LAMMPS (22 Jan 2008) # 2d friction simulation dimension 2 boundary p s p atom_style atomic neighbor 0.3 bin neigh_modify delay 5 # create geometry lattice hex 0.9 Lattice spacing in x,y,z = 1.1327 1.96189 1.1327 region box block 0 50 0 22 -0.25 0.25 create_box 4 box Created orthogonal box = (0 0 -0.283174) to (56.6348 43.1615 0.283174) 2 by 2 by 1 processor grid mass 1 1.0 mass 2 1.0 mass 3 1.0 mass 4 1.0 # atom regions region lo-fixed block INF INF INF 1.1 INF INF region lo-slab block INF INF INF 7 INF INF region above-lo block INF INF INF 7 INF INF side out region hi-fixed block INF INF 20.9 INF INF INF region hi-slab block INF INF 15 INF INF INF region below-hi block INF INF 15 INF INF INF side out region lo-asperity sphere 32 7 0 8 region hi-asperity sphere 18 15 0 8 region lo-half-sphere intersect 2 lo-asperity above-lo region hi-half-sphere intersect 2 hi-asperity below-hi # create 2 surfaces with asperities create_atoms 1 region lo-slab Created 750 atoms create_atoms 1 region hi-slab Created 750 atoms create_atoms 2 region lo-half-sphere Created 112 atoms create_atoms 3 region hi-half-sphere Created 112 atoms # LJ potentials pair_style lj/cut 2.5 pair_coeff * * 1.0 1.0 2.5 # define groups group lo region lo-slab 750 atoms in group lo group lo type 2 862 atoms in group lo group hi region hi-slab 750 atoms in group hi group hi type 3 862 atoms in group hi group lo-fixed region lo-fixed 150 atoms in group lo-fixed group hi-fixed region hi-fixed 150 atoms in group hi-fixed group boundary union lo-fixed hi-fixed 300 atoms in group boundary group mobile subtract all boundary 1424 atoms in group mobile set group lo-fixed type 4 150 settings made for type set group hi-fixed type 4 150 settings made for type # initial velocities compute new mobile temp/partial 0 1 0 velocity mobile create 0.1 482748 temp new velocity hi set 1.0 0.0 0.0 sum yes # fixes fix 1 all nve fix 2 boundary setforce 0.0 0.0 0.0 fix 3 mobile temp/rescale 200 0.1 0.1 0.02 1.0 fix_modify 3 temp new # Run timestep 0.0025 thermo 1000 thermo_modify temp new dump 1 all atom 500 dump.friction run 20000 Memory usage per processor = 1.69136 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 0.1 -3.1333672 0 -3.0921549 -1.1440307 2444.4558 1000 0.08936608 -3.060858 0 -3.0240282 0.015747058 2444.4558 2000 0.087353242 -3.0615115 0 -3.0255112 -0.49966222 2444.4558 3000 0.097185838 -3.0626106 0 -3.0225581 -0.084736345 2444.4558 4000 0.10514697 -3.0540883 0 -3.0107549 -0.34379432 2444.4558 5000 0.10965701 -3.0502726 0 -3.0050804 0.13242136 2444.4558 6000 0.1142368 -3.0461587 0 -2.9990791 -0.23407787 2444.4558 7000 0.1 -3.038824 0 -2.9976117 -0.3283908 2444.4558 8000 0.11116944 -3.0485104 0 -3.0026949 -0.42926135 2444.4558 9000 0.11429391 -3.0445555 0 -2.9974523 -0.39751757 2444.4558 10000 0.10617044 -3.050964 0 -3.0072087 -0.4320286 2444.4558 11000 0.10925063 -3.0492538 0 -3.0042291 -0.39877306 2444.4558 12000 0.11491574 -3.0511726 0 -3.0038132 -0.24990158 2444.4558 13000 0.10704872 -3.0467833 0 -3.0026661 -0.4272322 2444.4558 14000 0.10931685 -3.0488184 0 -3.0037664 -0.23385297 2444.4558 15000 0.103619 -3.0474073 0 -3.0047036 -0.39914954 2444.4558 16000 0.11669382 -3.0538214 0 -3.0057292 -0.29282079 2444.4558 17000 0.10983692 -3.0489199 0 -3.0036536 -0.30423885 2444.4558 18000 0.11157946 -3.0516854 0 -3.005701 -0.3165345 2444.4558 19000 0.11408792 -3.0522616 0 -3.0052433 -0.39019198 2444.4558 20000 0.10714842 -3.0629068 0 -3.0187485 -0.2392859 2444.4558 Loop time of 11.275 on 4 procs for 20000 steps with 1724 atoms Pair time (%) = 2.6525 (23.5254) Neigh time (%) = 0.125193 (1.11036) Comm time (%) = 6.57651 (58.328) Outpt time (%) = 0.108834 (0.965266) Other time (%) = 1.81201 (16.071) Nlocal: 431 ave 483 max 383 min Histogram: 1 1 0 0 0 0 0 1 0 1 Nghost: 100 ave 118 max 84 min Histogram: 1 0 0 1 0 1 0 0 0 1 Neighs: 3600.5 ave 4171 max 3180 min Histogram: 2 0 0 0 0 0 1 0 0 1 Total # of neighbors = 14402 Ave neighs/atom = 8.35383 Neighbor list builds = 724 Dangerous builds = 0