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[Sarath Chandra Reddy <question697095@xxxxxxxxxxxxxxxxxxxxx>]

Question #697095 on Yade changed:
https://answers.launchpad.net/yade/+question/697095

    Status: Answered => Open

Sarath Chandra Reddy is still having a problem:
Hi Jan,
Thanks for the reply. 

> Please avoid in the future to post several questions in one Launchpad
question. - Sure

I am a new user to YADE. Based on your suggestions, I tried the
following code for simple CD triaxial test stage but I think I have
missed something in my code as the engine is not working after particle
generation. Can you please let me know if I missed some thing.

from yade import pack
from numpy import arange
import itertools
import random
import yade.plot
## Extra things are also imported for future use
## corners of the initial packing
mn,mx=Vector3(0,0,0),Vector3(0.04,0.04,0.04)
finalFricDegree = 30
rate=0.02
stabilityThreshold=0.01
damp = 0.2
## create material #0, which will be used as default

id_Mat=O.materials.append(FrictMat(young=7e7,poisson=.4,frictionAngle=radians(5.8),density=2650,label='spheres'))
O.materials.append(FrictMat(young=7e6,poisson=.4,frictionAngle=0,density=3000,label='walls'))
Mat=O.materials[id_Mat]

## create walls around the packing
walls=aabbWalls([mn,mx],thickness=0,material='walls')
wallIds=O.bodies.append(walls)

#create assembly of spheres:
sp=pack.SpherePack()
sp.makeCloud(mn,mx,num=15000,rMean=.0005,rRelFuzz=0.0,periodic=False),

O.bodies.append([sphere(center,rad,material='spheres') for center,rad in sp])
print(len(sp),' particles generated.')
#sp.toSimulation()

from yade import qt
qt.Controller()
qt.View()

## hope that we got the ids right?!

triax = TriaxialStressController(
maxMultiplier=1.+2e4/young, # spheres growing factor (fast growth)
finalMaxMultiplier=1.+2e3/young, # spheres growing factor (slow growth)
 wall_bottom_id=wallIds[2],
 wall_top_id=wallIds[3],
 wall_left_id=wallIds[0],
 wall_right_id=wallIds[1],
 wall_back_id=wallIds[4],
 wall_front_id=wallIds[5],
 internalCompaction=False,

 thickness = 0,
 stressMask =7,
 max_vel=1,
)

newton=NewtonIntegrator(damping=damp)

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()]
 ),
 GlobalStiffnessTimeStepper(timestepSafetyCoefficient=0.2),
 triax,
 TriaxialStateRecorder(iterPeriod=100,file='WallStresses'+table.key),
 # you can add TriaxialStateRecorder and such here…
 newton,
        
]
Gl1_Sphere.stripes=0
if nRead==0: yade.qt.Controller(), yade.qt.View()

##############################
###   Confining Stage   ###
##############################

triax.goal1=triax.goal2=triax.goal3=100000
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(100000-triax.meanStress)/100000<0.001:
     break

O.save('confinedState'+key+'.yade.gz')
print ("###      Isotropic state saved      ###")

##############################
###   DEVIATORIC LOADING   ###
##############################

##We move to deviatoric loading, let us turn internal compaction off to keep particles sizes constant
triax.internalCompaction=False

## Change contact friction (remember that decreasing it would generate instantaneous instabilities)
setContactFriction(radians(finalFricDegree))

##set stress control on x and z, we will impose strain rate on y
triax.stressMask = 5
##now goal2 is the target strain rate
triax.goal2=-rate
## we define the lateral stresses during the test, here the same 10kPa as for the initial confinement.
triax.goal1=100000
triax.goal3=100000

##we can change damping here. What is the effect in your opinion?
newton.damping=0.1

##Save temporary state in live memory. This state will be reloaded from the interface with the "reload" button.
O.saveTmp()
O.run(100000,True)

Thanking you in advance,
Sarath

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