yade-dev team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

> > (As said, I never used that code; what I was driving at was to get
> > comparison of critical timestep given by PWaveTimeStep and
> > GlobalStiffnessTimeStepper.)
> Actually, the relation between the two is relatively weak.
> In short, they scale the same way, but the factor between them depends 
> on (always the same set) porosity, contact anisotropy, PSD,...
Obviously; I just wanted to establish relations in some limit cases,
such as hexagonal dense packing -- to see how much it p-wave
over/underestimates what GSTS gives. P-wave critical timestep is, from
what I gathered, routinely used in continuum dynamics, and for people
with that background, it would be nice to show the correspondence.

(I will probably let it be, since it would be specific to the concrete
model, where I use what I thought was used everywhere, i.e.
crossSection=π*min(r₁,r₂)² ;-) )

> The weak point is GS gives nothing when there is no contact, 
> thats why I use both in scripts now. PW gives an initial value, and GS 
> adjusts it dynamicaly once contacts are created.
That was exactly the reason why I used it -- the initial estimate.
Besides, GSTS was broken for me back then (and I never checked again if
it is OK now).

Cheers, v.