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\subsection{\texttt{shearcell.py}}\label{code:shearcell}
\begin{verbatim}
#shearcell.py: An annular shear cell simulation using ESyS-Particle
# Author: D. Weatherley
# Date: 24 April 2011
# Organisation: ESSCC, The University of Queensland, Brisbane, AUSTRALIA
# (C) All rights reserved, 2011.
#
#
#import the appropriate ESyS-Particle modules:
from esys.lsm import *
from esys.lsm.util import *
from esys.lsm.geometry import *
from WallLoader import WallLoaderRunnable
from ServoWallLoader import ServoWallLoaderRunnable
#create a simulation container object:
# N.B. there must be at least two sub-divisions
# in the X-direction for periodic boundaries
sim = LsmMpi (numWorkerProcesses=2, mpiDimList=[2,1,1])
sim.initNeighbourSearch (
particleType = "NRotSphere",
gridSpacing = 2.5,
verletDist = 0.5
)
#specify the number of timesteps and timestep increment:
sim.setNumTimeSteps(100000)
sim.setTimeStepSize(0.001)
#enforce two-dimensional computations:
sim.force2dComputations (True)
#specify the spatial domain and direction of periodic boundaries:
domain = BoundingBox ( Vec3 (0,0,0), Vec3 (10,10,0) )
sim.setSpatialDomain (
bBox = domain,
circDimList = [True, False, False]
)
#construct a rectangle of unbonded particles:
packer = RandomBoxPacker (
minRadius = 0.1,
maxRadius = 0.5,
cubicPackRadius = 2.2,
maxInsertFails = 1000,
bBox = BoundingBox(
Vec3(0.0, 0.0,0.0),
Vec3(10.0, 10.0, 0.0)
),
circDimList = [True, False, False],
tolerance = 1.0e-5
)
packer.generate()
particleList = packer.getSimpleSphereCollection()
#tag particles along base and top of rectangle
#then add the particles to the simulation object:
for pp in particleList:
centre = pp.getPosn()
radius = pp.getRadius()
Y = centre[1]
if (Y < 1.0): # particle is near the base (tag=2)
pp.setTag (2)
elif (Y > 9.0): # particle is near the top (tag=3)
pp.setTag (3)
else: # particle is inside the shear cell (tag=1)
pp.setTag (1)
sim.createParticle(pp) # add the particle to the simulation object
#set the density of all particles:
sim.setParticleDensity (
tag = 1,
mask = -1,
Density = 100.0
)
sim.setParticleDensity (
tag = 2,
mask = -1,
Density = 100.0
)
sim.setParticleDensity (
tag = 3,
mask = -1,
Density = 100.0
)
#add driving walls above and below the particle assembly:
sim.createWall (
name = "bottom_wall",
posn = Vec3 (0,0,0),
normal = Vec3 (0,1,0)
)
sim.createWall (
name = "top_wall",
posn = Vec3 (0,10,0),
normal = Vec3 (0,-1,0)
)
#unbonded particle-pairs undergo frictional interactions:
sim.createInteractionGroup (
NRotFrictionPrms (
name = "pp_friction",
normalK = 1000.0,
dynamicMu = 0.6,
shearK = 100.0,
scaling = True
)
)
#particles near the base (tag=2) are bonded to the bottom wall:
sim.createInteractionGroup (
NRotBondedWallPrms (
name = "bwall_bonds",
wallName = "bottom_wall",
normalK = 1000.0,
particleTag = 2
)
)
#particles near the base (tag=3) are bonded to the top wall:
sim.createInteractionGroup (
NRotBondedWallPrms (
name = "twall_bonds",
wallName = "top_wall",
normalK = 1000.0,
particleTag = 3
)
)
#add local damping to avoid accumulating kinetic energy:
sim.createInteractionGroup (
LinDampingPrms (
name = "damping",
viscosity = 1.0,
maxIterations = 100
)
)
#add ServoWallLoaderRunnables to apply constant normal stress:
servo_loader1 = ServoWallLoaderRunnable(
LsmMpi = sim,
interactionName = "twall_bonds",
force = Vec3 (0.0, -1000.0, 0.0),
startTime = 0,
rampTime = 5000
)
sim.addPreTimeStepRunnable (servo_loader1)
wall_loader1 = WallLoaderRunnable(
LsmMpi = sim,
wallName = "bottom_wall",
vPlate = Vec3 (0.125, 0.0, 0.0),
startTime = 30000,
rampTime = 10000
)
sim.addPreTimeStepRunnable (wall_loader1)
#add a FieldSaver to store total kinetic energy:
sim.createFieldSaver (
ParticleScalarFieldSaverPrms(
fieldName="e_kin",
fileName="ekin.dat",
fileFormat="SUM",
beginTimeStep=0,
endTimeStep=100000,
timeStepIncr=1
)
)
#add FieldSavers to store wall forces and positions:
posn_saver = WallVectorFieldSaverPrms(
wallName=["bottom_wall", "top_wall"],
fieldName="Position",
fileName="out_Position.dat",
fileFormat="RAW_SERIES",
beginTimeStep=0,
endTimeStep=100000,
timeStepIncr=1
)
sim.createFieldSaver(posn_saver)
force_saver = WallVectorFieldSaverPrms(
wallName=["bottom_wall", "top_wall"],
fieldName="Force",
fileName="out_Force.dat",
fileFormat="RAW_SERIES",
beginTimeStep=0,
endTimeStep=100000,
timeStepIncr=1
)
sim.createFieldSaver(force_saver)
#add a CheckPointer to store simulation data:
sim.createCheckPointer (
CheckPointPrms (
fileNamePrefix = "snapshot",
beginTimeStep = 0,
endTimeStep = 100000,
timeStepIncr = 5000
)
)
#execute the simulation:
sim.run()
\end{verbatim}
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