LIGGGHTS® - User Forum

Hello,
I'm pretty new with rigid bodies and have some question about it.
First the project. I want to insert rigid bodies with 4 atoms and "free" particles together in an system.
I have written an script, that inserts rigid bodies continuously and it works so far.
But after a time, some rigid bodies fall apart.

Hi guys,

I had a query about moving mesh in 2d.
I created granular particles on a lattice and imported a mesh from CAD, and moved that mesh. However, as soon as the mesh got close to the atoms and before they could interact, LIGGGHTS gave an error!

ERROR on proc 0: Internal error (../tri_mesh_I.h:108)
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.

Hi guys,

I'm in a bit of a messy situation.

I have a long simulation running (been running for 18hrs +) and did not use restart or write restart command.
I specified a mass of 290 kgs of particles to be input (loose packing) and it is currently only at 88 kgs (after 18 hours, current timestep 1600 out of 2850).
There's warnings of less particles being inserted and its not going to reach 290 mass for sure (hardly inserting any more mass).
I was wondering if I should just abort the simulation. I am in a huge dilemma.

What should I do?

Dear All

How I can change the temperature of inserted mesh after first temperature definition by mesh/surface?

Regards;
Esmaeil

Hi everyone,

Firstly, Thank you to Christoph Kloss and team for developing the newest LIGGGHTS PUBLIC upate (LIGGGHTS 3.2.0).

I had a simple query; will 2d simulations no longer be supported?

Fix pour and fix pour legacy have been removed, and they were commands for liggghts 2d particle insertion.

Unless my assumption is wrong, and those aren't the only fix commands for inserting particles in 2d?

Cheers everyone.

Thanks,

Kevin

Hi everyone,

Can anyone provide details about the best way to get a micron level dia spherical interstitial packing inside a specific area of a cylinder. Interstitial in the sense that the smaller particles should fill the spaces between bigger ones.

Regards
Hari

Hi,

I'm using the epsd2 model for rolling resistance. I know that it adds a resistance moment against rotation, but does it also transfer this moment to the next particle? So is the torque transferred from one particle to the next?

Kind regards
Joshua

Dear all,

I was trying to understand how the overlap can be measured in LIGGGHTS if we have two spheres in collision. I know that I can find the value of the overlap through this equation (from the positions):
Overlap= d-r ;

But actually I am looking for the original equation that has been used in the source to compute the overlap for any collision.

I would be very grateful if you could provide me with any information (equation or paper or book) about computing the overlap in DEM .

Many thanks,
Abdul

Hi,
I want to model a wire in a spiral scheme (like a wire-reinforced membrane) that encloses some particles. the wire should interact with particles and should be able to deform . If bond atomstyle is applicable here what should I add to the code to effectively simulate the interactions. Is there any example in this case?

Any suggestion will be regarded
mojgan

Hi
I am trying to generate a very loose packing by radius expansion method. I pack smaller particles randomly and then assign a friction coefficient (i.e 0.24 in my case) and allow the particles to grow up to a desired radius. consequently, the consolidation procedure is modeled. The method does not result in a very loose pack and the void ratio does not differ significantly from that in a specimen with a friction coefficient of 0.0. the code is as follows