I am not sure whether the way I measure the stress is right

Dear all,

I deformed a parallel hexahedron cell by dragging the two ends toward two opposite directions along z-coordinate with a constant velocity. Then I use pzz as the stress in z-coordinate. I am not sure whether it is right.

Best regards,

Liu Bo

Input file for uniaxial tensile loading of nano-partical composites

Mark Tschopp, November 2010

--------------------------- units ----------------------------------

units real

dimension 3

atom_style full

boundary p p p

timestep 1

--------------------------- force field ----------------------------

pair_style lj/class2/coul/long 10 10

bond_style class2

angle_style class2

dihedral_style class2

improper_style class2

kspace_style pppm 1e-4

dielectric 1.0

special_bonds lj 0 0 1 coul 0 0 1 dihedral yes

----------------------- atom definitionh ---------------------------

read_data data.LayerOH

region 1 block 0 21.608 0 19.64 43.0 53.0 units box

region 2 block 0 21.608 0 19.64 -2.0 8.0 units box

group fixedtop region 1

group fixedbottom region 2

group boundary union fixedtop fixedbottom

group mobilezone subtract all boundary

----------------------- initialize velocity ------------------------

velocity all create 1 7655 rot yes dist gaussian

velocity all zero linear

----------------------------- modify -------------------------------

neighbor 0.3 bin

neigh_modify every 2 delay 10 check yes

----------------------- thermo setting -----------------------------

thermo 500

thermo_style custom step temp press pe ke etotal vol lx ly lz pxx pyy pzz pxy pxz pyz

timestep 1

------------------------- EQUILIBRATION ----------------------------

minimize 1e-16 1e-16 1000000000 10000000000000

------------- quench (Run for at least 10 picosecond) --------------

Constant NPT time integration via Nose/Hoover

reset_timestep 0

fix 1 all npt temp 300 300 1 iso 0 0 1 drag 1

run 30000

unfix 1

What answer are you looking for other than what the doc
page says that it calculates?

Steve

also, it looks as if you’re using (at least partly) one of the evo wiki tutorials. these are quite well documented and explain quite nicely explained. so together with the LAMMPS doc pages you should have your answer.

best,

nikita