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PARTICLE_SPH

Particle

*PARTICLE_SPH
"Optional title"
sid
mid, gid, correction, $s$, $dsf$, -, slide, $t_{end}$
csysid

Parameter definition

Variable
Description
sid
Subdomain 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
-
Reserved
slide
Sliding contact flag
options:
0 $\rightarrow$ full merge
1 $\rightarrow$ sliding only
$t_{end}$
Particle deactivation time or FUNCTION (fcn)
options: time or fcn
default: not used
csysid
ID of optional coordinate system defining SPH node distribution directions

Description

SPH subdomain 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.

Currently supported material models are MAT_FLUID, MAT_GRANULAR_CAP, MAT_HJC_CONCRETE, MAT_JH_CERAMIC, MAT_METAL, MAT_MMC_OST, MAT_ZA.

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 subdomains. Increasing $dsf$ for a subdomain means that a larger fraction of the total number of particles will be allocated to that specific subdomain.

By default, SPH particles using different material ID's will merge when coming into contact. However, this interaction can be changed to friction free sliding by setting slide=1.