yade-users team mailing list archive

[ceguo <question172345@xxxxxxxxxxxxxxxxxxxxx>]

Question #172345 on Yade changed:
https://answers.launchpad.net/yade/+question/172345

    Status: Answered => Open

ceguo is still having a problem:
Hi Bruno and Chiara,

Here is a small script testing my concern:

from yade import pack

def numInteract():
   print O.interactions.countReal()
   
O.materials.append(FrictMat(young=150e6,poisson=.3,frictionAngle=.4,density=2600))
O.bodies.append(
   [utils.sphere(center=[0,0,0],radius=0.5),
   utils.sphere(center=[1,0,0],radius=0.5),
   utils.sphere(center=[0,1,0],radius=0.5),
   utils.sphere(center=[1,1,0],radius=0.5),
   utils.sphere(center=[0,0,1],radius=0.5),
   utils.sphere(center=[1,0,1],radius=0.5),
   utils.sphere(center=[0,1,1],radius=0.5),
   utils.sphere(center=[1,1,1],radius=0.5)]
)
walls = utils.aabbWalls(thickness=0.1)
O.bodies.append(walls)

O.dt=.5*utils.PWaveTimeStep()
O.engines=[
   ForceResetter(),
   InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()],sweepLength=.025),
   InteractionLoop(
      [Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()],
      [Ip2_FrictMat_FrictMat_FrictPhys()],
      [Law2_ScGeom_FrictPhys_CundallStrack()]
   ),
   NewtonIntegrator(),
   TriaxialCompressionEngine(
      internalCompaction=False,
      sigmaIsoCompaction=100e3,
      max_vel=10
   ),
   PyRunner(command='numInteract()',iterPeriod=10)
]
O.run(100); O.wait()

For this special lattice (regularly aligned eight particles), the number
of particle-particle contacts is 12 and the particle-wall contacts is 8.
So I suppose the coordination number is (12x2+8)/8=4 because we can see
there are exactly 4 contacts for each particle. This means each p-p
contact should be counted twice while each p-w contact once. I'm
confused why the countReal() gives me a value of 9 and
avgNumInteractions() gives me 1.2857 in the test?

I'm sorry I'm new to YADE and may code the script wrongly. Sorry for the
trouble.

Best regards!
Ning

-- 
You received this question notification because you are a member of
yade-users, which is an answer contact for Yade.