yade-users team mailing list archive
Mailing list archive
Re: The convergence criterion in YADE
so CC is used to determine whether the calculations can be stopped,
because nothing is moving, right?
Yes/No, see below.
CC is just an heuristic approach to evaluate stability. Momentum could
equally well be included in the formulae, but in the most common
definition of CC they are not.
so you mean that we need to calculate a sum of all Forces in
PhysicalActionContainer, and also calculate their mean value.
And momentum is ignored?
Not always! For instance, if you want to simulate a quasi-static triaxial test, you assign a final value of axial strain, not CC. But you can record CC during the test to check that it is always "very small", i.e. not far from static conditions. However I don't know exactly what "very small" means ;). In fact, I am not very confident when someone try to proove quasistaticity based on CC only...
But then - if it determines that the simulation is
finished=stable=all_forces_are_in_equilibrum - then I guess that we want
to simulation to be automatically stopped :).
So, perhaps we need a standalone engine to record CC AND a simulation stopper based on this engine.
Maître de conférence
Institut National Polytechnique de Grenoble
Tél : 04.56.52.86.21
bureau I 08
Laboratoire 3S (Soils Solids Structures)
BP 53 - 38041, Grenoble cedex 9 - France