New question #707350 on Yade:
https://answers.launchpad.net/yade/+question/707350
Hello,
I'm compacting a specimen with the PeriTriaxController, then changing
boundaries and switching to TriaxialStressController using the doneHook. I'm
having trouble with pausing/stopping the simulation once the goal stress for
the TriaxialStressController is reached, and am not sure the best way to do
this.
Normally when I am using just the PeriTriaxController, I just chain multiple
doneHooks recursively, so it has not been a problem till now, and I may just be
having problem thinking outside of this paradigm now. I do not see an
equivalent doneHook for the PeriTriaxController.
Any suggestions?
MWE below:
#####################################################################
from __future__ import print_function
from yade import pack, qt, plot, export
sigmaIso = -1e5
# define materials
O.materials.append(CohFrictMat(density=2650,young=9.6e7,
poisson=.28,frictionAngle=0,
isCohesive=False,momentRotationLaw=True,
etaRoll=0,etaTwist=0,label="granr"))
O.materials.append(CohFrictMat(young=1e8, poisson=0.28, frictionAngle=0,
density=0, isCohesive=False, momentRotationLaw=False, etaTwist=0,
label='walls'))
# set periodic boundaries
O.periodic = False
# define log-linear psd
dmin, dmax = 0.07, 0.13
start, end = numpy.log10(dmin), numpy.log10(dmax)
psdSizes = numpy.logspace(start, end, num=25, endpoint=True)
psdCumm = numpy.linspace(0, 1., len(psdSizes))
# make packing
sp = pack.SpherePack()
sp.makeCloud((0, 0, 0), (1, 1, 1), psdSizes=psdSizes, psdCumm=psdCumm,
periodic=True)
sp.toSimulation(material="granr")
O.engines = [
ForceResetter(label='resetter'),
InsertionSortCollider([Bo1_Sphere_Aabb()],
label='collider'),
InteractionLoop([Ig2_Sphere_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_FrictPhys(),
Ip2_CohFrictMat_CohFrictMat_CohFrictPhys()],
[Law2_ScGeom_FrictPhys_CundallStrack(),
Law2_ScGeom6D_CohFrictPhys_CohesionMoment()],
label='interactionLoop'),
GlobalStiffnessTimeStepper(
# use adaptive stiffness-based timestepper
timestepSafetyCoefficient=0.8,
timeStepUpdateInterval=100,
# set to True for domain decomp
parallelMode=False,
label='timeStepper'
),
PeriTriaxController(
label='triax',
dead=False,
# specify target values and whether they are strains or stresses
goal=(sigmaIso, sigmaIso, sigmaIso),
stressMask=7,
# type of servo-control
dynCell=True,
maxStrainRate=(0.01, 0.01, 0.01),
# wait until the unbalanced force goes below this value
maxUnbalanced=1e-5,
relStressTol=1e-5,
# call this function when goal is reached and the packing is stable
doneHook='changeBC()'
),
TriaxialStressController(label='triaxw',dead=True),
NewtonIntegrator(damping=.2),
PyRunner(command='addPlotData()', iterPeriod=100),
]
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],
pmw=triaxw.meanStress,
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', 'pmw'),
' i': ('exx', 'eyy', 'ezz'),
# energy plot
' i ': (O.energy.keys, None, 'Etot'),
}
# show the plot
plot.plot()
def changeBC():
# turn off periodic boundaries
O.periodic=False
# deactivate PeriTriaxController
triax.dead=True
# Update engines for walls
collider.boundDispatcher.functors += [Bo1_Box_Aabb()]
interactionLoop.geomDispatcher.functors +=
[Ig2_Box_Sphere_ScGeom(),Ig2_Wall_Sphere_ScGeom()]
## switch to wall TriaxialStressController
# create and append 4 walls of a cube sized to our mn, mx parameters
mn, mx = yade._utils.aabbExtrema() # corners of the final aperiodic packing
walls = aabbWalls([mn, mx], thickness=0, material='walls')
wallIds = O.bodies.append(walls)
# update wall triax goals, assign aabbWall Ids to triax..
triaxw.internalCompaction=False
triaxw.max_vel=.01
triaxw.stressMask=7
triaxw.goal1=triaxw.goal2=triaxw.goal3=sigmaIso
triaxw.wall_left_id=wallIds[0]
triaxw.wall_right_id=wallIds[1]
triaxw.wall_bottom_id=wallIds[2]
triaxw.wall_top_id=wallIds[3]
triaxw.wall_back_id=wallIds[4]
triaxw.wall_front_id=wallIds[5]
# activate wall triax
triaxw.dead=False
# Stop once reach goal stress (does not work?)
O.run()
while True:
if unbalancedForce() < 1e-5 and abs((sigmaIso-triaxw.meanStress)/sigmaIso <
1e-5):
break
O.pause()
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