forked from lijiext/lammps
91 lines
1.9 KiB
Plaintext
91 lines
1.9 KiB
Plaintext
# 2d friction simulation
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dimension 2
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boundary p s p
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atom_style atomic
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neighbor 0.3 bin
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neigh_modify delay 5
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# create geometry
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lattice hex 0.9
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region box block 0 50 0 22 -0.25 0.25
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create_box 4 box
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mass 1 1.0
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mass 2 1.0
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mass 3 1.0
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mass 4 1.0
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# atom regions
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region lo-fixed block INF INF INF 1.1 INF INF
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region lo-slab block INF INF INF 7 INF INF
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region above-lo block INF INF INF 7 INF INF side out
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region hi-fixed block INF INF 20.9 INF INF INF
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region hi-slab block INF INF 15 INF INF INF
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region below-hi block INF INF 15 INF INF INF side out
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region lo-asperity sphere 32 7 0 8
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region hi-asperity sphere 18 15 0 8
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region lo-half-sphere intersect 2 lo-asperity above-lo
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region hi-half-sphere intersect 2 hi-asperity below-hi
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# create 2 surfaces with asperities
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create_atoms 1 region lo-slab
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create_atoms 1 region hi-slab
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create_atoms 2 region lo-half-sphere
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create_atoms 3 region hi-half-sphere
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# LJ potentials
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pair_style lj/cut 2.5
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pair_coeff * * 1.0 1.0 2.5
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# define groups
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group lo region lo-slab
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group lo type 2
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group hi region hi-slab
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group hi type 3
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group lo-fixed region lo-fixed
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group hi-fixed region hi-fixed
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group boundary union lo-fixed hi-fixed
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group mobile subtract all boundary
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set group lo-fixed type 4
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set group hi-fixed type 4
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# initial velocities
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compute new mobile temp/partial 0 1 0
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velocity mobile create 0.1 482748 temp new
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velocity hi set 1.0 0.0 0.0 sum yes
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# fixes
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fix 1 all nve
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fix 2 boundary setforce 0.0 0.0 0.0
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fix 3 mobile temp/rescale 200 0.1 0.1 0.02 1.0
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fix_modify 3 temp new
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fix 4 all enforce2d
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# Run
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timestep 0.0025
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thermo 1000
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thermo_modify temp new
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#dump 1 all atom 500 dump.friction
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#dump 2 all image 500 image.*.jpg type type &
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# zoom 1.6 adiam 1.5
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#dump_modify 2 pad 5
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#dump 3 all movie 500 movie.mpg type type &
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# zoom 1.6 adiam 1.5
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#dump_modify 3 pad 5
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run 20000
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