How to access the porosity once the compaction is finished in triaxial test?

Asked by Rong Zhao on 2019-09-04

Hello, everyboday!

I am learning a tutorial of Periodic triaxial test (https://yade-dem.org/doc/tutorial-examples.html#periodic-triaxial-test). Here is the code:

from __future__ import print_function
sigmaIso=-1e5

#import matplotlib
#matplotlib.use('Agg')

# generate loose packing
from yade import pack, qt, plot

O.periodic=True
sp=pack.SpherePack()
if 0:
 ## uniform distribution
 sp.makeCloud((0,0,0),(2,2,2),rMean=.1,rRelFuzz=.3,periodic=True)
else:
 ## create packing from clumps
 # configuration of one clump
 c1=pack.SpherePack([((0,0,0),.03333),((.03,0,0),.017),((0,.03,0),.017)])
 # make cloud using the configuration c1 (there could c2, c3, ...; selection between them would be random)
 sp.makeClumpCloud((0,0,0),(2,2,2),[c1],periodic=True,num=500)

# setup periodic boundary, insert the packing
sp.toSimulation()

O.engines=[
 ForceResetter(),
 InsertionSortCollider([Bo1_Sphere_Aabb()]),
 InteractionLoop(
  [Ig2_Sphere_Sphere_ScGeom()],
  [Ip2_FrictMat_FrictMat_FrictPhys()],
  [Law2_ScGeom_FrictPhys_CundallStrack()]
 ),
 PeriTriaxController(label='triax',
  # specify target values and whether they are strains or stresses
  goal=(sigmaIso,sigmaIso,sigmaIso),stressMask=7,
  # type of servo-control
  dynCell=True,maxStrainRate=(10,10,10),
  # wait until the unbalanced force goes below this value
  maxUnbalanced=.1,relStressTol=1e-3,
  # call this function when goal is reached and the packing is stable
  doneHook='compactionFinished()'
 ),
 NewtonIntegrator(damping=.2),
 PyRunner(command='addPlotData()',iterPeriod=100),
]
O.dt=.5*PWaveTimeStep()

def addPlotData():
 plot.addData(unbalanced=unbalancedForce(),i=O.iter,
  sxx=triax.stress[0],syy=triax.stress[1],szz=triax.stress[2],
  exx=triax.strain[0],eyy=triax.strain[1],ezz=triax.strain[2],
  # save all available energy data
  Etot=O.energy.total(),**O.energy
 )

# enable energy tracking in the code
O.trackEnergy=True

# define what to plot
plot.plots={'i':('unbalanced',),'i ':('sxx','syy','szz'),' i':('exx','eyy','ezz'),
 # energy plot
 ' i ':(O.energy.keys,None,'Etot'),
}
# show the plot
plot.plot()

def compactionFinished():
 # set the current cell configuration to be the reference one
 O.cell.trsf=Matrix3.Identity
 # change control type: keep constant confinement in x,y, 20% compression in z
 triax.goal=(sigmaIso,sigmaIso,-.2)
 triax.stressMask=3
 # allow faster deformation along x,y to better maintain stresses
 triax.maxStrainRate=(1.,1.,.1)
 # next time, call triaxFinished instead of compactionFinished
 triax.doneHook='triaxFinished()'
 # do not wait for stabilization before calling triaxFinished
 triax.maxUnbalanced=10

def triaxFinished():
 print('Finished')
 O.pause()

The triaxial consists of 2 stages, one of the stages is isotropic compaction. I want to know whether the porosity is accessed once the compaction is finished. If can, how to access the porosity once the compaction is finished in triaxial test? Or whether I can specify the porosity during the compaction?

Thanks!

Question information

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Last query:
2019-09-04
Last reply:
2019-09-20
Launchpad Janitor (janitor) said : #1

This question was expired because it remained in the 'Open' state without activity for the last 15 days.