LIGGGHTS® - User Forum

Hi everyone,

For my M.Sc. Thesis, I am interested in using dynamic groups, using LIGGGHTS 3.3.1 (public).
Is this somehow possible?

According to the group command, this should not be possible, but maybe I am not looking the most updated link
http://www.cfdem.com/media/DEM/docu/group.html

any suggestion would more than welcome.

Greetings, Luca

Dear all,

newly, I tried to use pair_style hybrid gran model hertz history coul/cut ** in LIGGGHTS3.3.1, it does not work, which worked in earlier version.

Could I still simulate the coulombic force in LIGGGHTS3.3.1?

best regards

Zhen

Hi everyone,

I am trying to model a cone penetrometer test (CPT) in a volume of sand and I would like to compute cauchy stresses in order to get shear lines but I can't find a way to do that. I don't think that the command compute/stress gives that kind of results.

Is there a way to compute them using Liggghts?

Regards,

Abdellah

Hello all,
fix move all move/mesh mesh cad1 rotate ... rotates the mesh along the axis specified.
for eg: motion similar to rotation of earth around the sun can be done using the above fix.

My question is: Is there any fix to define the motion similar to moon roationg around earth where it is tidally locked.

Perhaps you can understand better if you see the picture attached. I would like to get motion similar to the bottom half of the pictue.

cheers,
manton

I want to specify two friction angles for a simulation - one for between pairs of grains, and a lower one between grains and walls. For preliminary simulations, I have been using the following to define friction:

fix m4 all property/global coefficientFriction peratomtypepair 1 ${intfriction}

it is not diffcult to build liggghts by Visual Studio by nmake command, can office source code give a .sln file ?

Hi everyone,

- is it possible to relate cohesive energy density (CED) to surface energy (gamma), or are they calculated completely differently ?

- I understand that the values of CED is calibrated experimentally. What I am trying to do now is to find an estimation range for CED to some pharmaceutical powder. So, is it possible to find some of these values directly somewhere or do I need to do some experiments before I can use this model for my powder ?

Thanks in advance,

Luton

Hi every one....!
i am trying to simulate a mixer that contain glass beads with impeller in the middle.I am a new user of LIGGGHTS. i want to simulate wet mixing with 4 % moisture content,my problem is that i don't know how to add moisture content in the attached input file.Attached file is actually for dry mixing. My system contain 27000 glass beads with 3 mm dia.

Thanks every one.

Hello everybody,

each simulation run it appears the following warning after the "Setting up run...".

WARNING: Energy calculated for multisphere particles is currently not correct (../fix_multisphere.cpp:1014)

Does everyone knows how to solve the problem ?
A typical multisphere command in my code looks like this :

fix ms1 all particletemplate/multisphere 1 atom_type 1 density constant 1566 nspheres 552 ntry 1000000 spheres file data/mstemplate scale 0.001 type 1

Thank you!

Command ”compute pair/gran/local" calculates a local array, of witch the row number equals the number of pairs. So how to get the exact rows on a specified step?
thankyou