"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)

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pair_style smd/ulsph command :h3

[Syntax:]

pair_style smd/ulsph args :pre

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

[Examples:]

pair_style smd/ulsph *DENSITY_CONTINUITY *VELOCITY_GRADIENT *NO_GRADIENT_CORRECTION

[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 organised 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 "Making LAMMPS"_Section_start.html#start_3
section for more info.

[Related commands:]

"pair_coeff"_pair_coeff.html

[Default:] none

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