← Back to team overview

yade-users team mailing list archive

without contact interaction : eurêka!

 

Hi,

After investigation, I have found the "explosion problem" was linked to 
the fact that Elastic Contact Forces are calculated every time 
BoundingBoxes are interpenetrated.

In fact, with capillary cohesion, interactions can be activated without 
contact. So, to allow this "off contact interaction", I increased the 
size of the BoundingBoxes (1.5*Radius) and, therefore, Elastic Contact 
Forces was calculated even if there was no contact between 2 elements in 
interaction (BoundingBoxes intersected). I don't really know what 
happens at this time (numerical instability...), but, to avoid it, I 
have inserted a new condition in the ElasticContactLaw file, in order to 
apply contact forces only when spheres are in contact (if (D <= 0) 
then... with D =  
(de2->se3.position-de1->se3.position).length()-(currentContactGeometry->radius1+currentContactGeometry->radius2))

It works well for the case of 2 spheres in interaction, but, of course, 
there is a problem when a sphere and a box are concerned (no radius for 
a box!).

Can I define (more properly) this condition of contact for every kind of 
element (It is probably define somewhere, but where?) or do I have to 
create "others" BoundingBoxes, specially for "without contact 
interactions" (Is it possible and suitable?)?

Thanks a lot in advance.

Luc

_______________________________________________
Yade-users mailing list
Yade-users@xxxxxxxxxxxxxxxx
https://lists.berlios.de/mailman/listinfo/yade-users



Follow ups