A Question on graphen bending rigidity

Dear all.

In my project, I used from a paper which has obtained to bending rigidity in the rippled nano ribbon graphen and of course that paper has worked with the NAMD method and now I want to do it in a sheet. I imposed force to the sheet (and I increase the force on the time scale) with using a cylindrical indentor but the sheet is broken very soon. I would expect that the sheet break at the end of the run. My purpose from doing this procedure is to primarily calculate:

Sheet replacement in 2ns and afterwards the extend of replacement with respect to proportion of entered force and the extend of tension with respect to force and finally the extend of bending rigidity.

echo both
boundary p p s
atom_style atomic
units metal
dimension 3
neighbor 2.0 nsq
neigh_modify every 10 check yes
read_data data23.txt

pair_style hybrid lj/cut 5.0 airebo 3.0 airebo 3.0
pair_coeff * * airebo 1 CH.airebo C NULL
pair_coeff * * airebo 2 CH.airebo NULL C
pair_coeff 1 2 lj/cut 1.0 1.5

mass * 12.001
velocity all create 1 887723 dist uniform mom yes rot yes

group graphene type 1
group diamond type 2
displace_atoms diamond move 0 0 10 units box

region left block INF INF INF 1.0 INF INF units box
group left region left
region right block INF INF 99.6 INF INF INF units box
group right region right
group boundary union left right

fix fix2 diamond setforce 0 0 0
velocity diamond set 0 0 0.0 units box

fix fix1 boundary setforce 0 0 0
velocity boundary set 0 0 0.0 units box

fix fix3 all nvt temp 1 1 0.01

timestep 0.001
thermo 1000
thermo_style custom step etotal ke pe temp press vol
min_style cg
minimize 1.0e-4 1.0e-6 100 1000
dump 10 all atom 1000 dump.lammpstrj
run 5000