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Re: Elastic energy


chiara modenese said:     (by the date of Mon, 5 Jul 2010 16:02:45 +0100)

> > 1. I used neverErase flag, because something goes wrong when
> > interaction breaks. So do not delete it, but only reset Fn=0 and Fs=0.
> >
> >  [Law2_ScGeom_FrictPhys_Basic(label='dry',traceEnergy=True,neverErase=True)]
> >
> Good Janek, so you agree there something unexpected is happening once
> calling the function requestErase(). Potential interactions seem somehow not
> deleted and I do not know if this can have any consequence somehow. We
> should definitely check that function which almost every contact law is
> using, most importantly.

Yes, and this function currently is a mystery for me. I guess, that
when spheres aren't in contact, but very close to each other, then
the interaction isn't deleted actually. And the shearForce and
normalForce aren't zeroed either? Just a guess, I don't know.

> >   plasticDissipation +=
> >  (-shearDisp -
> > (1/currentContactPhysics->ks)*(trialForce-shearForce))//plastic disp.
> >  .dot(shearForce);//active force
> >
> This is weird because as I already said to me plasticDissipation code looks
> right as it is. I would not be able to prove on paper why the addition of
> shearDispl increment.

yes! It shouldn't be there. I feel that this error (using shearDisp)
is somehow balancing the bug somewhere else, which causes mysterious
increase of kinetic energy.

Janek Kozicki                               http://janek.kozicki.pl/  |