LIGGGHTS® - User Forum

hi
I run some of the examples of liggghts yesterday but today I can't run them and here is the command and the error .

saeed@ubuntu:~$ ~/Documents/LIGGGHTS-PUBLIC/src/lmp_openmpi < in.movingMeshGran
bash: in.movingMeshGran: No such file or directory

thanks so much

I am using LIGGGHTS but it uses only one processor for computing. I have installed LIGGGHTS by following http://cfdem.dcs-computing.com/?q=node/1789

None of the combination like processors 1 2 1 or processors 2 1 2 works...

Don't know whether LIGGGHTS is not multi-processor because no processor settings were made during compilation. Do I need to install LIGGGHTS with some added settings or feature can be added later.

Hello,

Hi all,

No doubt this is very simple, but I don't know Linux well enough to know what's going on.

I have gone through the :official" installation tutorial for Fedora on this website, everything seemingly went smoothly until the last step:

+ Set a following symbolic link for LIGGGHTS (use lmp_fedora if you use the fedora makefile):
+ Type "sudo ln -s /path1/src/lmp_fedora /usr/bin/liggghts"

I ran this command from the home directory with path1 replaced with LIGGGHTS-PUBLIC, which gives an error 'symbolic link already exists'.

pair/gran/hooke and wall/gran/hooke does not work correctly. For example, the source "pair_gran_hooke.cpp" contains lines number 197-206 with the code:

// force normalization

fn = xmu * fabs(ccel*r);
fs = gammat*vrel;
if (vrel != 0.0) ft = MIN(fn,fs) / vrel; ======== ??? ========
else ft = 0.0;

// tangential force due to tangential velocity damping

fs1 = -ft*vtr1;
fs2 = -ft*vtr2;
fs3 = -ft*vtr3;

Hi everyone,
I have tried to calculate the velocity of particles based on their position, but the results show that the velocities which I calculated are exactly twice the dumped velocity. I have checked the time interval, I used the real time as follows:
"real time=timestep*No. of steps"
I was wondering if anyone has any idea why this happens?or what am I doing wrong?

Cheers,
Mahsa

I am performing a long-running simulation in LIGGGHTS. It has approx 10,00,00,000 steps and dump files are written per 1000 time-steps. Working with such huge number of files, it becomes really difficult to perform lpp processing of all at a time. If I need to check the progress while the simulation is on the go everytime above command starts from beginning which is clearly a waste of time. Also, if any interruption happens or error comes then I have to perform lpp from beginning with the command lpp dump*.mixer.

Hi,

I want to simulate the material behaviour on a vibrating tray. I search for a feature which allows me to insert the particles which leave one side of the simulation on the opposite site. For insrance if the material on the tray moves from left to right and reaches the right end of the simulation the particles are moved to the left side (e.g. if xpos > 100 then xpos = xpos - 100).

Is there anything like this available or do I need to modify code to reach simulate this? I do not have experience in modifying or add commands.

Thanks in advance,

Urs

Hi,

I'd like to compress a box includes particles in all 6 directions. For doing that I have to build six (6) 2-D plate (stl file) and use "mesh/surface/stress/servo" for every plate. Is it true?
Or, I can build a 3-D box and compress in all 6 directions. If it is possible, would you please inform me how can I do that.

Best Regards,
Rasoul

Is there a LIGGGHTS capability to take a particle under given conditions and split it / replace it with several smaller particles? I'm specifically looking for a solution within the "granular" atom-style world (but it could be a hybrid style).

I could have sworn I saw an example of this a few months ago, but I can't find it now. Was this the multisphere capability? (node/20 illustrates multiple particles bonded together, but I want one particle that splits into multiple independent particles).

Thanks!