LIGGGHTS® - User Forum

Hi

I am working on the modelling of SLM. I am actually a total beginner. I would be glad if anyone can help through with the steps involved in the simulation. I have understood that I need to make use of Liggghts to simulate the powder particles and then couple it with OpenFoam to simulate the moving heat flux/laser. I would be really glad if someone can provide with a sample input file, so that I have something to start off with.

Thanks
Ojas

Hi, I tried to apply the bonding model to my LIGGGHTS.

I downloaded the LIGGGHTS-WITH-BONDS at github (https://github.com/richti83/LIGGGHTS-WITH-BONDS), and also found the bondsfalloncone example at github (https://github.com/Polyun/LIGGGHTS-PUBLIC/tree/master/bondspackage/bonds...).

Hi, I was looking for the meaning of the "hard_particle yes" command needed for high young's modulus and I don't find the answer. I thought that means the same that hard-sphere, contact by impulsive forces instead of overlap but that doesn't have sense, because I can use hard_particle at the same time as the hertz model that work with overlaps.
I hope someone can help me to understand why this command must be used

I have adapted the compute conts function to make contact calculations for a model that depends on the surface contact area between contacting particles. For superquadrics however, the rsq <= radsumsq condition in compute_contact_atom.cpp overestimates the contact time when the superquadric contact point is not at the maximum radius for both particles. The correct calculation of deltan (total deformation) for superquadrics is needed to make this work properly. For particle-wall contacts this is much easier to find, see :

Hello friends, greetings.

I'm looking for the rotating drum tutorial in which the wall is made of particles. By any chance, any of you have a copy of in.* file?
Or
Any such files where we have a wall of particles moving / rotating? I want to understand the setup. Eagerly waiting for your reply.

Thank you,
Jagan Mohan.

Hi
I would like to count the collision frequency between different types of particles in each time step.
i have 16 types of particles :
i did manage to count for each type, but what i need is to count for example :
Between Type 1 and Type 1, between Type 1 and Type 2 ...., between Type 16 and Type 16.
here is my code :

Hi,

I am wondering if developers are on their way to implementing SJKR forces on superquadric particles.

This would be really useful for some of my simulations.

Best regards,

Oier.

Hi
In my simulation, I am using three types of atoms (say 1,2,3) I need to define the contact stiffness between each of them (E1,E2, E3)
For that I am using the following
fix m1 all property/global youngsModulus peratomtype ${E1} ${E2} ${E3}

As far as I can understand, this command has assigned a young modulus to each of the particles. How it takes care say when atom 1 and 3 come in contact. Is there a way to assign contact modulus like that? I tried peratomtypepair but it did not work.

Thanks
Shubham

Hi
I am using LIGGGHTS - flexible fibers version
I am defining a prism region using the following command:
variable dummy2 equal 1.01*${beam_length}

region bc_blade prism ${dummy2} ${dummy2}+${blade_particle_diameter} -${blade_particle_radius} ${blade_particle_radius} 0 ${blade_length} 0 0 ${blade_particle_radius} units box

All the variable are defined tin the code, however I am encountering the following error;
Illegal region prism command

How it can be solved??

Hi
I would like to count the collision frequency between different types of particles in each time step.
i have 16 types of particles :
i did manage to count for each type, but what i need is to count for example :
Between Type 1 and Type 1, between Type 1 and Type 2 ...., between Type 16 and Type 16.
here is my code :