LIGGGHTS® - User Forum

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.

Hello everyone,

i am trying to make a unixal compression stress test using ligggths and i get below error when i am running my script.Does anyone has any idea to how to fix below error:
The servo-wall requires a contact model. Therefore, it has to be used for a fix wall/gran too

my code is as below:

#### Writen for LIGGGHTS ritchi with bond ##########################################################

Hello LIGGGHTS forum,

I am still confused about deciding proper grain kinematics for my simulation. Could I get some help?

I am using three different types of particles with radius 0.03, 0.02 and 0.01 (in si unit) for a drum like sagmil simulation (for test simulation only).
Currently I am defining poision ratio = 0.3, cofficient of restiturion=0.6, sliding friction = 0.2, rolling friction = 0.1.
Density of grain is 2500 kg/m3, fillmass = 120 kg.

Hi every one

i am planning to compress a box with inserting a topwall and with below command put pressure on a stl wall wit 10 N force.however i get below error:

Reading STL file '3by3_Plate.stl' (mesh processing step 1/3)
ERROR on proc 0: Illegal situation in MultiNodeMesh::registerMove (../multi_node_mesh_I.h:373)

Here is my script:

#### ##########################################################

Hello,

I am running a simulation where I need to make a specific particle move with a specific linear velocity, and no rotation.

I use "fix move" command to set the linear velocity of the specific particle "intruder" as:

fix dragging intruder move linear ${vx} NULL NULL

But I don't know how to prevent the intruder from rotating on the basis of this. Do anyone know about this?

Thanks

Hello, experienced LIGGGHTS users,

Hello everybody, I am newbie in Liggghts. I am working on Particle insertation. My code failed after certain points. I couldn't figure out what to do:

variable dia1 equal 6
variable dia2 equal 2
variable rad1 equal ${dia1}/2
variable rad2 equal ${dia2}/2

variable startPercent equal 0.8

variable rad1_start equal ${rad1}*${startPercent}
variable rad2_start equal ${rad2}*${startPercent}