Dear steve,

i am trying to repeat the work published by osetsky in “Modelling and simulation in Materials science and engineering,11(2003)427-446”.

1.creation of domain with dislocation has been done.

2.Movement of dialocation at 0 k is also simulated.

But i am unable to get the Criticle resolved shear stress required to move the dislocation at 10K, which is repoted in paper as 25MPa.

i used the following steps in the input file

first the minmization of the domain using minimization commond.

thermal equilibration for 1000 time steps.

applying shear strain of 10^-5 per time step. at the same time dumping the stress values per atom of the upper group of atoms

and dividing by the number of atoms in the group to get avg stresss.(stress/volume)

the above steps are run in loop for 100 times to get 0.1% strain as in the paper.

is it wright?if not plz help me.

The input file using for the simulation is given below

# 3d metal shear simulation os box size 80*50 with dislocation

units metal

boundary p s p

atom_style atomic

lattice bcc 2.855324

read_data FORT.12

pair_style eam/fs

pair_coeff * * Fe_mm.eam.FS Fe

neighbor 2 bin

neigh_modify delay 5

region lower block INF INF INF 0 INF INF

region upper block INF INF 70 INF INF INF

region plot block INF INF 30 40 INF INF

group lower region lower

group upper region upper

group plot region plot

group bound union lower upper

group plot1 union plot bound

group m subtract all bound

# temp controllers

compute new3d m temp

compute str upper stress/atom

compute sum upper reduce sum c_str[4]

compute 1 plot pe/atom

compute 2 plot centro/atom

fix 1 m nve

timestep 0.001

label loopa

variable a loop 200

print “A = $a”

fix 20 bound setforce 0 0 0

minimize 1.0e-10 1.0e-10 20000 20000

min_style cg

velocity m create 10.0 100000 temp new3d

fix 10 m temp/rescale 1 10.0 10.0 2.0 0.5

run 1000

velocity upper set 2 0 0

dump 21 bound custom 1 dump.pecentro.$a id x y z c_1

dump 22 upper custom 1 dump.upperstrs.$a id c_str[4] fx

run 1

undump 21

undump 22

next a

jump in.shear2 loopa

with regards

kiran