LAMMPS (12 Feb 2007) # 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 box = (0 0 -0.283174) to (56.6348 43.1615 0.283174) 1 by 1 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 110 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 2 860 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 1422 atoms in group mobile set lo-fixed atom 4 150 settings made set hi-fixed atom 4 150 settings made # 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 100 dump.friction run 20000 Memory usage per processor = 1.53816 Mbytes Step Temp E_pair E_mol TotEng Press Volume 0 0.1 -3.1332695 0 -3.0920674 -1.3452097 1384.4128 1000 0.088253389 -3.0560474 0 -3.0196852 0.050420633 1384.4128 2000 0.087864125 -3.0547262 0 -3.0185243 -0.67004561 1384.4128 3000 0.10557467 -3.0607837 0 -3.0172848 -0.221612 1384.4128 4000 0.085491315 -3.0478702 0 -3.012646 -0.42154648 1384.4128 5000 0.10534884 -3.051862 0 -3.0084561 -0.087935136 1384.4128 6000 0.10556767 -3.0559544 0 -3.0124583 -0.54210169 1384.4128 7000 0.098711954 -3.0590419 0 -3.0183705 -0.42838742 1384.4128 8000 0.11529691 -3.0366296 0 -2.9891248 -0.4457814 1384.4128 9000 0.1 -3.0333227 0 -2.9921206 -0.49174903 1384.4128 10000 0.11644796 -3.04181 0 -2.993831 -0.41991946 1384.4128 11000 0.1051652 -3.0340308 0 -2.9907005 -0.61535665 1384.4128 12000 0.10761127 -3.0351207 0 -2.9907826 -0.30937044 1384.4128 13000 0.11361189 -3.0354003 0 -2.9885898 -0.44289723 1384.4128 14000 0.11530172 -3.037545 0 -2.9900383 -0.31673329 1384.4128 15000 0.098629121 -3.0397602 0 -2.9991229 -0.44569024 1384.4128 16000 0.10525229 -3.0429476 0 -2.9995815 -0.29935796 1384.4128 17000 0.10467455 -3.0381932 0 -2.9950651 -0.48920299 1384.4128 18000 0.10817926 -3.0402364 0 -2.9956643 -0.37596363 1384.4128 19000 0.10816167 -3.0452456 0 -3.0006808 -0.35822139 1384.4128 20000 0.11364667 -3.0448494 0 -2.9980246 -0.40159119 1384.4128 Loop time of 39.1823 on 1 procs for 20000 steps with 1722 atoms Pair time (%) = 28.9006 (73.7594) Neigh time (%) = 1.39861 (3.5695) Comm time (%) = 0.380868 (0.972041) Outpt time (%) = 3.67569 (9.381) Other time (%) = 4.82651 (12.3181) Nlocal: 1722 ave 1722 max 1722 min Histogram: 1 0 0 0 0 0 0 0 0 0 Nghost: 146 ave 146 max 146 min Histogram: 1 0 0 0 0 0 0 0 0 0 Neighs: 14398 ave 14398 max 14398 min Histogram: 1 0 0 0 0 0 0 0 0 0 Total # of neighbors = 14398 Ave neighs/atom = 8.36121 Neighbor list builds = 728 Dangerous builds = 0