LIGGGHTS® - User Forum

Hi all

I'm a new user of LIGGGHTS 2.2. I'm trying to build a simulation to calculate slury flow with large particles.
Unfortunately I have one problem. I need to change the drag force on the particle with the velocity. (Ex. drag = 0.0 when v = 0.0, drag = 1.0 when v > 0.0 ) So I try to use the if-statement in the script but I can not access to the velocity information of the particle in the if statement. I don' why. Maybe I guess if-statement part is no good.

Please give me advise and helpful information !

# Slary Flow in Inclined Pipe

Hi everyone,
I am using sjkr and sjkr2 cohesion model in my simulation, but I cannot find any reference about these two models. Could anyone provide me some information about how those models are derived from the JKR model ?

Best,
xpqiu

Hi everyone, I have a question.
The command compute contact/atom define a computation that calculates the number of contacts for each atom in a group.

The contact number is defined for finite-size spherical particles as the number of neighbor atoms which overlap the central particle, meaning that their distance of separation is less than or equal to the sum of the radii of the two particles.

For spherical particles, all with the same diameter, the maximum contact number should be 6, but I've got also 7,8 or 9 contacts. Is it possible?

Hello,

My final year part time master thesis is based on the shrinkage problem during the HIP (Hot Isostatic Pressing) process, which is based on my actual working experiences using the HIP process for an offshore oil and gas project.

Consequently I have a constructed the same dimensional cylinder (large volume cylinder) in autoCad Inventor replicating the same overall dimensions as previously used for this project. My thesis aim is to determine the various packing density values in the cylinder when raw particles are poured into the cylinder.

Hi Everyone,

For my simulations I'm slowly growing the simulation domain using a change_box command with scaling in the z direction.

The docs tell me that "the mapping of processors to the simulation box is not changed from its initial 3d configuration".

Does this mean that the processors on the z boundaries of the domain get the extra simulation domain? If so, is there a clever way to perform a "fools" load balancing step?

Thanks in advance,

Victor

Hello, I’m trying to incorporate LIGGGHTS for simulating a specific type of powder mixer. I’m using SolidWorks 2016 for creating the 3D geometries involved. In addition, I’m utilizing Paraview for post-processing purposes. Having read the user manual for LIGGGHTS, from what I understood the geometry files used in the execution script must be saved as ASCII STL format and that LIGGGHTS does not support Binary STL formats. When I attempted to open the ASCII files in Paraview the software stopped responding. Therefore, I can only view Binary files in Paraview.

Hi all,

I am using the particletemplate/multisphere command to create clumps. The command allows the use of self-defined inertia tensor and mass.
I need to adjust also the center of mass. Currently LIGGGHTS uses the monte carlo method to calculate the center of mass.
Does anyone knows how to set the center of mass individually?

Thanks

I m trying to create a group based on the particle size, which will be used to postprocessing for mass fraction evaulation. Can anyone give me a guide.
Thanks in advance.

Dear all

In LIGGGHTS, I want to model a servo wall that compact particles till a specified stress is acting on the mesh. how can I do this? is it possible by mesh/surface/stress/servo??? as I know this fix cotrolls total force acting on the mesh.
any help would be appreciated.
Regards

Tala,

Hello,

I am following the tutorial to install LIGGGHTS post processing :

When I run :
"./install.sh" in the LPP directory I get an error saying :
directory '/home/daniel/bin' not found
create directory or choose different install directory using the -p flag

How should I fix this issue ?

Thanks.

Best regards,
Daniel