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[Jan Stránský <question204014@xxxxxxxxxxxxxxxxxxxxx>]

Question #204014 on Yade changed:
https://answers.launchpad.net/yade/+question/204014

Jan Stránský proposed the following answer:
Hi Christian,

I was only checking the utils module documentation, thanks for the
location.

your facets are not actually dynamic (as far as I see from the script),
because you apply RotationEngine on box and thus prescribe all their
motion, while cylinder is fixed from definition. So from this point of view
PVaweTimeStep is ok.

Anyway, it is always a good idea to use GlobalTimeStepper at least once in
the beginning of your simulation (but, as Brune mentioned, after a few
steps), because PVaweTimeStep computes time step from "young" of spheres,
but each material law handles it in different way (this is also mentioned
in DEM formulation in Estimade dT_cr by vawe propagation), so it might be a
bit dangerous - but you will definitely know it if it was your case :-)

to conclude, use both PVaweTimeStepper and GlobalTimeStepper if you are not
sure about your time step :-) one other option is to set dT manually
O.dt = sqrt( (density * 4/3.*pi*r*r) / young ) # for CpmMat_CpmPhys, in
your case (FrictMat_FrictPhys) it would be different :-)

Jan

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