Dear LAMMPS Users,
I am doing a research project on granular materials and I am using the in.pour file to output information. I am using the information from the dump commands to create the simulation of dumping granular particles into a container in Python.
My questions are the following:
1. when my particles output as an image, some of the particles are overlapping, which makes the simulation not look very realistic. I believe that this is set with pair_style command but when i change the values for the normal repulsion force, my output remains the same. Here is what my pair_style line looks like : pair_style gran/hooke/history 2000.0 NULL 50.0 NULL 0.5 0
What i did was changing the 2000.0 to 2.0e5 and also changing the timestep, but that does not seem to fix the problem.
I also looked at the special_bonds and bond_ style command, but since I am new to LAMMPS Im not sure what I need to do.
Any ideas on what I could do so that my particles don’t overlap?
Here is what my in.pour file looks:
atom_style sphere
boundary p p fm
newton off
communicate single vel yes
region reg block -10 10 -10 10 -0.5 16 units box
create_box 1 reg
neighbor 0.2 bin
neigh_modify delay 0
# IMPORTANT NOTE: these values of stiffness (2000) and timestep (0.001)
# are used in this example file to produce a quick simulation and movie.
# More appropriate values for realistic simulations would be
# k = 2.0e5 and dt = 0.0001, as in bench/in.chute.
pair_style gran/hertz/history 2.0e5 NULL 50.0 NULL 0.5 0
pair_coeff * *
timestep 0.0001
fix 1 all nve/sphere
fix 2 all gravity 1.0 spherical 0.0 -180.0
fix zlower all wall/gran 2000.0 NULL 50.0 NULL 0.5 0 &
zplane 0.0 2000.0
region slab block -9.0 9.0 -9.0 9.0 10.0 15.0 units box
fix ins all pour 3000 1 300714 vol 0.13 50 region slab
compute 1 all erotate/sphere
#compute 2 all coord/atom 3.0 * *
#compute 2 all property/local patom1 patom2
#compute 2 all pair/local fx fy fz
thermo_style custom step atoms ke c_1 vol
thermo 1000
thermo_modify lost ignore norm no
compute_modify thermo_temp dynamic yes
dump id all custom 10000 dump.pour6 id type x y z radius
#dump 2 all image 1000 image.*.jpg type type &
# axes yes 0.8 0.02 view 80 -30
#dump_modify 2 pad 5
#dump 3 all movie 1000 movie.mpg type type &
# axes yes 0.8 0.02 view 80 -30
#dump_modify 3 pad 5
run 250000
unfix ins
fix 2 all gravity 1.0 chute 26.0
run 250000
Thank you so much for you time,
Ignacio