yade-dev team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

Dne 19.3.2009 16:55, Kien Dang, Mr napsal(a):
> Hi,
> According to my understanding,  the shrink factor in the paper is used to avoid the sphere interact with more than one facet, it is; however, not effective and it may cause unstability if shrink factor is too large and determine shrink factor suitable for each simulation is somehow unrealistic. In my opinion, we can remember the number of coincided contact points (in IF2IS4SC) for each sphere, we can check the conincidence by some criterion (contactpoint-contactpoint).Length() smaller than some value (can be tol*sphere radius) and then in the constitutive law the force at the contact will be divided by that number. By that way we can avoid complicated algorithms.
>    
That would be much more complicated actually, since the functors 
shouldn't access interaction containers. The topology information is 
constant throughout the simulation and it makes not much sense to 
determine it at every step. It would essentially add another collider to 
the loop, which would take quite some time.

The shrinkFactor doesn't avoid multiple contacts, since there can always 
be 1 sphere between both facets interacting with both edges.

Vaclav