LAMMPS (9 Jan 2009) # 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 -3.0921259 -1.1440102 2444.4558 1000 0.081958665 -3.0927273 0 -3.0589265 -0.021850399 2444.4558 2000 0.082641883 -3.0850764 0 -3.0509938 -0.44968978 2444.4558 3000 0.092293442 -3.0748001 0 -3.0367371 -0.25358115 2444.4558 4000 0.096012911 -3.0565129 0 -3.0169159 -0.027674947 2444.4558 5000 0.1 -3.0465555 0 -3.0053142 -0.09934336 2444.4558 6000 0.11642983 -3.0390782 0 -2.991061 -0.21038719 2444.4558 7000 0.11597773 -3.0331763 0 -2.9853456 -0.46354951 2444.4558 8000 0.11937916 -3.0305564 0 -2.9813229 -0.30779256 2444.4558 9000 0.11110731 -3.0274253 0 -2.9816032 -0.5245514 2444.4558 10000 0.11533593 -3.0167931 0 -2.969227 -0.3589085 2444.4558 11000 0.11347587 -3.0130738 0 -2.9662749 -0.47723571 2444.4558 12000 0.10688909 -3.0229092 0 -2.9788267 -0.31337183 2444.4558 13000 0.11881914 -3.0191983 0 -2.9701958 -0.43871352 2444.4558 14000 0.10970971 -3.0345115 0 -2.9892658 -0.26475254 2444.4558 15000 0.10683593 -3.030202 0 -2.9861414 -0.37883026 2444.4558 16000 0.11039182 -3.0315771 0 -2.9860501 -0.31830843 2444.4558 17000 0.11294566 -3.0314496 0 -2.9848693 -0.34449141 2444.4558 18000 0.11747267 -3.0330363 0 -2.984589 -0.21439976 2444.4558 19000 0.11287946 -3.0392425 0 -2.9926895 -0.38778831 2444.4558 20000 0.10942894 -3.0360473 0 -2.9909174 -0.3375786 2444.4558 Loop time of 10.2058 on 4 procs for 20000 steps with 1724 atoms Pair time (%) = 2.6057 (25.5315) Neigh time (%) = 0.123432 (1.20942) Comm time (%) = 5.74675 (56.3086) Outpt time (%) = 0.113881 (1.11584) Other time (%) = 1.61606 (15.8347) Nlocal: 431 ave 494 max 376 min Histogram: 1 0 1 0 0 0 1 0 0 1 Nghost: 95 ave 124 max 75 min Histogram: 1 1 0 0 1 0 0 0 0 1 Neighs: 3578.5 ave 4170 max 3130 min Histogram: 1 1 0 0 0 1 0 0 0 1 Total # of neighbors = 14314 Ave neighs/atom = 8.30278 Neighbor list builds = 703 Dangerous builds = 0