Rolling friction model

Submitted by tshan on Tue, 06/14/2011 - 15:12

Hi Christoph,

I want to ask about what rolling friction model is used in LIGGGHTS. And what is the typical value of rolling friction coefficient for sand?

Thanks in advance!

Best,
Tong

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JF's picture

JF | Tue, 06/14/2011 - 15:33

Hi tong,

There is no model which uses rolling friction in LIGGGHTS. However, Christoph helps me to implement lattice beam theory and I can give some hints to implement the sphere rotation and rolling stiffness in your contact model.

Concerning the value of rolling stiffness for your simulation you can read this famous article:

Rolling Resistance at Contacts in Simulation of Shear Band Development by DEM (written by M.Oda)

However, I can already tell you that you have to find this value from validating numerical tests, once your model works.

JF

ckloss's picture

ckloss | Tue, 06/14/2011 - 16:42

Hi Tong and JF,

there _is_ a rolling friction model, and it can be classified as a "Directional constant torque model". See the following review paper from Jin Ooi's group: Powder Technology 206 (2011) 269–282

JF, thanks for the literature reference, I did not know that one

>> And what is the typical value of rolling friction coefficient for sand?
I think you can't say it that way - every grain of sand is different!

>>However, I can already tell you that you have to find this value from validating numerical tests, once your model works.
That is our experience, too. You can e.g. vary the coefficient to match the angle of repose

Cheers,
Christoph