LIGGGHTS® - User Forum

dump dmp all custom/vtk 1000 post2/particle_*.vtk id type x y z vx vy vz
dump_modify dmp every 1000 format "%d %d %.16g %.16g %.16g %.16g %.16g %.16g"
This modify command not working. I want to modify my dump file precision value.

Hi everyone,
I am working on separating magnetic particles from nonmagnetic particles on a vibrating screen. I want to set up magnetic force in LIGGGHTS and see how the particles will behave under the influence of magnetic force. Can anyone suggest how can I develop magnetic field? Please note that I will be using non-spherical dry particles and I will not use any coupling technique.

Hi,
I am working on separating magnetic particles from non-magnetic particles in a vibrating screen. I want to simulate the influence of external magnetic field. Can anyone tell me how to add magnetic force command in LIGGGHTS? My simulation will deal with dry non-spherical particles and I wont use any coupling technique.

Best regards,
Nihal

Dear fellow LIGGGHTS users,

I have been working on a model of superquadric particles that are growing and when they exert a curtain force on each other will bond. The Part that doesn't work, is the bonding of single particles.

I want to bond only particle I and particle J. Is here a way to bond 2 single superquadric particles. Or another way to bond 2 particles that exert a force above a certain threshold on each other?

Thanks for helping!

Hello,

I want to calculate the dissipation energy of particle collision in ball mill over time. I am not able find any command.

"The damping energy is the dissipated energy due to in-elastic contacts between particles and particle/balls/walls and is physically more related to particle breakage"

The specific damping energy at contact i is given by
Wm=
t
∫ F_dn * dε_n/m_i
0
, where F_dn is the normal damping force, dε_n the normal displacement over a whole contact period t and m_i is the mass of the particles.

Thank you.

Hey everyone,

I'm a beginner to LIGGGHTS and C++. I'm currently looking to modify LIGGGHTS to compute and store frictional dissipation at the contacts.

This was supposed to be an easy simulation but I am stuck here.
1) I am inserting particles in cylinder for few seconds
2) After insertion I want to settle it and make a packing in cylinder. My main aim is to fill cylinder more than 80% and make packing tighter.

When I run my script, simulation goes well. But while visualizing it, I see that particles are not piling up in cylinder instead, it penitrate my cylinder buttom and goes out.

I did used f f f boundary condition but I am still not able to fix it.

For sure, my mesh file does have solid buttom.

Hallo,

as i am beginner to the LIGGGHTS. Therefore, I have a basic question regarding simulation time.

I am trying to compute the contact force acting the container wall. The container is under harmonic motion (Wiggle) and is partially filled with steel spherical particles.

If i set the following variable for time step:

hello,

I have a body (mesh) in my system, that I would like to let it have a specific (linear) movement but according to an equation that represents the acceleration and deceleration of it.

The equation is represented by 3 parts, each standing for a time phase, and they are in terms of a variable z.

I want to write a loop, that considers the increase of z by a certain increment that I define and includes three parts representing each equation within a certain time phase.

May you please suggest a way to define such a loop.

Thank you for your support.

Hello everyone,

label loop_growth

run ${grow_every2}

variable curr_dia2 equal ${start_dia2}+step*${grow_rate_dia2}
variable new_z1 equal ${z1}+(${curr_dia2}-${start_dia2})/2
change_box all z final 0.0 ${new_z1} units box

if "${curr_dia2} > ${end_dia2}" then
"jump SELF done_growth"
else
"jump SELF loop_growth"
endif

label done_growth