140 lines
4.5 KiB
Groff
140 lines
4.5 KiB
Groff
LAMMPS (1 Oct 2006)
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# 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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Created box = (0 0 -0.283174) to (56.6348 43.1615 0.283174)
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2 by 2 by 1 processor grid
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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 lo-slab
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Created 750 atoms
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create_atoms 1 hi-slab
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Created 750 atoms
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create_atoms 2 lo-half-sphere
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Created 112 atoms
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create_atoms 3 hi-half-sphere
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Created 112 atoms
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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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750 atoms in group lo
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group lo type 2
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862 atoms in group lo
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group hi region hi-slab
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750 atoms in group hi
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group hi type 3
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862 atoms in group hi
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group lo-fixed region lo-fixed
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150 atoms in group lo-fixed
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group hi-fixed region hi-fixed
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150 atoms in group hi-fixed
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group boundary union lo-fixed hi-fixed
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300 atoms in group boundary
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group mobile subtract all boundary
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1424 atoms in group mobile
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set lo-fixed atom 4
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150 settings made
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set hi-fixed atom 4
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150 settings made
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# initial velocities
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temperature new mobile 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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# 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 100 dump.friction
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run 20000
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Memory usage per processor = 1.4603 Mbytes
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Step Temp E_pair E_mol TotEng Press Volume
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0 0.1 -3.1333672 0 -3.0921549 -1.3466755 1384.4128
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1000 0.08936608 -3.060858 0 -3.0240282 0.018536372 1384.4128
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2000 0.087353242 -3.0615115 0 -3.0255112 -0.58816858 1384.4128
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3000 0.097185838 -3.0626106 0 -3.0225581 -0.099745896 1384.4128
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4000 0.10514697 -3.0540883 0 -3.0107549 -0.40469143 1384.4128
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5000 0.10965701 -3.0502726 0 -3.0050804 0.15587748 1384.4128
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6000 0.1142368 -3.0461587 0 -2.9990791 -0.27554064 1384.4128
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7000 0.1 -3.038824 0 -2.9976117 -0.38655949 1384.4128
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8000 0.11116929 -3.0485103 0 -3.0026949 -0.50529564 1384.4128
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9000 0.11426746 -3.044549 0 -2.9974568 -0.4678125 1384.4128
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10000 0.10652378 -3.0503221 0 -3.0064212 -0.52457375 1384.4128
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11000 0.1102547 -3.0498241 0 -3.0043856 -0.45053087 1384.4128
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12000 0.11548097 -3.0510641 0 -3.0034718 -0.27052982 1384.4128
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13000 0.10919538 -3.0438158 0 -2.9988139 -0.53868739 1384.4128
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14000 0.10742456 -3.045668 0 -3.0013959 -0.25306386 1384.4128
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15000 0.10795006 -3.0436862 0 -2.9991975 -0.44644395 1384.4128
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16000 0.11271512 -3.0478462 0 -3.0013937 -0.28516203 1384.4128
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17000 0.11209577 -3.0497319 0 -3.0035347 -0.39432942 1384.4128
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18000 0.1 -3.050733 0 -3.0095207 -0.34607727 1384.4128
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19000 0.092061676 -3.048521 0 -3.0105803 -0.37268438 1384.4128
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20000 0.10666663 -3.0598394 0 -3.0158797 -0.33025583 1384.4128
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Loop time of 8.99743 on 4 procs for 20000 steps with 1724 atoms
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Pair time (%) = 3.6897 (41.0084)
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Neigh time (%) = 0.202473 (2.25034)
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Comm time (%) = 3.18145 (35.3595)
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Outpt time (%) = 0.579402 (6.43964)
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Other time (%) = 1.3444 (14.9421)
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Nlocal: 431 ave 484 max 381 min
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Histogram: 1 1 0 0 0 0 0 1 0 1
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Nghost: 100.5 ave 119 max 87 min
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Histogram: 1 0 0 2 0 0 0 0 0 1
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Neighs: 3597.5 ave 4163 max 3176 min
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Histogram: 2 0 0 0 0 0 1 0 0 1
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Total # of neighbors = 14390
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Ave neighs/atom = 8.34687
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Neighbor list builds = 720
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Dangerous builds = 0
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