yade-users team mailing list archive

[Nejib Hadda <nejib.hadda@xxxxxxxxxxx>]

You're right Chiara, it works for the last version.


I have some other remarks:

1- Yade uses 3 entities to define the contact normal, "normal",
"prevNormal" and "currentNormal". in what does currentNormal differ from
"normal". 
I think also that "prevNormal" is overwritten by "normal" or inversely
when displaying them because there is no differences between the 2
vectors (you can see that in an .xml file for example). so if it is the
case I think we should fix it.

2- While computing the shear increment extracting these componnents
(vel,angVel,contactpoint,Pos1,Pos2,normal, O.dt), computing vectors c1x
and c2x as follow

c1x= ContactPoint-pos1
c2x= ContactPoint-pos2


and using this code (Same one used in ScGeom) :


relVel=vel2+(angVel2).cross(c2x)-(vel1+(angVel1).cross(c1x))		

delta_un=(relVel*normal)*O.dt

shearVel=relVel-(relVel*normal)*normal

ShearInc=shearVel*O.dt


I found that ShearInc computed as above differs from the ShearInc given
by Yade bzr (Last version).
Is there any projection, or operation on coordinate local/global systems
left for me to do so that I find the same value as Yade.

Many thanks !



Le lundi 16 août 2010 à 15:28 +0200, chiara modenese a écrit :
> Hi Nejib,
> 
> sorry for long delay in replying.
>         
>         'shearIncrement' seems not to be an attribute to the object
>         'ScGeom', Do
>         you agree ? is there any alternative to call directly
>         otherwise?
> May I guess what release are you using? In last release shearIncrement
> is accessible via python in read-only mode (see line 54 of ScGeom.hpp)
> which overrides shearInc private attribute of ScGeom (updated into
> precompute function, line 35 of ScGeom.cpp).
> 
> cheers, Chiara
> 
> 
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