yade-users team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

> so CC is used to determine whether the calculations can be stopped,
> because nothing is moving, right?
>
>  
Yes/No, see below.

> 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?
>
>  
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.

> 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 :).
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... 

So, perhaps we need a standalone engine to record CC AND a simulation stopper based on this engine.

Bruno
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Chareyre Bruno
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