[Yade-users] [Question #700475]: interface friction angle
New question #700475 on Yade:
https://answers.launchpad.net/yade/+question/700475
Hi All,
I hope you are doing well.
Recently, I am doing a cone penetration simulation. the following is part of
the code.
##
from yade import ymport
import itertools
from numpy import *
import numpy as np
from yade import pack, plot, export, utils,geom
import math
target=0.12
young=4e8
finalcompFricDegree=19.5
frictDegree = 39.5
# sphere particles material
properties
sphereMat=O.materials.append(CohFrictMat(young=young,poisson=0.3,frictionAngle=radians(finalcompFricDegree),isCohesive=False,alphaKr=0.2,alphaKtw=0,etaRoll=0.5,momentRotationLaw=True,density=2648))
O.bodies.append(ymport.text("rotation-loose-sample-Dr-03.txt",material =
sphereMat))
create the penetrator and
shaft and the cylinder ##
facetMat=O.materials.append(FrictMat(young=young,poisson=0.3,frictionAngle=radians(frictDegree),density=0))
O.materials.append(FrictMat(young=young,poisson=0.3,frictionAngle=0,density=0,label='walls'))
facets =
O.bodies.append(geom.facetCylinder((200e-3,200e-3,300e-3),200e-3,600e-3,wallMask=6,material='walls',segmentsNumber=100))
### coloring
#
cone and shaft geometry parameter
###
x0=0.2;y0=0.2;z0=0.39665
cylinderIDS= O.bodies.append(geom.facetCylinder((x0,y0,0.416651),
radius=0.0125,height=0.15,orientation=Quaternion((1, 0, 0),
0),wallMask=5,segmentsNumber=10, angleRange=None,material=facetMat))
coneIDS= O.bodies.append(geom.facetCone((x0,y0,0.3308255),
radiusTop=0.0125,radiusBottom=0.0,height=0.021651,orientation=Quaternion((1, 0,
0), 0),wallMask=6,segmentsNumber=10, angleRange=None,material=facetMat))
conecheck=O.bodies[-1].id
cone and shaft geometry parameter
###
## set the global engine for the
simulation
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom6D(),Ig2_Facet_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_FrictPhys(),Ip2_CohFrictMat_CohFrictMat_CohFrictPhys()],
[Law2_ScGeom_FrictPhys_CundallStrack(),Law2_ScGeom6D_CohFrictPhys_CohesionMoment(useIncrementalForm=True,always_use_moment_law=True,label='cohesiveLaw')]
),
GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=10,timestepSafetyCoefficient=0.8),
NewtonIntegrator(gravity=(0,0,-9.81),damping=0.0)]
#
#
Generally speaking, the friction angle for particles is 19.5 degrees, while the
friction angle for the penetrator (cylindyer+cone) is 39.5 degrees.
I also set the friction angle for the penetrator as 29.5 degrees. (I just
changed the friction angle for the penetrator, the friction angle for the
particle remains the same. )
when I compare the penetration resistance on the cone for the 29.5-degree case
and the 39.5-degree case. the penetration resistance on the cone is exactly the
same.
###
my question is:
how does Yade choose the interface friction angle between the interactions when
the friction angles were not the same for the particles and the penetrator?
best,
Yong
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Re: [Yade-users] [Question #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 Status: Open => Answered Luc Scholtès proposed the following answer: Hello, I think the rule for the contact laws you are using is: contact friction angle = min (friction angle body1, friction angle body2) In your case, the cone/particle contact friction angle is thus always equal to 19.5 degrees (particle friction angle) if I understood correctly. Unfortunately, I don't know any "python workaround" to change this rule. From my knowledge, only a change in the C++ code would allow you to have a different behavior. To be confirmed... Luc -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 Jan Stránský proposed the following answer: Hello, The combination of material parameters into interaction parameters is usually done inside Ip2. In your code specifically Ip2_FrictMat_FrictMat_FrictPhys, Ip2_CohFrictMat_CohFrictMat_CohFrictPhys. The resulting interaction value is in both cases documented ([1,2]) as given MatchMaker, or minimum value by default. You can also see source code [3,4]. In your case, minimum value is in both cases 19.5 deg. So your results corresponds to the implementation choice. Cheers Jan [1] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.Ip2_FrictMat_FrictMat_FrictPhys.frictAngle [2] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.Ip2_CohFrictMat_CohFrictMat_CohFrictPhys.frictAngle [3] https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/FrictPhys.cpp#L39 [4] https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/CohesiveFrictionalContactLaw.cpp#L289 -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 Status: Answered => Solved ytang confirmed that the question is solved: Hi Luc and Jan, Thank you very much! I'm not trying to change the source code right now. I just want to double-check the reason for this question. best, Yong -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 ytang confirmed that the question is solved: Thanks Jan Stránský, that solved my question. -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
