Stress strain curve

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1

Hi Everybody

I would like to calculate the stress strain curve for Zirconium using lammps.I have used the following input script

log MM.defk.EAM.out
units metal
boundary p p p
atom_style atomic
pair_style eam
read_data hcpl.in
pair_coeff * * Zrncs.eam

mass 1 91.224

regions of sample

neighbor 2.0 bin
neigh_modify every 1 delay 5 check yes

compute new all temp
compute pen all pe/atom
compute ken all ke/atom

timestep 0.0000001
thermo_style custom step temp press vol xlo xhi ylo yhi zlo zhi
thermo 250
thermo_modify lost warn norm yes

dump 1 all custom 1000 MM.defk.EAM.dump id type x y z
dump_modify 1 every 1000

velocity all create 1 585889 temp new

fix 1 all deform 1 x volume y volume z scale 10.1 units box

I am not sure how to take stress vs strain values .Could you please tell me how can I do it

2

Hi Everybody

I would like to calculate the stress strain curve for Zirconium using
lammps.I have used the following input script

log MM.defk.EAM.out
units metal
boundary p p p
atom_style atomic
pair_style eam
read_data hcpl.in
pair_coeff * * Zrncs.eam

mass 1 91.224

# regions of sample

neighbor 2.0 bin
neigh_modify every 1 delay 5 check yes

compute new all temp
compute pen all pe/atom
compute ken all ke/atom

timestep 0.0000001
thermo_style custom step temp press vol xlo xhi ylo yhi zlo zhi
thermo 250
thermo_modify lost warn norm yes

dump 1 all custom 1000 MM.defk.EAM.dump id type x y z
dump_modify 1 every 1000

velocity all create 1 585889 temp new

fix 1 all deform 1 x volume y volume z scale 10.1 units box

I am not sure how to take stress vs strain values .Could you please tell me
how can I do it

have you checked the mailing list archives if somebody
has asked this or a related question before? you can start here:

http://lmgtfy.com/?q=stress+strain+site%3Alammps.sandia.gov

axel.

3

Strain is the box size/shape relative to what
it started at. Since you are deforming the box
explicitly via fix deform, you know that value
at any time. Stress is the pressure of the
system, or some component of the pressure
tensor, which compute pressure calculates.
So you know that at any time as well. It's up
to you to use those values to make a plot.

Steve