Sphere - nonSphere interactions never deleted by Law2_ScGeom_CapillaryPhys_Capillarity

Bug #1628273 reported by Jérôme Duriez
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Yade
Fix Released
Undecided
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Bug Description

Hi,

Let say one performs simulation with Law2_ScGeom_CapillaryPhys_Capillarity and Law2_ScGeom_FrictPhys_CundallStrack.neverErase = 1 (in order to keep menisci between separated particles)

In such case, interactions between sphere and non spherical particles (e.g. boundaries) are not deleted by Law2_ScGeom_FrictPhys_CundallStrack when geometrical contact is lost, and are neither handled (deleted because of no meniscus, in particular) by Law2_ScGeom_CapillaryPhys_Capillarity because Law2_ScGeom_CapillaryPhys_Capillarity simply disregards such interaction [*].

And the user ends up with much more interactions than necessary..

I'm filling a Bug report for the record and possible discussion about desired behaviour (sorry I could not provide a MWE !)

Jerome

[*] https://github.com/yade/trunk/blob/master/pkg/dem/Law2_ScGeom_CapillaryPhys_Capillarity.cpp#L98

Revision history for this message
Bruno Chareyre (bruno-chareyre) wrote :

I confirm the bug conceptually (did not reproduce).
Call it memory leak...
Did you realize that incidentaly or have you seen an anomalous growth of interaction number in a simulation?

I wonder how it can be solved without hacks. The notion of multiple physical interactions between two bodies does not fit very well in Yade's picture at the moment.

Bruno

Revision history for this message
Jérôme Duriez (jduriez) wrote :

We realized it thanks to a colleague who was working on interaction data, as exported in a text file. However we did not quantify it precisely yet (and I'm now away from office for a couple of weeks)

Revision history for this message
Jérôme Duriez (jduriez) wrote :

Hi,

Just to give some figures about this bug:
Random examples of triaxial simulations (with 20000 spherical particles and 6 boxes) show here ~ 45% of sphere-wall interactions that are useless at the end of the simulation. Ie ~ 3% of the (real) interactions total number.

I think checking for penetrationDepth < 0 around l.95 of the code [1], before deciding to "continue", would make sense and solve this bug.
OK ?

Do we take the opportunity to replace the shape test [2] with something else ? (what ? if yes)

Jerome

[1] https://github.com/yade/trunk/blob/master/pkg/dem/Law2_ScGeom_CapillaryPhys_Capillarity.cpp#L95
[2] https://github.com/yade/trunk/blob/master/pkg/dem/Law2_ScGeom_CapillaryPhys_Capillarity.cpp#L98

Revision history for this message
Jérôme Duriez (jduriez) wrote :
Changed in yade:
status: New → Fix Released
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