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multiscale
lammps
Commits
6b9637ea
Commit
6b9637ea
authored
6 years ago
by
Trung Nguyen
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Added doc page for pair body rounded/polyhedron and updated related pages
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doc/src/body.txt
+34
-24
34 additions, 24 deletions
doc/src/body.txt
doc/src/pair_body_rounded_polygon.txt
+9
-5
9 additions, 5 deletions
doc/src/pair_body_rounded_polygon.txt
doc/src/pair_body_rounded_polyhedron.txt
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67 additions, 0 deletions
doc/src/pair_body_rounded_polyhedron.txt
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29 deletions
doc/src/body.txt
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6b9637ea
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@@ -240,34 +240,14 @@ The "pair_style body/rounded/polygon"_pair_body_rounded_polygon.html
command can be used with this body style to compute body/body
interactions.
For output purposes via the "compute
body/local"_compute_body_local.html and "dump local"_dump.html
commands, this body style produces one datum for each of the N
sub-particles in a body particle. The datum has 3 values:
1 = x position of vertex
2 = y position of vertex
3 = z position of vertex :pre
These values are the current position of the vertex within the
simulation domain, not a displacement from the center-of-mass (COM) of
the body particle itself. These values are calculated using the
current COM and orientation of the body particle.
:line
For images created by the "dump image"_dump_image.html command, if the
{body} keyword is set, then each body particle is drawn as a polygon
consisting of N line segments. Note that the line segments
are drawn between the N vertices, which does not correspond exactly to
the physical extent of the body (because the "pair_style
rounded/polygon"_pair_body_rounded_polygon.html defines finite-size
spheres at those point and the line segments between the spheres are
tangent to the spheres). The drawn diameter of each line segment is
determined by the {bflag1} parameter for the {body} keyword. The
{bflag2} argument is ignored.
[Specifics of body style rounded/polyhedron:]
The {rounded/polyhedon} body style represents body particles as
The {rounded/polyhed
r
on} body style represents body particles as
a polyhedron with N vertices, E edges and F faces.
Special cases for N = 1 (spheres) and N = 2 (rods) are also valid.
This body style is for 3d discrete element models, as described in "Wang"_#Wang.
Similar to body style {rounded/polygon}, the atom_style body command for this body
style takes two additional arguments:
...
...
@@ -313,6 +293,36 @@ For triangular faces, the last index should be set to -1.
:line
For output purposes via the "compute
body/local"_compute_body_local.html and "dump local"_dump.html
commands, this body style produces one datum for each of the N
sub-particles in a body particle. The datum has 3 values:
1 = x position of vertex
2 = y position of vertex
3 = z position of vertex :pre
These values are the current position of the vertex within the
simulation domain, not a displacement from the center-of-mass (COM) of
the body particle itself. These values are calculated using the
current COM and orientation of the body particle.
For images created by the "dump image"_dump_image.html command, if the
{body} keyword is set, then each body particle is drawn as a polygon
consisting of N line segments. Note that the line segments
are drawn between the N vertices, which does not correspond exactly to
the physical extent of the body (because the "pair_style
rounded/polygon"_pair_body_rounded_polygon.html defines finite-size
spheres at those point and the line segments between the spheres are
tangent to the spheres). The drawn diameter of each line segment is
determined by the {bflag1} parameter for the {body} keyword. The
{bflag2} argument is ignored.
:line
:link(Fraige)
[(Fraige)] F. Y. Fraige, P. A. Langston, A. J. Matchett, J. Dodds,
Particuology, 6, 455 (2008).
:link(Wang)
[(Wang)] J. Wang, H. S. Yu, P. A. Langston, F. Y. Fraige, Granular Matter, 13, 1 (2011).
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doc/src/pair_body_rounded_polygon.txt
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6b9637ea
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@@ -11,15 +11,16 @@ pair_style body/rounded/polygon command :h3
[Syntax:]
pair_style body/rounded/polygon c_n c_t mu delta_ua cutoff :pre
c_n = normal damping coefficient
c_t = tangential damping coefficient
mu = normal friction coefficient during gross sliding
delta_ua = multiple contact scaling factor
cutoff = global sepration cutoff for interactions (distance units), see below for definition
cutoff = global sepration cutoff for interactions (distance units), see below for definition
:pre
[Examples:]
pair_style body/rounded/polygon
${c_n} ${c_t} ${mu} ${delta_ua} ${cutoff}
pair_style body/rounded/polygon
20.0 5.0 0.0 1.0 0.5
pair_coeff * * 100.0 1.0
pair_coeff 1 1 100.0 1.0 :pre
...
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@@ -36,12 +37,13 @@ which is specified as an argument to the "atom-style body" command.
See the "body/rounded/polygon"_body.html doc page for more details about the body
styles LAMMPS supports. The pairwise interaction between the rounded polygons is described
in "Fraige"_#Fraige, where the polygons are rounded at the vertices and edges
by circles of diameter a.
by circles of diameter a. This is a version of discrete element models (DEM)
with multiple contact points.
Because the polygons can have different rounded diameters, the cutoff specified in
the pair style command is for the surface separation between two interacting entities
(e.g. vertex-vertex, vertex-edge or edge-edge) excluding their rounded diameters,
i.e. separation = center-center distance - (rounded diameter of i + rounded diameter of j)/2.
i.e. separation = center-center distance - (rounded diameter of
entity
i + rounded diameter of
entity
j)/2.
The interaction forces and energies are also defined with respect to the rounded surface separation,
instead of center-center distance.
...
...
@@ -56,10 +58,12 @@ k_na (energy/distance^2) :ul
[Related commands:]
"pair_
style body
"_pair_
body
.html
"pair_
coeff
"_pair_
coeff
.html
[Default:] none
:link(Fraige)
[(Fraige)] F. Y. Fraige, P. A. Langston, A. J. Matchett, J. Dodds,
Particuology, 6, 455 (2008).
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doc/src/pair_body_rounded_polyhedron.txt
0 → 100644
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6b9637ea
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)
:line
pair_style body/rounded/polyhedron command :h3
[Syntax:]
pair_style body/rounded/polyhedron c_n c_t mu delta_ua cutoff :pre
c_n = normal damping coefficient
c_t = tangential damping coefficient
mu = normal friction coefficient during gross sliding
delta_ua = multiple contact scaling factor
cutoff = global sepration cutoff for interactions (distance units), see below for definition :pre
[Examples:]
pair_style body/rounded/polyhedron 20.0 5.0 0.0 1.0 0.5
pair_coeff * * 100.0 1.0
pair_coeff 1 1 100.0 1.0 :pre
[Description:]
Style {body/rounded/polyhedron} is for use with body particles and calculates pairwise
body/body interactions as well as interactions between body and
point-particles. See "Section 6.14"_Section_howto.html#howto_14
of the manual and the "body"_body.html doc page for more details on
using body particles.
This pair style is designed for use with the "body/rounded/polyhedron" body style,
which is specified as an argument to the "atom-style body" command.
See the "body/rounded/polyhedron"_body.html doc page for more details about the body
styles LAMMPS supports. The pairwise interaction between the rounded polygons is described
in "Wang"_#Wang, where the polygons are rounded at the vertices and edges
by circles of diameter a. This is a version of discrete element models (DEM)
with multiple contact points.
Because the polygons can have different rounded diameters, the cutoff specified in
the pair style command is for the surface separation between two interacting entities
(e.g. vertex-vertex, vertex-edge, vertex-face and edge-edge) excluding their rounded diameters,
i.e. separation = center-center distance - (rounded diameter of entity i + rounded diameter of entity j)/2.
The interaction forces and energies are also defined with respect to the rounded surface separation,
instead of center-center distance.
For style {body/rounded/polyhedron}, the following coefficients must be defined for each
pair of atoms types via the "pair_coeff"_pair_coeff.html command as in
the examples above, or in the data file or restart files read by the
"read_data"_read_data.html or "read_restart"_read_restart.html
commands:
k_n (energy/distance^2)
k_na (energy/distance^2) :ul
[Related commands:]
"pair_coeff"_pair_coeff.html
[Default:] none
:link(Wang)
[(Wang)] J. Wang, H. S. Yu, P. A. Langston, F. Y. Fraige, Granular Matter, 13, 1 (2011).
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