LIGGGHTS® - User Forum

Hello folks,
I am trying to simulate linear and rotational motion of roller through code but not getting these motion together, The code that I have run is the following :

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fix Moveroller all move/mesh mesh roller rotate origin -0.2 0. 0.118 axis 0. 1. 0. period 0.966645 #second
fix MoveRoller all move/mesh mesh roller linear 0.65 0.0 0.0 #cm/s
run 200000
unfix MoveRoller

######

Hello everyone,

Hi Guys

I am from South Africa, with our power issues (load shedding) I am unable to perform my required analysis on LIGGGHTS. The simulations take far too long and once the power cuts my simulation essentially stops. I know about the restart files however with the input file I have it is not feasible to use the restart routine.

I am able to rent an Ubuntu Server locally which would fit my needs. Has anyone been able to install LIGGGHTS on Ubuntu Server?
I know there is no GUI for Ubuntu server however this can be installed from what I understand.

Hello, I have the problem that I regularly get a "Segmentation fault" in my simulations. When I start the simulations several times, some of them run without problems. But most of them abort with a "Segmentation fault".
I use a cluster on which PBS is. The CPU is a Xeon E5-2630 v3 of which I use 16 cores. Liggghts version LIGGGHTS-PUBLIC 3.8.0.

Hi,

I am trying to build Liggghts 3.8.0 on Ubuntu 21.10 using make auto and get an 'invalid static cast' error. I attached a screenshot of my code for your reference. I looked for this error but did not find any related questions on the forum. Can you please help me resolve it? Thank you in advance.

I want to apply capillary forces to the particles, so that I particles attract each other. How shall I achieve that like what model shall I use? and what other properties do I need to manipulate? Any leads will be appreciated.

Hi Guys

I have a situation where I need to measure the mass of particles which are divided into two types, each type has a range of particles.
Below is the code which I developed. I have made a group called "large" which consists of type 1.
When I try and print out the mass of the type 1 particles and resulting csv file only has 0 values.

I do get results when changing the "large" to "all" when measuring the mass, however this does not help me.
Can someone please assist in explaining where I went wrong.

Hi Guys

I read through the documentation, however I would just like to clarify my understanding.

Is the following correct considering the code presented below:
1. The total amount of particles for the simulation will be 1000
2. The mass rate will be 21.38kg/sec and this will be inserted for every single time step

Hello everyone,

I am running the Direct Shear Test and attempting to calculate the effective stress from the contact forces, as given in Potyondy and Cundall 2004.
Is there anyone that has successfully computed effective stress from the contact forces and compared them with the externally-induced effective stress (normal force/loading area)? Can you recommend me where to start?

Hello,
I am using LIGGGHTS to simulate a simple granular flow condition in which at first particles are inserted in a cuboidal space and one side of this cuboid is removed to allow granular flow. But I am not getting the values of kinetic energy, potential energy, coordination number from 'compute' command. Further, the same is not getting shown in Paraview. Please find the code.

atom_style granular
atom_modify map array
boundary f f f
newton off

communicate single vel yes
processors * * *

units si