LIGGGHTS® - User Forum

Hello,

I know I recently opened a topic but I think this question requires another discussion.

I am trying to run simulations of fine powder, with particle dimension described by a Gaussian distribution with mean value of 50 microns.

I want insert a plate, restrain it in Z direction, and load with a force, but I want the force just loaded in part of the surface of the plate. Could I realize this idea in liggghts ?

Hello,

I recently started to use LIGGGHTS.
I am trying to optimize as best as I can the script to run the model. Since some locations of the domain of the simulation are never occupied by particles, I thought to split the domain in multiple partitions, allocating less CPUs for those partitions where particles never go.

Hi,

I'm just wondering if anyone could give me a hint, where the prefactor in the hookean standard model, 16/15*..., results from?
Following the work of Di Renzo (2004) (see. refs on the Hooke doc site), where kn is calculated from

kn = fn,max / deltan,max, i only get the prefactor of 4/3. Maybe someone could give am a clou.

Thanks,

M

Dear Christoph, Dear users,

just wonder if the read_data command works for multi-sphere feature? If yes, what is the data file format? read_data works for molecule atom style, but I found atom style molecule and multisphere are not compatible . Thanks,
Cheers,
Zyan

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}