LIGGGHTS® - User Forum

Hi all,
I'm trying to install liggghts in ubuntu but I've had some troubles. When I type "sudo apt-get install openmpi openmpi-devel" shows up the follow message :

Leyendo lista de paquetes... Hecho
Creando árbol de dependencias
Leyendo la información de estado... Hecho
E: No se ha podido localizar el paquete openmpi
E: No se ha podido localizar el paquete openmpi-devel

In order to get over this problem I followed instruction that I found on internet:

Hi,

HAPPY NEW YEAR ;)

I have successfully compiled balance.cpp and balance.h and then I recompiled CFDEM to introduce balance command to it. Now static load balancing command is activated in LIGGGHTS-PUBLIC and It works very well. Also I check it on the Cluster and everything seems fine.

But when I tried to run CFDEM I faced with the following errors. Then I separably checked ligghts in two state : 1. without restart file 2. with restart file. It seems when information read from restart file liggghts crashes.

Any one has any idea ???

Hi,
I am a beginner of LIGGGHTS, I always met such termination of the program,like this:

Hi everyone!
I have trouble to use fix pour command! The related script is just like this:

region beads block -0.1 0.1 -0.1 0.1 0.1 0.3 units box
fix 4 all pour 2000 1 300719 region beads vol 0.13 50 diam 0.01 0.01

I don't think there are any problems,but liggghts doesn't recognize this as a valid fix style(ERROR: Invalid fix style (modify.cpp:710)). This really confused me! Can you help me? Thanks a lot!

Regards!
Mike

Hi,all
I have a question. I want to simulate particles pouring into a cone. But some problems really confused me!
From the manual on this website :http://nf.nci.org.au/facilities/software/LIGGGHTS/doc/fix_wall_gran.html, I should make the input script like this:
fix conewall all wall/gran/hertz/history 0 0 zcone 0 0.2 0.05 0.1 1
But the LIGGGHTS tells me that "Need to use define style 'mesh' or 'primitive' (fix_wall_gran.cpp:224)"

Another beginner question:

I'd like to output the total number of atoms per timestep. This can already be in the thermo_style output so can be extracted from the log file by editing out all the other compute comments and warnings, but this is a little tedious.

Is there a way to either suppress the comments during the solve or write out the thermo_style output to a separate file? Or perhaps put the atoms # into the dump file?
thanks.

hi
Is it possible to model the interaction of two CAD files? for example in a case: rotating one CAD file may cause rotating another CAD file.

Thanks

My models can't endure with high pressure those particles will penetrate inside the models (particle go through the model when simulate at high pressure i can understand because it makes sense but some times low pressure also). In actually it shouldn't penetrate. I would like to ask you how to make model strong? I think it should has some parameters in LIGGGHTS that can make a wall strong enough for endure with high pressure simulation.

Thank you,
terces907

Another beginner question: I'd like a normal distribution of particle sizes with a mean of 0.000925m and a standard deviation of 0.1.

I've tried this:
fix pts1 all particletemplate/sphere 1 atom_type 1 density constant 2900 radius gaussian number 0.009525 0.1
fix pdd1 all particledistribution/discrete 1. 1 pts1 1.0

but I get this:
ERROR: Probablity distribution: mu-3*sigma < 0, please increase mu or decrease sigma (probability_distribution.h:169)

Do I need to put sigma = (0.009525*0.1)?

Hi, Christoph:

I am doing a simulation involving chemical reaction of particles. In the simulation, I have to update some material properties, such as Young's modulus, Poisson's Ratio, and friction coefficients.... These coefficients must be changed according to their early values (on the last time step), so that I can implement a calculation like:

S_new=S_old+1

When I do it by using the 'variable atom' commands, errors always take place. This algorithm is easy to implement in C++ or other languages. But, it becomes a wrong statement in Liggghts. Do you know why?