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[Bruno Chareyre <question403469@xxxxxxxxxxxxxxxxxxxxx>]

Question #403469 on Yade changed:
https://answers.launchpad.net/yade/+question/403469

    Status: Open => Answered

Bruno Chareyre proposed the following answer:
>"your meaning that there is no physical damping"

I meant that NewtonIntegrator::damping is a numerical trick to slow down
the system. It does not correspond to any law of physics, so you better
don't use that for realistic simulation of granular flow.

> "kinetic energy of particles needs to be dissipated since the energy
dissipation through friction damping during sliding may not be enough"

This is a very common fairy tail, leading to some bad practice. I actually do undamped simulations quite often, in many cases it is completely safe (not always though), and sometimes computationally more efficient (because the loading rate can be increased). So, I'll not try to justify the above claim. Instead, I would say: a problem that "may" occur should not be fixed by making the numerical model physically inconsistent.
I would start pushing the layer without damping. If you observe blatantly excessive bouncing of some elements then you can think of using viscous contacts, else you can just forget the issue I think.

Bruno

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