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

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

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LIGGGHTS 3.X vs. LIGGGHTS 2.X - syntax changes :h1

Introduction: :h2

This is a short outline of the most important changes in LIGGGHTS 3.X 
compared to LIGGGHTS 2.X regarding the syntax of major commands. The 
motivation for these changes was to make the script language more readable and to 
improve extendability (in the sense of object oriented programming) with respect 
to modelling approaches.

Commands covered by this tutorial: :h2

fix wall/gran/* :l
pair_style gran/* :l
:ule

Changes in syntax for each command: :h2

Changes are indicated as follows

OLD: old_syntax
NEW: new_syntax  :pre

where {old_syntax} refers to the syntax used in LIGGGHTS 2.X and before,
and {new_syntax} refers to the syntax used in LIGGGHTS 3.X.

:line

[fix wall/gran/*:]

OLD: fix ID group-ID wall/gran/* {WALL-OPTIONS}
NEW: fix ID group-ID wall/gran {MODEL-SELECTION} {WALL-OPTIONS} {MODEL-SETTINGS} :pre

MODEL-SELECTION :h3
{MODEL-SELECTION} = model {M} \[tangential {T}\] \[cohesion {C}\] \[rolling_friction {R}\] :pre
{M} = hooke | hooke_stiffness | hooke_hysteresis | hertz | hertz_stiffness :pre
{T} = [no_history] | history :pre
{C} = [off] | sjkr | sjkr2 | hamaker :pre
{R} = [off] | cdt | epsd :pre

MODEL-SETTINGS :h3
{MODEL-SELECTION} = \[tangential_damping ([on]|off)\] \[absolute_damping (on|[off])\] \[viscous (on|[off])\] :pre

Examples :h3

OLD: fix ID group-ID wall/gran/hertz/history mesh n_meshes 2 meshes cad1 cad2
NEW: fix ID group-ID wall/gran model hertz tangential history mesh n_meshes 2 meshes cad1 cad2 :pre

OLD: fix ID1 group-ID wall/gran/hooke/history type 1 xplane -0.5
NEW: fix ID1 group-ID wall/gran model hooke tangential history type 1 xplane -0.5 :pre

OLD: fix ID1 group-ID wall/gran/hertz/history primitive type 1 xplane -0.5 rolling_friction cdt
NEW: fix ID1 group-ID wall/gran model hertz tangential history rolling_friction cdt primitive type 1 xplane -0.5 :pre

OLD: fix ID group-ID wall/gran/hertz/history primitive type 1 xplane -0.5 0.5 cohesion sjkr
NEW: fix ID group-ID wall/gran model hertz tangential history cohesion sjkr primitive type 1 xplane -0.5 0.5  :pre

OLD: fix ID group-ID wall/gran/hertz/history primitive type 1 zcylinder 0.05 0. 0. tangential_damping off
NEW: fix ID group-ID wall/gran model hertz tangential history primitive type 1 zcylinder 0.05 0. 0. tangential_damping off :pre

:line

[pair_style gran/*:]

OLD: pair_style gran/* [MODEL-SETTINGS]
NEW: pair_style gran  [MODEL-SELECTION] [MODEL-SETTINGS] :pre

MODEL-SELECTION :h3
Same as in fix wall/gran/*

MODEL-SETTINGS :h3
Same as in fix wall/gran/*

Examples :h3

OLD: pair_style gran/hertz/history
NEW: pair_style gran model hertz tangential history :pre

OLD: pair_style gran/hertz/history rolling_friction cdt
NEW: pair_style gran model hertz tangential history rolling_friction cdt  :pre

OLD: pair_style gran/hertz/history cohesion sjkr
NEW: pair_style gran model hertz tangential history cohesion sjkr   :pre

OLD: pair_style gran/hertz/history tangential_damping off
OLD: pair_style gran model hertz tangential history tangential_damping off :pre

