yade-users team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

> BTW if someone is willing to write down how is the incremental form
> derived (i.e. the geometrical reasoning behind it), on a piece of paper
> and scan in, I will add it to sphinx documentation of respective classes
> in a proper form. It is a shame that such fundamental algorithm is not
> properly documented. 
>
>   
I could do that. What is to be explained according to you?
Only two things come to mind :

1) Small rotations can be approximated by cross-products, like in 
continuum mechanics in small strain. This is not related with the 
incremental formulation actually. Cross products could be replaced by 
quaternions without any change in the incremental part.

2) The explanation of the incremental part fit in : "if f_s=ks*u_s, then 
df_s = ks*du_s".

Bruno
> Not that the other ones are much better: NewtonIntegrator etc etc will
> need this at one point as well.
>
>   
True, but it would be a bit a waste of time to type everything as if 
there were no books explaining all that already.
The best book I know is actually PFC "theoretical background" chapter, 
too bad it is not public. :(

Anybody knows an alternate reference summarizing the classical 
algorithms of DEM?

Bruno