Obtaining P-h curve from nanoindentation test

Dear lammps user

Hello

I want to simulate nanoindentation on iron.

But I got stuck on obtaining P(load)-h(displacement) curve.

Here below is my scripts.

In my scripts, I just calculated potential energy and force of each direction (x, y, and z). but these values are not a indentation force

I really need your helps.

Thanks in advanced.

------------------- INITIALLIZE -------------------

units metal

dimension 3

boundary p p s

atom_style atomic

----------------- ATOM DEFINITION -----------------

lattice bcc 2.8

region sample block 0 100 0 100 0 100 units box

create_box 1 sample

create_atoms 1 region sample

mass 1 55.845

------------------- FORCE FIELD -------------------

pair_style eam/fs

pair_coeff * * Fe_mm.eam.fs Fe

neighbor 2.0 bin

neigh_modify delay 10 check yes

fix 9 all nvt temp 300.0 300.0 100.0

dump 1 all custom 1 dump.Fe id type x y z

min_style cg

minimize 1e-15 1e-15 5000 5000

run 1

undump 1

region fixed block 0 100 0 100 0 5 units box

group bottom region fixed

fix 5 bottom setforce 0.0 0.0 0.0 region fixed

------------------- Define Settings -------------------

compute csym all centro/atom bcc

compute eng all pe/atom

compute eatoms all reduce sum c_eng

thermo 0

thermo_style custom step temp pe lx ly lz press pxx pyy pzz c_eatoms

-------------------- INDENTATION ----------------------

dump 4 all custom 5 dump.indentation id type xs ys zs c_csym c_eng fx fy fz

fix 3 all indent 100.0 sphere 50.0 50.0 120.0 20.0 units box

fix_modify 3 energy yes

min_style cg

minimize 1e-15 1e-15 5000 5000

fix 3 all indent 100.0 sphere 50.0 50.0 119.9 20.0 units box

fix_modify 3 energy yes

min_style cg

minimize 1e-15 1e-15 5000 5000

fix 3 all indent 100.0 sphere 50.0 50.0 119.8 20.0 units box

fix_modify 3 energy yes

min_style cg

minimize 1e-15 1e-15 5000 5000

¡¦¡¦.(repeated same commands except for z coordination of indenter for further loading)

Dear lammps user

Hello

I want to simulate nanoindentation on iron.

But I got stuck on obtaining P(load)-h(displacement) curve.

Here below is my scripts.

In my scripts, I just calculated potential energy and force of each
direction (x, y, and z). but these values are not a indentation force

I really need your helps.

how about reading the documentation again. in the output section of the fix
indent description is says:

This fix computes a global scalar energy and a global 3-vector of forces
(on the indenter), which can be accessed by various output commands. The
scalar and vector values calculated by this fix are "extensive".

which is what you are asking for.

axel.