LIGGGHTS® - User Forum

There are predefined granular models provided in the LIGGGHTS Docs. Can I define the new model to use instead of using given models.
I want to use hooke/stiffness model but with a little modification. Can I do that ?

on doc page for gran model hooke/stiffness given description is

{
gran model hooke/stiffness

Syntax:

model hooke/stiffness [other model_type/model_name pairs as described here ] keyword values

zero or more keyword/value pairs may be appended to the end (after all models are specified)

Hi

I am new to LIGGGHTS and would like to ask the possibility of using this tool for DEM analysis of fibre reinforced clay soils where we need to define physico-chemical interactions between two clay particles (i.e., Van der waals and double layer forces) . Is this package suitable for this purpose?

I will be really pleased if experts can give me an idea.

Kind Regards
Mehdi

I just started out with LIGGGHTS and after running some of the standard tutorials, I found this Bin Flow turorial, which should work but is not working for me at the moment

Included is my case folder and when running this I get the following error:

Hello, (warning: new to liggghts.....)
I would like to add bonds to the particles from the hopper drain example.
Specifically I would like to bond multiple atoms together to create a ridged
group with the ability to break if a certain force is exerted on the bond.

I have attached a txt file that contains the tutorial script with added changes and both the input file
and script for the attempt at using atom style hybrid bond granular

Any help is greatly appreciated.

Hi!

I am looking for a possibility to account for heat generation due to friction. I have found the following commands that I think they are connected with this issue: heating_normal_hertz/hook and heating_tangential_history. Unfortunately in both cases the link to surface heating "surface sphere/heatable" is a dead one.

Hi everyone,

I want to simulate a remote interaction between particles and a bond's breakage situation when the tensile is over a certain limit. How can I do that?

I feel dumb but when logged in it says go to bottom of page for download - missing!!!!!

JB Perth Australia

Hi everyone,

when using gran model hooke/stiffness, I noticed that the gamman and gammat specified are weird for the case of absolute_damping = 'off'.
In another dem code PFC, the parameter specified for viscous damping is damping ratio, however liggghts gives the expression:
gamma(n)=m(eff)*gamma(n,specified)
I wonder if this gamma(n,specified) has a specific meaning that I ignore.

In PFC ,the expression is:
gamma(n)=2sqrt[m(eff)*kn]*gamma(n,specified)
and the gamma(n,specified) is called damping ratio in the normal direction.

thank you.