"LIGGGHTS(R)-PUBLIC WWW Site"_liws - "LIGGGHTS(R)-PUBLIC Documentation"_ld - "LIGGGHTS(R)-PUBLIC Commands"_lc :c

:link(liws,http://www.cfdem.com)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)

:line

mesh module stress :h3

[Syntax:]

stress stress_keywords stress_values :pre

zero or more stress_keyword/value pairs may be appended  :ulb,l
stress_keyword = {reference_point}, {stress} or {wear} :l
  {reference_point} values = rx ry rz
    rx, ry, rz = coordinates of reference point
  {stress} value = on or off
  {wear} value = finnie or off :pre
:ule

[Examples:]

fix cad all mesh/surface/stress file mesh.stl type 1 wear finnie :pre

[Description:]

This mesh module computes the average normal and shear stresses that the particles in the
fix group exert on each triangle of the mesh is evaluated (which costs a bit of performance).
Also, the total force and torque on the particle is calculated (see output info).
The per-element average normal stress can be dumped into VTK format using "dump mesh/vtk"_dump.html.

With the optional {stress} keyword, stress tracking can be turned off if desired. The
reference point for calculating the body torque can be controlled via the {reference_point}
keyword. The optional {wear} keyword can activates a simple qualitative wear model
({finnie}) - for details on the model, see the seperate /doc/finnie-wear.pdf. The wear coefficient
is divided by the mesh element area, therefore it is independent of mesh size.
The finnie constant k in Eqn. (4.23) has to be specified as follows:

fix id all property/global k_finnie peratomtypepair n_atomtypes value_11 value_12 .. value_21 value_22 .. . :pre

    (value_ij=value for the finnie constant between atom type i and j; n_atomtypes is the number of atom types you want to use in your simulation) :pre

This mesh module is a prerequisite for the following mesh modules

"6dof"_mesh_module_6dof.html :ulb,l
"binning"_mesh_module_binning.html :l
"contact"_mesh_module_contact.html :l
"deform"_mesh_module_deform.html :l
"servo"_mesh_module_servo.html :l
"stress"_mesh_module_stress.html :l
:ule

[Restart, fix_modify, output, run start/stop, minimize info:]

This mesh module stores a global vector with 9 components for access by various
"output commands"_Section_howto.html#4_15. The first 3 components are equal to the
total force on the mesh, the next 3 components store the total torque on the body
exerted by the particles. Finally, the last 3 components are the coordinates (moved, scaled, rotated) of the reference point. Other info see "fix mesh"_fix_mesh.html.

[Related commands:]

"fix mesh/surface"_fix_mesh_surface.html
"fix wall/gran"_fix_wall_gran.html

[Default:]

reference_point = 0. 0. 0.
stress = on
wear = off
