New question #482040 on Yade:
https://answers.launchpad.net/yade/+question/482040
Hi
I am trying to understand basic behaviour of unsaturated soils. For my
simulations i am using triaxial stress controller. But for my analysis i am
first generating a packing with zero suction at a desired porosity and then i
am using the saved packing and introducing a suction value for my further
studies. I just want to know whether my approach is right or not.
Here are my scripts:
########################
#script 1
########################
# generate loose packing
from yade import pack, qt, plot
#some parameters:
young_modulus=5e6
friction = 0.6
angle = atan(friction)
targetPorosity=0.42
local_damping = 0.01
stabilityThreshold=0.01
viscous_normal = 0.021
viscous_shear = 0.8*viscous_normal
mn = Vector3(0,0,0)
mx = Vector3(.05,.05,.05)
#key ='_triax_base_',
#creating a material (FrictMat):
O.materials.append(FrictMat(young=young_modulus,poisson=0.5,frictionAngle=angle,density=2600,label='spheres'))
#SphereMat=O.materials[id_SphereMat]
O.materials.append(FrictMat(young=young_modulus,poisson=0.5,frictionAngle=0,density=0,label='walls'))
#generate boundary:
walls=aabbWalls([mn,mx],thickness=0,material='walls')
wallIds=O.bodies.append(walls)
#generate particles:
sp=pack.SpherePack()
sp.makeCloud(mn,mx,rMean=.0012, seed=1)
O.bodies.append([sphere(c,r,material='spheres') for c,r in sp])
triax=TriaxialStressController(thickness = 0,
stressMask = 7,
internalCompaction=False, # If true the confining pressure is
generated by growing particles
#goal1=-100,
#goal2=-100,
#goal3=-100,
max_vel=0.001,
)
#define engines:
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_CapillaryPhys()], #for linear model only
[Law2_ScGeom_FrictPhys_CundallStrack(neverErase=True)] #for linear
model only
),
Law2_ScGeom_CapillaryPhys_Capillarity(capillaryPressure=0),#for linear model
only
GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8),
triax,
TriaxialStateRecorder(iterPeriod=100,file='Target_porosity.txt'),
NewtonIntegrator(damping=local_damping),
#PyRunner(command='addPlotData()',iterPeriod=100)
]
#apply isotropic compression
triax.goal1=triax.goal2=triax.goal3=-10
while 1:
O.run(1000, True)
##the global unbalanced force on dynamic bodies, thus excluding boundaries,
which are not at equilibrium
unb=unbalancedForce()
print 'unbalanced force:',unb,' mean stress: ',triax.meanStress
if unb<stabilityThreshold and abs(-10-triax.meanStress)/10<0.01:
break
print 'out'
import sys #this is only for the flush() below
while triax.porosity>targetPorosity:
## we decrease friction value and apply it to all the bodies and contacts
friction = 0.95*friction
setContactFriction(friction)
print "\r Friction: ",friction," porosity:",triax.porosity,
sys.stdout.flush()
## while we run steps, triax will tend to grow particles as the packing
## keeps shrinking as a consequence of decreasing friction. Consequently
## porosity will decrease
O.run(500,1)
setContactFriction(0.5)
print '\r Friction_angle:', friction
O.save('compactedState_packing.yade.gz')
O.pause()
##################
#Script 2
##################
from yade import plot
import numpy
O.load('compactedState_packing.yade.gz')
triax_iso=TriaxialStressController(thickness = 0,
stressMask = 7,
internalCompaction=False, # If true the confining pressure is
generated by growing particles
max_vel=0.00001,
)
#define engines:
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_CapillaryPhys()], #for linear model only
[Law2_ScGeom_FrictPhys_CundallStrack(neverErase=True)] #for linear
model only
),
Law2_ScGeom_CapillaryPhys_Capillarity(capillaryPressure=10),#for linear model
only
GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8),
triax_iso,
TriaxialStateRecorder(iterPeriod=100,file='Isotropic_10_200.txt'),
NewtonIntegrator(damping=0.01),
PyRunner(command='addPlotData()',iterPeriod=400)
]
#apply isotropic compression
triax_iso.goal1=triax_iso.goal2=triax_iso.goal3=-200
def addPlotData():
plot.addData(
i=O.iter,
s11=-triax_iso.stress(triax_iso.wall_right_id)[0],s22=-triax_iso.stress(triax_iso.wall_top_id)[1],s33=-triax_iso.stress(triax_iso.wall_front_id)[2],
e11=-triax_iso.strain[0],e22=-triax_iso.strain[1],e33=-triax_iso.strain[2],
poro=utils.porosity(), stress=-triax_iso.meanStress,
)
#set time step and run simulation:
O.dt=0.5*PWaveTimeStep()
plot.plots={'i ':('s11','s22','s33'),' i':('e11','e22','e33'),
'stress':('poro')}
#show the plot
plot.plot()
#save the plot
#plot.saveDataTxt('Porosity_1.txt',vars=('i','s11','s22','s33','e11','e22','e33','poro','stress'))
from yade import qt
qt.View()
print('Press PLAY button')
Thanks
Amiya
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