lammps/doc/pair_peri_pmb.html

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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
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<HR>
<H3>pair_style peri/pmb command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>pair_style peri/pmb
</PRE>
<P><B>Examples:</B>
</P>
<PRE>pair_style peri/pmb
pair_coeff * * 1.6863e22 0.0015001 0.0005 0.25
</PRE>
<P><B>Description:</B>
</P>
<P>Style <I>peri/pmb</I> style implements the Peridynamic bond-based prototype
microelastic brittle (PMB) model, which can be used to model materials
at the mesoscopic or macroscopic scale. The canonical paper on
Peridynamics is <A HREF = "#Silling">(Silling)</A>. The implementation of
Peridynamics in LAMMPS is described in <A HREF = "#Parks">(Parks)</A>. Also see the
<A HREF = "http://www.sandia.gov/~mlparks/papers/PDLAMMPS.pdf">PDLAMMPS user
guide</A> for more
details about this particular potential and using it in LAMMPS.
</P>
<P>The following coefficients must be defined for each pair of atom
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
above, or in the data file or restart files read by the
<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
commands, or by mixing as described below:
</P>
<UL><LI>c (energy/distance/volume^2 units)
<LI>horizon (distance units)
<LI>s00 (unitless)
<LI>alpha (unitless)
</UL>
<P>C is the effectively a spring constant for Peridynamic bonds, the
horizon is a cutoff distance for truncating interactions, and s00 and
alpha are used as a bond breaking criteria. The units of c are such
that c/distance = stiffness/volume^2, where stiffness is
energy/distance^2 and volume is distance^3. See the users guide for
more details.
</P>
<HR>
<P><B>Mixing, shift, table, tail correction, restart, rRESPA info</B>:
</P>
<P>This pair style does not support mixing. Thus, coefficients for all
I,J pairs must be specified explicitly.
</P>
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
shift option.
</P>
<P>The <A HREF = "pair_modify.html">pair_modify</A> table and tail options are not
relevant for this pair style.
</P>
<P>This pair style writes its information to <A HREF = "restart.html">binary restart
files</A>, so pair_style and pair_coeff commands do not need
to be specified in an input script that reads a restart file.
</P>
<P>This pair style can only be used via the <I>pair</I> keyword of the
<A HREF = "run_style.html">run_style respa</A> command. It does not support the
<I>inner</I>, <I>middle</I>, <I>outer</I> keywords.
</P>
<HR>
<P><B>Restrictions:</B>
</P>
<P>The <I>peri/pmb</I> style is part of the "peri" package. It is only
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
LAMMPS</A> section for more info.
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "pair_coeff.html">pair_coeff</A>
</P>
<P><B>Default:</B> none
</P>
<HR>
<A NAME = "Parks"></A>
<P><B>(Parks)</B> Parks, Lehoucq, Plimpton, Silling, to appear in Comp Phys
Comm, (2008).
</P>
<A NAME = "Silling"></A>
<P><B>(Silling)</B> Silling, J Mech Phys Solids, 48, 175-209 (2000).
</P>
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