:

$\displaystyle{ R = s \cdot h }$

where $h$ is the initial SPH node spacing and the default value of $s=2.5$.

There is, by default, a dynamic repositioning of SPH coordinates that helps supressing tensile instability modes. This feature can be turned off by setting correction$=2$.

The SPH particle density scale factor $dsf$ is optional and it is used to control the relative particle density (number of particles per unit volume) in the different sub-domains. Increasing $dsf$ for a sub-domain means that a larger fraction of the total number of particles will be allocated to that specific sub-domain.