LIGGGHTS® - User Forum

Hi Guys

I am trying to use the rotate/variable command as per the below implementation.

fix move2 all move/mesh mesh cad rotate/variable origin 0. 0. 0. axis 1. 0. 0. omega 1

I get the following error when trying to execute my code.

ERROR: Variable name 1 for fix move/mesh rotate/variable does not exist (../mesh_mover_rotation.cpp:174)
(../mesh_mover_rotation.cpp:174)

Can someone please assist with the issue at hand?

How can I get a particle velocity profile across a channel? Is there any specific command?

Hi,

I am working with the EEPA/Edinburgh contact model and due to the lack of doc something is unclear to me.

There are two input stiffnesses called CoeffAdhesionStiffness and UnloadingStiffness. I was unable to exactly determine what the value of the CoeffAdhesionStiffness (kn2kc) should be as it is not used the same way in the original work by Morrissey. In the code it is used to multiply with the loading stiffness to get the adhesion stiffness:

k_adh = kn2kc[itype][jtype] * kn

Hi Guys

This is just my baby steps for a more complex model which I would like to simulate.

I am trying to move a mesh translationally and rotationally at the same time.
Currently I am using the chute_wear model to achieve this.

The code that I am using is shown below, only the rotational movement is being produced.
How can I achieve the motion?

fix move all move/mesh mesh cad wiggle amplitude -0.01 0. 0. period 0.02
fix move all move/mesh mesh cad rotate origin 0. 0. 0. axis 0. 0. 0.1 period 0.05

Hello everyone!
I have a problem with compiling a script in LIGGGHTS due to problems with STL file. I have tried many CADs, such as SolidWorks, Blender, Salome, but all the constructions can't be compiled with an error "Bad mesh, Can't continue".
It works well in Aspherix by using element_exclusion_list command due to excluding one triangle. However, in LIGGGHTS I can't fix this problem.

Hi Guys

I am new to LIGGGHTS. I have ran through some of the examples.

I would like to know if the "fix move/mesh command" can be used to move mesh at a specific acceleration. The movement and acceleration will vary according to time and the data is kept on an excel spreadsheet.

Kind regards
Mishal Mohanlal

Hello
I am using LIGGGHTS-flexible fibres.
I my simulations I need to group certain atoms based on a spatially non uniform function. Since difficult to implement in LIGGGHTS directly, I plan to extract the atom IDs using a Python/Matlab script, then define grouping of those specific atoms. I have following two questions in this regard:
1) Is it possible to use group command such that I can group specific atoms read from a text file ?
2) What is the template to store atom IDs in such a text file ?

Any suggestions will be highly appreciated

Hi there,
I am trying to implement a drag force on particles flowing through a hopper with a upper cylindrical section and lower conical section. The drag force is to be calculated based on "void fraction" around each particle, then scaling of superficial velocity of the gas by the void fraction, and then getting value of Reynolds number, coefficient of drag, inputing into formula for drag. Snippet of the code is given below. I am facing some issues.

Hello, there is a way as shown in the examples to grow spherical particles in a packing...can the same be done for superquadric particles?

Hello is there a way to make all the particles inertialess? Can someone please help with the same?