yade-dev team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

Hi Luc,
> 1- CohesiveFrictionalPM seems to work well when it is used in basic 
> simulations (say two elements, sphere/sphere or sphere/box) and 
> without the moment law (the moment law produces the same "explosive 
> behaviour" when used with CohesiveFrictionalContactLaw, so it is 
> probably due to some problems with quaternion computation in Eigen as 
> it worked well with wm3... Unless there was something wrong with wm3...)
Did you check the current trunk compiled with wm3? Reading your mail, I 
still don't know if it is related to eigen or not.

> The first thing I have noticed is that, if the timestep is fixed with 
> O.dt=-0.2*utils.PWaveTimeStep() (see the - before 
> 0.2*utils.PWaveTimeStep()), GlobalStiffnessTimeStepper() does not 
> update the timestep for CohesiveFrictionalPM (it does for 
> CohesiveFrictionalContactLaw), and, the walls just go through the 
> assembly.
I don't see why timestepper behaves differently with different contact 
laws. This is weird.

> The only (!!!!) difference between the two laws is that, one uses the 
> penetration depth as the interacting distance, whereas the other 
> initializes the interacting distance to the penetration depth when an 
> interaction is detected, and I saw this: 
> https://bugs.launchpad.net/yade/+bug/399963. Do you think it could be 
> related?
I don't think so. It would not explain how you got correct results before.

Bruno