Hello.
I want to move a dislocation by shear stress.
I used the following command.
But it didn’t seem to work.
Dislocation in my model didn’t move at all.
Would someone tell me where the problem is?

``````# ---------- BOUNDARY ---------------------
variable THICKNESS equal 3.0
variable LOWER_END equal (bound(all,zmin))
variable UPPER_END equal (bound(all,zmax))
variable LBOUND equal \${LOWER_END}+\${THICKNESS}
variable UBOUND equal \${UPPER_END}-\${THICKNESS}

# ---------- GROPUS ---------------------
region lowerBlock block INF INF INF INF INF \${LBOUND}
region upperBlock block INF INF INF INF \${UBOUND} INF
group top region upperBlock
group bot region lowerBlock
group bounds union top bot
group body subtract all bounds

compute peatom all pe/atom

# ---------- RIGID BOUNDARY ---------------------
fix 2 top setforce 0.0 0.0 0.0
fix 3 bot setforce 0.0 0.0 0.0

# ---------- Initial_System ---------------------
reset_timestep 0
write_dump all cfg initial*.cfg mass type xs ys zs modify sort id element Al

# ---------- Apply_Shear_Strain ---------------------

variable i loop 20
label loop1
#displace_atoms top move  0.01 0.0 0.0 units box
#displace_atoms bot move -0.01 0.0 0.0 units box
fix shear1 top addforce 2e-04 0 0
fix shear2 bot addforce -2e-04 0 0
minimize 0.0 0.001 50000 50000

print "@ \${i}"

reset_timestep \${i}
write_dump all cfg shear*.cfg mass type xs ys zs modify sort id element
next i
jump shear_static.in loop1

print "All done."
``````

You are running a minimization of your system 20 times with the same external force.
Why should there be a change once the system is minimized?

Thank you.
I’ll do so.