# Zero force and torque on clumps

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Hi!

I would like to sum the torque values collected from clump members on an axis of a mixer. My problem is that all the force and torque vectors are zero despite of there are visible collisions between the particles and the mixer.

Here's my code:

import woo, math
from woo import utils
from woo.core import *
from woo.dem import *
from woo import plot
from woo import *
from minieigen import *

# scene:
S=woo.master.scene=woo.core.Scene(fields=[DemField(gravity=(0,-9.81,0))])

n=1
angularvel=2*math.pi*n

#model locations
drumlocation='/home/dem/woo/drum_k.stl'
mixerlocation='/home/dem/woo/mixer_k.stl'

Vmax=.01234
Hdep=(V/.14)+.1

#drum mixer's geometry
S.lab.mixNode=Node(pos=(0,0,0),dem=ClumpData(blocked='xyzXYZ'),ori=Quaternion((0,0,1),math.pi/2.))
global kevero
S.lab.mixNode.dem.angVel=(0,0,angularvel)

#particles
sp=woo.pack.SpherePack()
sp.makeCloud((-.1,.1,-.35),(.1,Hdep,.35),rMean=.005,rRelFuzz=.001,num=300000)
sp.toDem(S,mat=woo.utils.defaultMaterial(),color=.4)

S.dtSafety=1
S.saveTmp()
from woo import qt
v=qt.View()
v.eyePosition=(-0.8,.3,.8);v.upVector=(0,1,0);v.viewDir=(.8,-0.3,-0.7)

# engines:
S.engines=S.dem.minimalEngines(damping=.2)+[PyRunner(5,'printData(S)')]

def printData(S):
print ClumpData.forceTorqueFromMembers(mixerelement)	

Any suggestions?

Thanks,

D

commented Feb 14 by (46,530 points)

Hi, strange. I will prepare some minimal mixer simulation and will let you know. Please be patient, a few days. Or you could send me complete simulation source so that I can reproduce easily, perhaps by e-mail (see my contact at woodem.eu). Cheers, vaclav

answered Feb 15 by (46,530 points)
selected Feb 15