yade-dev team mailing list archive

["Chiara Modenese" <chiara.modenese@xxxxxxxxx>]

Hi all,

I need your suggestions/explanations. I would have a couple of questions:

1) I see a function defined in ScGeom called updateShear.. Should I include it in my contact law if I use ScGeom? Why is this function defined? If I just need the definition of the shear force (incremental) I suppose I could just use the function updateShear..

2) I would need the Hertz-Mindlin's formulation for the stiffnesses.. Has this one yet been implemented in Yade somewhere? Just to know so I avoid to do that twice..

3) When we apply the contact forces (normal and shear) between particles, these are always acting as repulsive forces according to the sign convention, right? It is just to know, since I see a difference in terms of sign whether we use ScGeom or DemDofGeom..

4) According to the design of Yade, is it possible to interact between two different materials? I ask this because I am including in my contact law some forces that need to act only between spheres and not in the contact box-sphere for instance. One possible solution I see is to define an additional parameter for the (common) maeterial and set it to zero in the case of boxes. I see the same thing happens when we calculate the friction as min(fa,fb) so if we have a box and a sphere we simply take the minimum so we don't have friction. But perhaps it would be nice to define two different materials instead of a parameter for the same material. Could you tell me how to do that?

5) I want to start having forces (say a constant term) between particles before they get in touch (say at a defined distance). Where should I act in the code to do that? Is there defined like a tollerance for the contact interaction?

Thanks a lot.

Chiara