yade-users team mailing list archive

[Jan Stránský <question696515@xxxxxxxxxxxxxxxxxxxxx>]

Question #696515 on Yade changed:
https://answers.launchpad.net/yade/+question/696515

Jan Stránský proposed the following answer:
>>how to enlarge the polyhedron?
> For polyhedron-polyhedron,I found that in Ig2_Polyhedra_Polyhedra_PolyhedraGeom[6]the rotation matrix is multiplied by interactionDetectionFactor to enlarge the two polyhedrons.This may be helpful in my case to enlarge between 2 polyhedrons.But for the interaction between sphere and polyhedron，how should I deal with it

It is up to you and your needs :-)
For sphere, I think the only meaningful option is to simply enlarge its radius.
For polyhedrons, there more options:
- simply enlarge the polyhedron vertices from the polyhedron center
- wrap the polyhedron with "equidistant" surface, something like Minkowski sum
- surely other meaningful polyhedron enlargement exist
The proper choice depends on the problem.

>> How to set stiffness of such distant interaction?
> The values of kn and Ks depend on crosssection and reflength. For polyhedron - polyhedron, polyhedron - sphere, is their crosssection calculation still pi * Rmin ^ 2[8]? If so, is the value of radius should multiplied by interactiondetectionfactor?

I agree with Bruno that multiplication of these values by
interactionDetectionFactor does not make much sense (although of course
it can be used).

In general, the Rmin, cross-section and refLength may be used.
Rmin for polyhedron is currently a rough estimation (or even hack), it can be done in a more sophisticated way if needed - e.g. taking into account orientation of the interaction w.r.t polyhedron orientation.

Cheers
Jan

-- 
You received this question notification because your team yade-users is
an answer contact for Yade.