LAMMPS WWW Site - LAMMPS Documentation - LAMMPS Mailing List Archives
[lammps-users] Problem in Tensile Testing of Nanocomposite
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[lammps-users] Problem in Tensile Testing of Nanocomposite


From: Jit Sarkar <jitsarkar1993@...24...>
Date: Thu, 26 Oct 2017 15:47:24 +0530

Dear All,

I have designed a nanocomposite having one silicene layer reinforced between two graphene layers. I wnat to perform the tensile test of this composite. The load value in the log file during tensile testing is starting from much higher value (in the range of 189) instead of from zero or a very low value as expected in a tensile test. Also the stress value is fluctuating between positive and negative values. The cfg file also shows that the layers are getting distorted during the test.

Please find the program attached for convenience.

Please let me know your suggestions.

Thanks
Best Regards,
JIT
____________________________________________________
Jit Sarkar (B.Tech)
Junior Project Assistant & Research Scholar (MS)
Department of Metallurgical and Materials Engineering
Indian Institute of Technology, Kharagpur-721302, India
Phone- +919476414445
# Program for thermal equilibration followed by tensile deformation of a cylindrical nanoparticle



#--------------Initialize Simulation-------------------
echo screen
dimension	2
units           metal
atom_style      atomic

#--------------Create Atoms----------------------------

boundary p s p

region	box block 0.0 100 0.0 500 -10 15 units box
create_box	2 box

lattice   custom 2.465 a1 1.0 0.0 0.0 a2 0.5 1.0 0.0 &
basis 0.0 0.0 0.0 basis 0.25 0.25 0.0

region	graphene block 0.0 100 0.0 500 0.0 7 units box
create_atoms	1 region graphene

lattice   custom 3.8453 a1 1.0 0.0 0.0  a2 0.5 1.0 0.0 &
basis 0.0 0.0 0.0  basis 0.25 0.25 0.0

region	silicene block 0.0 100 0.0 500 1 3 units box
create_atoms	2 region silicene 

set region silicene type 2

mass 1 12.011
mass 2 28.086

group lower id < 8273
group upper id > 41362
group middle id <> 8272 41363


#--------------Define Interatomic Potential--------------

pair_style	tersoff
pair_coeff	* * SiC.tersoff C Si 

#--------------Run the simulation for equilibration-----------------

velocity all create 298.0 873847 rot yes dist gaussian
fix 1 all nvt temp 298.0 298.0 0.01 

timestep 0.001

thermo		10
thermo_style	custom step pe ke etotal temp lx ly lz press atoms

dump 1 all cfg 1000 NP_GS.*.cfg mass type xs ys zs 
dump 2 all custom 10000 dump.NP_GS mass element type x y z vx vy vz
log log.NP_GS_EQM

run 20000

#----------------MD Run for tensile deformation-------------

fix 3 lower move linear 0.0 0.0 0.0 units box
fix 4 upper move linear 0.0 2.0 0.0 units box

timestep 0.001

compute 1 upper com
compute 2 lower reduce sum fy
compute 3 middle temp

thermo		1
thermo_style	custom step c_1[2] c_2 c_3

dump 3 all cfg 1000 NP_GS.*.cfg mass type xs ys zs 
dump 4 all custom 10000 dump.NP_GS mass x y z vx vy vz
log log.NP_GS_DEFORM

run 500000


###