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[jamespaul <question678348@xxxxxxxxxxxxxxxxxxxxx>]

Question #678348 on Yade changed:
https://answers.launchpad.net/yade/+question/678348

jamespaul posted a new comment:
Hi Bruno,

Please run my program. It takes about two minutes.Thank you so much!

1.I have defined a material called 'sphere'. First, it does isotropic
compression. The measured data are very correct.

2.Then,using 'doneHook', it does one-dimensional compression. So before
compression, I applied the 'changeMaterial' function to change the
friction.Am I correct in changing the material?

3.The strange thing is that in one-dimensional compression, the pressure
becomes zero.If I use the default material, everything is fine, that is,
the pressure increases slowly with one-dimensional compression.I used my
own material. Why is this anti-science?

James

##########################
# encoding: utf-8
from yade import pack, qt, plot

sigmaIso=-25000

O.periodic=True

sphere=O.materials.append(FrictMat(young=64e9,poisson=0.12,density=2650,frictionAngle=0.231,label='sphere'))
#s=O.materials.append(FrictMat(young=64e9,poisson=0.12,density=2650,frictionAngle=0.24))

multiple=.01
length=2

psdSizes=[0.15*multiple,.18*multiple,.2*multiple,.21*multiple,.25*multiple,.27*multiple,.30*multiple,.31*multiple,.34*multiple,.38*multiple]
psdCumm=[0.025,0.11,0.27,0.45,0.73,0.88,0.95,0.98,0.99,1]

sp=pack.SpherePack()
sp.makeCloud((0,0,0),(length*multiple,length*multiple,length*multiple),psdSizes=psdSizes,psdCumm=psdCumm,distributeMass=True,periodic=True)
n=sp.toSimulation()

O.engines=[
 ForceResetter(),
 InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
 InteractionLoop(
  [Ig2_Sphere_Sphere_ScGeom()],
  [Ip2_FrictMat_FrictMat_FrictPhys()],
  [Law2_ScGeom_FrictPhys_CundallStrack()]
 ),
 PeriTriaxController(label='triax',
  goal=(sigmaIso,sigmaIso,sigmaIso),stressMask=7,
  dynCell=True,maxStrainRate=(5,5,5),
  maxUnbalanced=.1,relStressTol=1e-3,
  doneHook='compactionFinished()'
 ),
 NewtonIntegrator(damping=.1),
 PyRunner(command='addPlotData1()',iterPeriod=10000),
]
O.dt=.5*PWaveTimeStep()
qt.Controller()

def addPlotData1():
 plot.addData(sxx=-triax.stress[0],syy=-triax.stress[1],szz=-triax.stress[2],
         exx=-triax.strain[0],eyy=-triax.strain[1],ezz=-triax.strain[2],
  unbalanced=unbalancedForce(),i=O.iter,
  )
 print('szz=',-triax.stress[2],'ezz=',-triax.strain[2],'Force=',unbalancedForce())

plot.plots={'i':('unbalanced',),'i ':('sxx','syy','szz'),' i':('exx','eyy','ezz')}
plot.plot()

def changeMaterial():
    s=O.materials.append(FrictMat(young=64e9,poisson=0.12,density=2650,frictionAngle=0.24))
 for i in n:
         O.bodies[i].material.frictionAngle=0.24
         #O.bodies[i].material = O.materials[s]

def compactionFinished():
    print('Now, one-dimensional compression!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!')
 O.engines += [PyRunner(command='changeMaterial()',initRun=1,nDo=1)];
    O.cell.trsf=Matrix3.Identity
   triax.goal=(-1000000,-1000000,-1000000)
 triax.dynCell=True
 triax.relStressTol=1e-3
 triax.stressMask=7
 triax.maxStrainRate=(0,0,0.00001)
 triax.doneHook='triaxFinished()'
 triax.maxUnbalanced=0.1

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

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