yade-dev team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

> I'm not sure I understand completely.
> First reaction :
> Why not change "goal" with time, in comp=M*goal? It would give a strain 
> rate.
Goal is user-defined and shouldn't change. It describes, well, the goal
state.

> Second :
> It could be simpler to prescribe strainrates/stresses.
Could be right. Not sure if you woudn't want, in some special cases,
prescribe strain rather than strain rate, though.

Currently, as soon as you reach all the goal components (strains or
stresses) and the packing is stable etc, doneHook is called. With
strainRate, that wouldn't work as well. There must be some 4th condition
regulate rate? Is it meaningful? I am a little at loss, since I have
only few cases I can imagine, but I want to make it quite generic.

> Another point : concerning the displacement field. I think we move 
> particles on the edge first currently (right?), a matrix could be used 
> to move all particles with respect to the deformation of the period (I'm 
> sure you remember discussions about this). Feel free to list precisely 
> what is needed for this, I can try and help coding it.
It is just the cell size that changes, but it really means that (for
compression) particles on the right get closer to the particles on the
left. I was thinking about this linear displacement, but then I wasn't
sure if one should prescribe velocity (and perhaps get adversary inertia
effects later) or just change position and ignore inertia...