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Re: Elastic energy


(sorry, working over vnc caused me to accidentally send before I
finished writing this email - sending again)

chiara modenese said:     (by the date of Fri, 2 Jul 2010 17:41:36 +0100)

> Hi guys,
> I am experiencing again a bit of troubles with total energy conservation.
> For a sphere-sphere impact test everything seems fine. Now I have tried
> another simple example: few spheres with an input initial velocity in a box.
> I attach the script, if you run it you will obtain the plot in the attached
> figure. If there is no friction, then total energy is more or less constant
> as shown in the first part of the plot (not exactly constant due to the way
> we compute velocities, as already discussed in this thread
> http://www.mail-archive.com/yade-users@xxxxxxxxxxxxxxxxxxx/msg01729.html).
> However, as long as I include some friction, both total and kinetic energy
> decreases and no slip occurs since the function plasticDissipation() of
> Law2_ScGeom_FrictPhys_Basic contact law returns 0. I have already checked on
> paper and discussed with Bruno and the code which computes
> plasticDissipation in ScGeom is formally correct.

How about heat? Usually friction increases temperature of those
bodies that are in friction. But in yade we don't have heat, so this
turns into an energy loss.

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

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