Interaction between Polyhedra and Facets

Hello,

The "IGeom" of the appearing Polyhedra - Facet(Box) interaction is of PolyhedraGeom type (see Ig2_Facet_Polyhedra_PolyhedraGeom() in your script)

However, for what concerns the "IPhys" of this interaction, execution of Ip2_FrictMat_PolyhedraMat_FrictPhys 's job triggers some execution of Ip2_FrictMat_FrictMat_FrictPhys [1].

This Ip2_FrictMat_FrictMat_FrictPhys::go is designed for interaction with "IGeom" of "GenericSpheresContact" (or derived) types [2]. And the PolyhedraGeom type is not one of those [3]

To be short: Yade is currently not designed to deal with the interaction you want.... Discussing code improvements or workarounds will require the answer of other users familiar with this code...

Jerome

[1] https://github.com/yade/trunk/blob/master/pkg/dem/Polyhedra.cpp#L414
[2] https://github.com/yade/trunk/blob/master/pkg/dem/FrictPhys.cpp#L17
[3] https://yade-dem.org/doc/yade.wrapper.html#igeom

PS: thank you for complying the in the air "MWE" question fashion !

Hi José,

O.engines=[
> ...

   InteractionLoop(
> [Ig2_Facet_Polyhedra_PolyhedraGeom()],
> [Ip2_FrictMat_PolyhedraMat_FrictPhys()],
> [Law2_ScGeom_FrictPhys_CundallStrack()],
> ),
> ...
> ]

The problem (as the error says) is here:
Ig2_Facet_Polyhrda_PolyhedraGeom -> PolyhedraGeom instance
Ip2_FrictMAt_PolyhedraMat_FrictPhys -> FrictPhyd
Law2_ScGeom_FrictPhys_CundallStrack -> combines ScGeom and FrictPhys, but
you have PolyhedraGeom and FrictPhys from previous pieces of code..

try Law2_ScGeom_FrictPhys_CundallStrack [1] instead

cheers
Jan

[1]
https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.Law2_ScGeom_FrictPhys_CundallStrack

2015-07-21 22:36 GMT+02:00 Jérôme Duriez <
<email address hidden>>:

> Question #269513 on Yade changed:
> https://answers.launchpad.net/yade/+question/269513
>
> Status: Open => Answered
>
> Jérôme Duriez proposed the following answer:
> Hello,
>
> The "IGeom" of the appearing Polyhedra - Facet(Box) interaction is of
> PolyhedraGeom type (see Ig2_Facet_Polyhedra_PolyhedraGeom() in your
> script)
>
> However, for what concerns the "IPhys" of this interaction, execution of
> Ip2_FrictMat_PolyhedraMat_FrictPhys 's job triggers some execution of
> Ip2_FrictMat_FrictMat_FrictPhys [1].
>
> This Ip2_FrictMat_FrictMat_FrictPhys::go is designed for interaction
> with "IGeom" of "GenericSpheresContact" (or derived) types [2]. And the
> PolyhedraGeom type is not one of those [3]
>
>
> To be short: Yade is currently not designed to deal with the interaction
> you want.... Discussing code improvements or workarounds will require the
> answer of other users familiar with this code...
>
> Jerome
>
> [1] https://github.com/yade/trunk/blob/master/pkg/dem/Polyhedra.cpp#L414
> [2] https://github.com/yade/trunk/blob/master/pkg/dem/FrictPhys.cpp#L17
> [3] https://yade-dem.org/doc/yade.wrapper.html#igeom
>
>
> PS: thank you for complying the in the air "MWE" question fashion !
>
> --
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Thanks to both, It works Jan, but the PolyhedraPhys_Volumetric can include a frictionAngle?

Thanks Jan Stránský, that solved my question.

Hi José,

friction angle is an attribute of PolyhedraMat [1]. However, I don't know
the implementation, but you can test it on simple 2 particle simulation :-)

cheers
Jan

[1] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.PolyhedraMat

2015-07-22 20:31 GMT+02:00 José Mercado <
<email address hidden>>:

> Question #269513 on Yade changed:
> https://answers.launchpad.net/yade/+question/269513
>
> Status: Answered => Solved
>
> José Mercado confirmed that the question is solved:
> Thanks Jan Stránský, that solved my question.
>
> --
> You received this question notification because you are a member of
> yade-users, which is an answer contact for Yade.
>
> _______________________________________________
> Mailing list: https://launchpad.net/~yade-users
> Post to : <email address hidden>
> Unsubscribe : https://launchpad.net/~yade-users
> More help : https://help.launchpad.net/ListHelp
>

Thanks for the answer Jan.

Hi Jose,

I am so interested in your work.

However, I tried to run your scripts, it still cannot work normally.

Ther scripts I ran is as follows:

##################################
from yade import polyhedra_utils
import random

polyMat = PolyhedraMat(density=3000,young=1e10,poisson=.5,frictionAngle=atan(0.8))
frictMat = FrictMat(density=8000,young=1e9,poisson=.5,frictionAngle=atan(0.8))

O.materials.append((polyMat,frictMat))

t=polyhedra_utils.polyhedra(polyMat,(2,2,2),v=[])
t.state.pos = (0,0,5)
O.bodies.append(t)

O.bodies.append(geom.facetBox((0,0,-2),(5,5,10)))

O.engines=[
   ForceResetter(),
   InsertionSortCollider([Bo1_Polyhedra_Aabb(),Bo1_Facet_Aabb()],verletDist=0.5),
   InteractionLoop(
      [Ig2_Facet_Polyhedra_PolyhedraGeom()], # [1]
      [Ip2_PolyhedraMat_PolyhedraMat_PolyhedraPhys()], # [2]
      [Law2_PolyhedraGeom_PolyhedraPhys_Volumetric()], # [3]
),
    NewtonIntegrator(damping=0.5,gravity=(0,0,-9.81))
]

O.dt=0.025*polyhedra_utils.PWaveTimeStep()

from yade import qt
v=qt.View()
v.axes=True

Hello,
there is the same problem as Jose had. If you delete the FrictMat, i.e.
###
...
polyMat = PolyhedraMat(density=3000,young=1e10,poisson=.5,frictionAngle=atan(0.8))
O.materials.append(polyMat)
...
###
it works
cheers
Jan