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# gravity deposition, continuing with oedometric test after stabilization
# shows also how to run parametric studies with yade-batch
# The components of the batch are:
# 1. table with parameters, one set of parameters per line (ccc.table)
# 2. readParamsFromTable which reads respective line from the parameter file
# 3. the simulation muse be run using yade-batch, not yade
#
# $ yade-batch --job-threads=1 03-oedometric-test.table 03-oedometric-test.py
#
# load parameters from file if run in batch
# default values are used if not run from batch
readParamsFromTable(rMean=.05, rRelFuzz=.3, maxLoad=1e6, minLoad=1e4)
# make rMean, rRelFuzz, maxLoad accessible directly as variables later
from yade.params.table import *
# create box with free top, and ceate loose packing inside the box
from yade import pack, plot
O.bodies.append(geom.facetBox((.5, .5, .5), (.5, .5, .5), wallMask=31))
sp = pack.SpherePack()
sp.makeCloud((0, 0, 0), (1, 1, 1), rMean=rMean, rRelFuzz=rRelFuzz)
sp.toSimulation()
O.engines = [
ForceResetter(),
# sphere, facet, wall
InsertionSortCollider([Bo1_Sphere_Aabb(), Bo1_Facet_Aabb(), Bo1_Wall_Aabb()]),
InteractionLoop(
# the loading plate is a wall, we need to handle sphere+sphere, sphere+facet, sphere+wall
[Ig2_Sphere_Sphere_ScGeom(), Ig2_Facet_Sphere_ScGeom(), Ig2_Wall_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_FrictPhys()],
[Law2_ScGeom_FrictPhys_CundallStrack()]
),
NewtonIntegrator(gravity=(0, 0, -9.81), damping=0.5),
# the label creates an automatic variable referring to this engine
# we use it below to change its attributes from the functions called
PyRunner(command='checkUnbalanced()', realPeriod=2, label='checker'),
]
O.dt = .5 * PWaveTimeStep()
# the following checkUnbalanced, unloadPlate and stopUnloading functions are all called by the 'checker'
# (the last engine) one after another; this sequence defines progression of different stages of the
# simulation, as each of the functions, when the condition is satisfied, updates 'checker' to call
# the next function when it is run from within the simulation next time
# check whether the gravity deposition has already finished
# if so, add wall on the top of the packing and start the oedometric test
def checkUnbalanced():
# at the very start, unbalanced force can be low as there is only few contacts, but it does not mean the packing is stable
if O.iter < 5000:
return
# the rest will be run only if unbalanced is < .1 (stabilized packing)
if unbalancedForce() > .1:
return
# add plate at the position on the top of the packing
# the maximum finds the z-coordinate of the top of the topmost particle
O.bodies.append(wall(max([b.state.pos[2] + b.shape.radius for b in O.bodies if isinstance(b.shape, Sphere)]), axis=2, sense=-1))
global plate # without this line, the plate variable would only exist inside this function
plate = O.bodies[-1] # the last particles is the plate
# Wall objects are "fixed" by default, i.e. not subject to forces
# prescribing a velocity will therefore make it move at constant velocity (downwards)
plate.state.vel = (0, 0, -.1)
# start plotting the data now, it was not interesting before
O.engines = O.engines + [PyRunner(command='addPlotData()', iterPeriod=200)]
# next time, do not call this function anymore, but the next one (unloadPlate) instead
checker.command = 'unloadPlate()'
def unloadPlate():
# if the force on plate exceeds maximum load, start unloading
if abs(O.forces.f(plate.id)[2]) > maxLoad:
plate.state.vel *= -1
# next time, do not call this function anymore, but the next one (stopUnloading) instead
checker.command = 'stopUnloading()'
def stopUnloading():
if abs(O.forces.f(plate.id)[2]) < minLoad:
# O.tags can be used to retrieve unique identifiers of the simulation
# if running in batch, subsequent simulation would overwrite each other's output files otherwise
# d (or description) is simulation description (composed of parameter values)
# while the id is composed of time and process number
plot.saveDataTxt(O.tags['d.id'] + '.txt')
O.pause()
def addPlotData():
if not isinstance(O.bodies[-1].shape, Wall):
plot.addData()
return
Fz = O.forces.f(plate.id)[2]
plot.addData(Fz=Fz, w=plate.state.pos[2] - plate.state.refPos[2], unbalanced=unbalancedForce(), i=O.iter)
# besides unbalanced force evolution, also plot the displacement-force diagram
plot.plots = {'i': ('unbalanced',), 'w': ('Fz',)}
plot.plot()
O.run()
# when running with yade-batch, the script must not finish until the simulation is done fully
# this command will wait for that (has no influence in the non-batch mode)
waitIfBatch()
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