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[Swapnil <question658938@xxxxxxxxxxxxxxxxxxxxx>]

Question #658938 on Yade changed:
https://answers.launchpad.net/yade/+question/658938

Swapnil posted a new comment:
Jerome,
I have been thinking of first trying the Full Saturation condition of granular media here.

I referred to the Oedometer.py script utilisong the particle-fluid
coupling and building up my case from the scenario depicted there.

the following is the script:

from yade import pack

num_spheres=1000# number of spheres
young=1e6
compFricDegree = 3 # initial contact friction during the confining phase
finalFricDegree = 30 # contact friction during the deviatoric loading
mn,mx=Vector3(0,0,0),Vector3(1,1,1) # corners of the initial packing

O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=radians(compFricDegree),density=2600,label='spheres'))
O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=0,density=0,label='walls'))
walls=aabbWalls([mn,mx],thickness=0,material='walls')
wallIds=O.bodies.append(walls)

sp=pack.SpherePack()
sp.makeCloud(mn,mx,-1,0.3333,num_spheres,False, 0.95,seed=1) #"seed" make the "random" generation always the same
sp.toSimulation(material='spheres')

triax=TriaxialStressController(
	maxMultiplier=1.+2e4/young, # spheres growing factor (fast growth)
	finalMaxMultiplier=1.+2e3/young, # spheres growing factor (slow growth)
	thickness = 0,
	stressMask = 7,    
	max_vel = 0.005,
	internalCompaction=True, # If true the confining pressure is generated by growing particles
)

newton=NewtonIntegrator(damping=0.2)

O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]),
	InteractionLoop(
		[Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()],
		[Ip2_FrictMat_FrictMat_FrictPhys()],
		[Law2_ScGeom_FrictPhys_CundallStrack()],label="iloop"
	),
	FlowEngine(dead=1,label="flow"),#introduced as a dead engine for the moment, see 2nd section
	GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8),
	triax,
	newton
]

#loading only along Z-direction (1D consolidation test)
triax.goal1=triax.goal2=0
triax.goal3=-10000                               --->  Is this correct?


# full saturation condition

#B. Activate flow engine and set boundary conditions in order to get permeability
flow.dead=0
flow.defTolerance=0.3
flow.meshUpdateInterval=200
flow.useSolver=3             -----?????
flow.permeabilityFactor=1
flow.viscosity=1
flow.bndCondIsPressure=[0,0,1,1,0,0]  ---??? format meaning
flow.bndCondValue=[0,0,1,0,0,0]
flow.boundaryUseMaxMin=[0,0,0,0,0,0]
O.dt=0.1e-3
O.dynDt=False

O.run(1,1)
Qin = flow.getBoundaryFlux(2)  ---??? Number denote which boundary
Qout = flow.getBoundaryFlux(3)
permeability = abs(Qin)/1.e-4 #size is one, we compute K=V/∇H
print "Qin=",Qin," Qout=",Qout," permeability=",permeability

#C. now the oedometer test, drained at the top, impermeable at the bottom plate
flow.bndCondIsPressure=[0,0,0,1,0,0]
flow.bndCondValue=[0,0,0,0,0,0]
newton.damping=0


I have gone through the documentation but there are not enough examples to catch the theme right.

My current doubts with this script are:

1)  How to apply stress only in Z-direction. StressMask needs to hold
what value?   2 or 3 ?

2) I did not understand:  flow.useSolver=3.

3) In  flow.bndCondIsPressure=[0,0,1,1,0,0],
flow.bndCondValue=[0,0,1,0,0,0], flow.boundaryUseMaxMin=[0,0,0,0,0,0],
how to interpret the sequence 0,0,1,1,,....   Could you give a couple of
examples to illustrate.

4) Qin = flow.getBoundaryFlux(2)  ---??? Number denote which boundary
Qout = flow.getBoundaryFlux(3)

for example if we are testing 1D consolidation along Z .axis ( as in my
case) what should I use?

5) Is it not important to provide the density of the fluid we are using.
for example water ..

5) I want to record the change in thickness of sample along the
Z-direction. How do I accomplish that. Do I have to use strain 'ezz' or
is there another direct way?

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