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[Yuxuan <question691828@xxxxxxxxxxxxxxxxxxxxx>]

New question #691828 on Yade:
https://answers.launchpad.net/yade/+question/691828

Hello Yade programmers and users,
I encountered a problem in my recent simulation script which have been troubling me, and it’d be much appreciated if I can get some advices.

Here are the steps I’m trying to accomplish:
1.	Make a loose pack of particles following defined PSD.
2.	Use compression engine to generate a denser pack.
3.	At defined iteration #, turn off compression engine. 
4.	Filter pack with pack.filterpack into desired shape.
5.	Continue with further steps (gravity deposition, geometry rotation, etc).

My question came with step 3. While using “triaxialStressController.dead=True” to turn off the compression engine, I kept getting the following error: 
---------------------------------------------------
---> 97  controller.dead=True,
ArgumentError: Python argument types in
    None.None(TriaxialStressController, tuple)
did not match C++ signature:
    None(Engine {lvalue}, bool)
---------------------------------------------------
Here is my script using yade 2018.02b:

#!/usr/bin/python
# -*- coding: utf-8 -*-

from __future__ import print_function
import matplotlib; matplotlib.rc('axes',grid=True)
import pylab
from yade import pack, plot, qt
from yade import export

### DEFINING VARIABLES AND MATERIALS ###

#geometry definition
Ri,Rs,Ro=6.5,8.5,10.5
H=3.5
p=H/2
k=0.01 
Hs=H*k 
hs=Hs/2 
Rx=2*Ro
Hx=2*H

c1=geom.facetCylinder(center=(0,0,p),radius=Ro, height=H, segmentsNumber=20, wallMask=6) 
c2=geom.facetCylinder(center=(0,0,hs),radius=Rs, height=Hs, segmentsNumber=20, wallMask=7)
c3=geom.facetCylinder(center=(0,0,p),radius=Ri, height=H, segmentsNumber=20, wallMask=7)


nRead=readParamsFromTable(
 num_spheres=5000,
 compFricDegree = 30, 
 unknownOk=True
)

from yade.params import table
num_spheres=table.num_spheres
compFricDegree = table.compFricDegree 
damp=0.2 
young=5e6 # contact stiffness
mn,mx=Vector3(-50,-50,-50),Vector3(50,50,50) # corners of the initial packing

## create materials for spheres and plates
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'))

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

## use a SpherePack object to generate a psd loose particles packing
global sp
sp=pack.SpherePack()
sp.makeCloud(mn,mx,num=6000,psdSizes=[1,2,2.25,2.5,3,4,6],psdCumm=[0.,0.1,0.3,0.3,.3,.7,1.]) 
sp.toSimulation(material='spheres')

### DEFINING ENGINES ###

triax=TriaxialStressController(
 thickness = 0,
 stressMask = 7,
 internalCompaction=False, 
 label='controller'
)

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()]
 ),

 PyRunner(command='stop()',iterPeriod=10,label='checker'),
 GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8),
 triax,
 newton
]

#Display spheres with 2 colors for seeing rotations better
Gl1_Sphere.stripes=0
if nRead==0: yade.qt.Controller(), yade.qt.View()

### APPLYING CONFINING PRESSURE ###

triax.goal1=triax.goal2=triax.goal3=-10000

def stop():
 if O.iter<100:return
 controller.dead=True,
 checker.command='gravityDeposition()'

def gravityDeposition():
  pred=pack.inCylinder((0,0,0),(0,0,H),Ro)-pack.inCylinder((0,0,0),(0,0,Hs),Rs)-pack.inCylinder((0,0,0),(0,0,H),Ri)
  assembly=pack.filterSpherePack(pred,sp,True)
  assembly.toSimulation()

#...connect to next steps in simulation
---------------------------------------------------
Thanks for the help in advance!



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