yade-dev team mailing list archive

[Janek Kozicki <janek_listy@xxxxx>]

Frederic introduced this double radius.

And it has a reasoning and derivation from formulas. Problem is that
I can't remember now this derivation. But When I reproduced his
derivation it actually made sense to use double radius for flat
surfaces. Maybe Frederic remembers and we can ask him.

I can only recall that it has something to do with
- penetration depth
- point of contact
- stiffness

and from this derivation a sphere in contact with "mirror" double
radius sphere behaved exactly the same as if it was in contact with
flat surface. Maybe that also had something to do with shearing, but
I'm not sure now). A critical point in this derivation was that the
double radius spheres was moving & following (=="mirror") the real
sphere that was in contact with flat surface.

I can't recall this now.

best regards
Janek Kozicki

Klaus Thoeni said:     (by the date of Tue, 13 Dec 2011 23:00:24 +1100)

> Well if it is 1 for boxes now I don't see any reason why it should be 2 for 
> facets. Or is there a reason? Any other opinions? 
> 
> On Tue, 13 Dec 2011 10:46:31 PM Bruno Chareyre wrote:
> > > thanks for the active discussion. So I guess we just leave it as it is
> > > and use 2 for boxes and facets if this is the usual assumption.
> > 
> > It is 1 for boxes now (and good like this). I didn't know 2 was "usual".
> > I would make it 1 for facet as well, but since I'm not using facets a
> > lot, I can't decide for others.
> > 
> > Bruno
> > 
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-- 
Janek Kozicki                               http://janek.kozicki.pl/  |