LIGGGHTS® - User Forum

Hi All,

I am running a simple test case by shooting a single particle on an impact plate using different impact angles, velocities and mass.
At all the dependencies of the velocities and the mass are like expected. I just struggle with the results of varying impact angle, because in my case it doensn´t fit with the theoretical results i would expect by finnie. I attached a picture of the results of the simulation for the wear after impact and the curve i would expect for varying impact angles.

Hello,

I am trying to simulate the interaction (hertz) between a stl mesh (type 2) and an ensemble of particles bonded together (type 1).
I am using:

atom_style hybrid bond sphere
...
pair_style gran model hertz tangential history
pair_coeff 1 2
bond_style harmonic
bond_coeff 1 1000.0 200.0

Why do I get errors in the bond_coeff command? E.g. index out of bound or incorrect args for bond style (if I insert * instead of 1).
Thanks a lot and have a nice day,

rob1

i have typed : sudo apt-get install git
.
.
.
E: unable to locate package git

what should I do now?

Can anyone help me, how to move my wall for 3D consolidation simulation? Thanks in advance.

HI,
Can anybody help me how to find total number of slip events in a time step in granular simulation.
I tried adding a counter in pair_gran_hooke and also a compute flag in compute/pair/gran/local. But it is not working. Can anyone help please.

saikat

Hi all,

I am doing my master thesis (simulation of roller compaction-pharmaceutical powder).

I have verry big problems with high number of particles (mean diameter is 120 µm).

For 1 g of powder I need 700 000 particles. That is a lot because for filling volume of roller compactor I need "rough estimation" 20 milion particles.

So for that many particles I don't have proper hardware.

In roller compactor I must meausre density in specific regions (picture "Density measure").

Hi All,

I have a physical system (fully loaded material bin with stones) which physically discharges the material contents in 95 seconds.

I have the same system in DEM (same physical dimensions for the geometry and particle sizes), with a time step of 1.0E-6 sec. The DEM system completely discharges in 20 seconds (20.0E6 time steps).

I mean to ask if there is a relationship between physical discharge time and simulation time. Is there anything wrong with this simulation? Does the DEM system really need to discharge in 95 seconds as in physical system?

Hi

May someone assist with how to upgrade liggghts to the current version. I am currently using version 3.4

Thank you

Hi

May someone help me with how to compute the total mass of multispheres in the computational domain please.

Thank you

Hi everyone,

I am running a simulation and observe a kinetic energy shift between runs

this is a part of the log file of my simulation. after the following run start, the kinetic energy shift up. what may be the reason? Between two runs, I only add dump command without changing any properties.