LIGGGHTS® - User Forum

Hi, all,
I am trying to put atoms that meet a certain boolean condition to a group called "inwardatom". This is the code:

variable eatom2 atom "(v_DH>50e-6)&&(v_inOut<0)"
group inwardatom variable eatom2

The error message says:

ERROR: Illegal group command (group.cpp:341)

Can anyone tell me what causes it?

Thanks a lot!

Hello,
I have a question regarding 'heat/gran' command.
In the example code of heat transfer, f_heattransfer is set as one of output.
What is the unit of f_heattransfer? J? or J/s?
If it is energy [J], should the heat rate be calculated by using time step?
Thanks in advance.

Hi Guys

So this is not a technical query. I wanted to know how many people use LIGGGHTS for mining related work?

I have used LIGGGHTS for my MSc where I studied the efficiency of a new type of vibrating screen, noting that material handling is not my field of work, I am actually a structural engineer.

Hello, I am a new user of LIGGGTHS public.

I am working on a project which involves a variable speed belt. However, I couldn't find an example or detailed explanation on this.

How can I simulate this with LIGGGTHS public?

Could anyone shade a light on this? I think this is a common problem in a real project?

Thanks.

Hello,

I used compute pair/gran/local in order to find the contact area between two superquadrics. The output gives me 260 mm^2 while the diameter of the particles is 11 mm. The contact is edge-face, so basically this small overlap between face and edge, according to the output, produced the contact area more than twice the face-to-face total contact between the particles.

The question is what does "contactArea" exactly represent? What are the possible reasons why the contactArea found is so large?

Thanks everybody for Your replies in advance!

Hello guys,
Recently I am having a problem in particle insertion in drum.

I don't have problem with small size of particles with small drum. However, I am trying to use a bigger drum with width 2m and diameter 6m (si unit).
For bigger geometry I am trying to insert two types of particles with 1 m and 0.8 m. Whenever I increased the particles size, it doesn't increase the required number of particles in insertion. Instead it just insert 10, or 12 particles. I gues it is trying to control some of the calculation like fill mass rate or insertion.

Hello,
I am running a simulation that needs a hertzian contact force, as well as a SJKR cohesion force and a capillary cohesion force. I cannot get both cohesion forces to work in the same simulation. This is the command I am using.

pair_style hybrid/overlay gran model hertz tangential history cohesion sjkr cohesion easo/capillary/viscous
pair_coeff * *

And I am receiving this error:

ERROR: Unknown argument or wrong keyword order: 'cohesion' (../pair_gran_base.h:129)

Any help would be great thank you!

I am looking into how I would go about modifying an existing contact model to include charge conduction of particles through contact. I have to say my C++ skills aren't amazing but I have a fair bit of experience with programming in other languages so I understand how code is set up and run. My confusion comes from understanding where I would have to implement this code in order to allow for charge to be transferred when particles collide with each other and where I would put the calculations that are referred to during this interaction.

Hi everyone,

I faced an error when I try to push down (like hydrogel_multicontact tutorial) my particles.
When the number of particles are small the error not occured, but I have to increase the number of particles.

Thank you for your attention!

Here is the output. I cannot figureout the meaning of sidata.deltan.