Is there a way to turn off friction in gran/hooke/history simulations?

Using the latest version of LAMMPS, is there a way to set frictionless conditions for a simulation?

The closest I can see from the pair_style gran/hooke documentation is to set k_t to zero in order to zero the tangential displacement vector between 2 particles which is truncated to satisfy a frictional yield criterion (\delta s_t).

You can directly set a static yield criterion xmu of zero in pair gran.

Note that the shear force, proportional to k_t, is only present in gran/hooke/history and gran/hertz/history. It is not in the gran/hooke pair style. The tangential damping term, gamma_t, is present in all.

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Thank you for the reply!

Can you please verify if my understand below is correct?

If Xmu is set to zero, then there will be no total tangential force, including both the shear force and the dampening force.

But if my intent is to just drop the shear tangential force and keep the tangential dampening force, “gran/hooke” instead of “gran/hooke/history” should be used.

Is this correct?

Thank you again!

Yes, that sounds correct.