LIGGGHTS® - User Forum

Hello and good morning/afternoon,
I have a few questions related to the timings LIGGGHTS outputs to the screen/log file at the end of a run as well as some scalability issues im facing.
So i'm running granular simulations of around 500 000 particles discharging in an hopper. I ran the simulation 10 and 100 timesteps with different number of cores to gauge scalability. I used the most recent LIGGGHTS version in Ubuntu 18.04LTS.

Dear CFDEM users,
I need to define two atm types, however, I faced an error.
ERROR: Fix property/global (id m1): Fix property/global: Length not correct for variable youngsModulus, length should be equal to 1 (= number of atom types) (/build/liggghts-QCz4in/liggghts-3.3.1+repack1/src/fix_property_global.cpp:244)
Here is the material properties definition:
Material properties required for granular pair styles
fix m1 all property/global youngsModulus peratomtype 5.e6 5.e6
fix m2 all property/global poissonsRatio peratomtype 0.45 0.45

Hi There,

Hi everyone,
I am doing a simulation in which flow properties are changing with time. Is there any way to give the flow properties as a function of time.

Hi everyone.
I am working on a simulation that involves several impacts between particles; to gain a better understanding of the impact phenomenom I simulated a single impact between 2 particles and I noticed that although the friction coefficient was put to 0 and the coefficient restitution to 1, the conservation of energy and linear momentum was not respected.
Can I ask why? Is it related to the mechanism that the software uses to compute the contact forces or there may be some conceptual mistake I've made?
Thank you for your help

Dear all,
I want to simulate bonded material, can somebody give me some initial tutorial showing how to simulate bonded material.

For questions about Electrostatic force, please post here!

Dear all,

I am trying to add image support to LIGGGHTS. Based on the instructions found in the documentation, I believe I should be able to add the following lines to the Makefile.user file:

LMP_INC=-DLAMMPS_PNG
JPG_INC=-I/opt/pkg/filelib/libpng/1.6.34/gnu/7.2.0/64/opt/include/libpng16
JPG_PATH=-lpng
JPG_LIB=-L/opt/pkg/filelib/libpng/1.6.34/gnu/7.2.0/64/opt/lib

However, when trying to compile LIGGGHTS, I recieve the following error:

I have tried to push the v3.7.0 with BONDS (provided by Mr./Dr. m*****) to v3.8.0.

And I have met some issues. One of the key issues is how to set the random seed in fix bond create. Does anyone has experience on solving this issue?

Thanks!