LIGGGHTS® - User Forum

Dear all,
i guess i found a wrong information in the documentation regarding the fix insert/rate/region command.
The corresponding list of general_keywords and their parameters contains the following line:
"once = value to signalise that isertion takes place only once (the step after the fix is issued)"

The value "once", however, is not allowed with this command, as my bash output was:
"'insert_every' = once not allowed"

Hello,
for a simulation, which uses spherical and non spherical particles,
I want to use a singelesphere and a multisphere approach at the same time.
But it does not work.
Every time, when "fix multisphere" starts, all of the existing singlespheres are deleted.
When the multisphere starts first, the simulation crushes shortly after the singlespheres are inserted,
saying
ERROR on proc 0: Too many neighbor bins (../neighbor.cpp:1778)
In both cases, the singlespheres and multispheres are seperated in two different groups and

hy friends....!

Hello, I would like to change the random position of particles before starting a simulation (I want to do different simulations only changing the starting distribution, just to compare average quantities).
Anyway I am changing the seed number in:
- particletemplate/sphere
- particledistribution/discrete
- insert/pack
in all these 3 commands and anything change! Impossible, there is surely a bug. What I see is that seed is not working.

Thank you,
rob1

Hi,

I was wondering if it is possible to apply/modify the gravitational field to particles after they cross a certain spatial coordinate. Based on what i have seen this could be done by creating groups of particles after they enter a certain region, but i can't seem to make it work.

Any thoughts on this?

Thanks,
Nicolas

Good morning,

I would like to create a gaussian distribution of particle sizes, but in particletemplate/sphere only a 'constant' radius is permitted.
What do you suggest?

Thanks a lot and have a nice day,
rob1

Dear Users,

i was trying to densify a loose packing of multisphere clumps using the fix deform command. I was surprised that this command didnot work for a multisphere sample. the simulation boxed was shrunk but the positions of the spheres and clumps was not changed. Does some one have the same issue?

It worked fine for a packing of spheres.

Regards,
zyan

Hi everyone,

I am looking into LIGGGHTS to do some screw conveyor simulations and I have been trying to run the Continuous mixer examples from this site as a starting point.

I understand they where written in the older version of Liggghts, I have been modifying the input script with the updated syntax fro version 3. I have come up against problems regarding the mesh that is supplied in the example.

I get the following error when I try to run the script:

hello every one ....

If I want to refer to the x direction normal stress at time increment 1 as the variable, sx. How can I accomplish this?

My goal is to set up a conditional statement so that if sx>1000, then something else applies.