forked from lijiext/lammps
71 lines
1.9 KiB
Plaintext
71 lines
1.9 KiB
Plaintext
.. index:: compute smd/hourglass/error
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compute smd/hourglass/error command
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===================================
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Syntax
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""""""
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.. parsed-literal::
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compute ID group-ID smd/hourglass/error
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* ID, group-ID are documented in :doc:`compute <compute>` command
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* smd/hourglass/error = style name of this compute command
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Examples
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""""""""
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.. parsed-literal::
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compute 1 all smd/hourglass/error
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Description
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"""""""""""
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Define a computation which outputs the error of the approximated
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relative separation with respect to the actual relative separation of
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the particles i and j. Ideally, if the deformation gradient is exact,
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and there exists a unique mapping between all particles' positions
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within the neighborhood of the central node and the deformation
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gradient, the approximated relative separation will coincide with the
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actual relative separation of the particles i and j in the deformed
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configuration. This compute is only really useful for debugging the
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hourglass control mechanim which is part of the Total-Lagrangian SPH
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pair style.
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See `this PDF guide <USER/smd/SMD_LAMMPS_userguide.pdf>`_ to use Smooth
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Mach Dynamics in LAMMPS.
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**Output Info:**
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This compute calculates a per-particle vector, which can be accessed by
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any command that uses per-particle values from a compute as input. See
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:ref:`How-to discussions, section 6.15 <howto_15>`
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for an overview of LAMMPS output options.
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The per-particle vector values will are dimensionless. See
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:doc:`units <units>`.
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Restrictions
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""""""""""""
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This compute is part of the USER-SMD package. It is only enabled if
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LAMMPS was built with that package. See the :ref:`Making LAMMPS <start_3>` section for more info.
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This quantity will be computed only for particles which interact with
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tlsph pair style.
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**Related Commands:**
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:doc:`smd/tlsph_defgrad <compute_smd_tlsph_defgrad>`
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Default
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"""""""
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.. _lws: http://lammps.sandia.gov
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.. _ld: Manual.html
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.. _lc: Section_commands.html#comm
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