"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)

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pair_style smd/ulsph command :h3

[Syntax:]

pair_style smd/ulsph args :pre

these keywords must be given :ul
keyword = {*DENSITY_SUMMATION} or {*DENSITY_CONTINUITY} and {*VELOCITY_GRADIENT} or {*NO_VELOCITY_GRADIENT} and {*GRADIENT_CORRECTION} or {*NO_GRADIENT_CORRECTION} :pre

[Examples:]

pair_style smd/ulsph *DENSITY_CONTINUITY *VELOCITY_GRADIENT *NO_GRADIENT_CORRECTION :pre

[Description:]

The {smd/ulsph} style computes particle interactions according to
continuum mechanics constitutive laws and an updated Lagrangian
Smooth-Particle Hydrodynamics algorithm.

This pair style is invoked similar to the following command:

pair_style smd/ulsph *DENSITY_CONTINUITY *VELOCITY_GRADIENT *NO_GRADIENT_CORRECTION
pair_coeff i j *COMMON rho0 c0 Q1 Cp hg &
               *END :pre

Here, {i} and {j} denote the {LAMMPS} particle types for which this
pair style is defined. Note that {i} and {j} can be different, i.e.,
{ulsph} cross interactions between different particle types are
allowed. However, {i}--{i} respectively {j}--{j} pair_coeff lines have
to precede a cross interaction.  In contrast to the usual {LAMMPS}
{pair coeff} definitions, which are given solely a number of floats
and integers, the {ulsph} {pair coeff} definition is organized using
keywords. These keywords mark the beginning of different sets of
parameters for particle properties, material constitutive models, and
damage models. The {pair coeff} line must be terminated with the
{*END} keyword. The use the line continuation operator {&} is
recommended. A typical invocation of the {ulsph} for a solid body
would consist of an equation of state for computing the pressure (the
diagonal components of the stress tensor), and a material model to
compute shear stresses (the off-diagonal components of the stress
tensor).

Note that the use of *GRADIENT_CORRECTION can lead to severe numerical
instabilities. For a general fluid simulation, *NO_GRADIENT_CORRECTION
is recommended.

Please see the "SMD user guide"_PDF/SMD_LAMMPS_userguide.pdf for a
complete listing of the possible keywords and material models.

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[Mixing, shift, table, tail correction, restart, rRESPA info]:

No mixing is performed automatically.  Currently, no part of USER-SMD
supports restarting nor minimization.  rRESPA does not apply to this
pair style.

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[Restrictions:]

This fix is part of the USER-SMD package.  It is only enabled if
LAMMPS was built with that package.  See the "Build
package"_Build_package.html doc page for more info.

[Related commands:]

"pair_coeff"_pair_coeff.html

[Default:] none

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