Modeling 2 materilas by CPM model

Hi Seti,

something like this?
##############
from yade import pack
import random

mat1 = CpmMat() # ...
mat2 = CpmMat() # ...

sp =
pack.randomDensePack(pack.inAlignedBox((0,0,0),(1,1,1)),radius=.05,spheresInCell=500,returnSpherePack=True)
sp.toSimulation()

for b in O.bodies:
if random.random() < 0.2:
b.mat = mat1
b.shape.color = (1,0,0)
else:
b.mat = mat2
b.shape.color = (0,1,1)
##############

cheers
Jan

2016-10-31 12:14 GMT+01:00 Seti <email address hidden>:

> New question #403663 on Yade:
> https://answers.launchpad.net/yade/+question/403663
>
> Hi All,
>
> I have the same question which has been asked in Q # 372295. I really
> need to know how I can control the percentage of spheres when I am
> modelling different materials through CPM model.
>
> Can you please shed some lights on this issue?
>
>
> Cheers,
> Seti
>
> --
> You received this question notification because your team yade-users is
> an answer contact for Yade.
>
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Hi Jan,

Thanks so much for your reply, would you please let me know what is meaning of " if random.random() < 0.2:" commend in your example?

I have tried to do a quick test based on your recommendation, below error will be pop up related to "if random.random() < 0.2:" line

"IndentationError: expected an indented block"

Cheers,
Seti

Hi Seti,

random.random() returns uniform distribution random number in the range
(0,1), so random.random()<0.2 means that 0.2=20/100=20% of spheres will
have mat1, the rest 80% mat2. You can use of course any other value than
0.2.

The indentation error comes from your script, probably from copy-paste
process. I will rewrite the code with only spaces (I used tabs originally)
co copy-paste again should work. Please try it and let us know.

##############
from yade import pack
import random

mat1 = CpmMat() # ...
mat2 = CpmMat() # ...

sp = pack.randomDensePack(pack.inAlignedBox((0,0,0),(1,1,1)),
radius=.05,spheresInCell=500,returnSpherePack=True)
sp.toSimulation()

for b in O.bodies:
  if random.random() < 0.2:
    b.mat = mat1
    b.shape.color = (1,0,0)
  else:
    b.mat = mat2
  b.shape.color = (0,1,1)
##############

cheers
Jan

2016-10-31 13:23 GMT+01:00 Seti <email address hidden>:

> Question #403663 on Yade changed:
> https://answers.launchpad.net/yade/+question/403663
>
> Status: Answered => Open
>
> Seti is still having a problem:
> Hi Jan,
>
> Thanks so much for your reply, would you please let me know what is
> meaning of " if random.random() < 0.2:" commend in your example?
>
> I have tried to do a quick test based on your recommendation, below
> error will be pop up related to "if random.random() < 0.2:" line
>
> "IndentationError: expected an indented block"
>
>
> Cheers,
> Seti
>
> --
> You received this question notification because your team yade-users is
> an answer contact for Yade.
>
> _______________________________________________
> Mailing list: https://launchpad.net/~yade-users
> Post to : <email address hidden>
> Unsubscribe : https://launchpad.net/~yade-users
> More help : https://help.launchpad.net/ListHelp
>

Thanks heaps Jan, it is working quite well.

Thanks Jan Stránský, that solved my question.

Hi Jan,

Just a quick question, I am wondering to combine more materials in CPM model ( say 5 items), would you please advise me how I can specify the percentage of each material?
My idea is as per below:

##############
from yade import pack
import random

mat1 = CpmMat() # ...
mat2 = CpmMat() # ...
mat3 = CpmMat() # ...
mat4 = CpmMat() # ...
mat5 = CpmMat() # ...

sp = pack.randomDensePack(pack.inAlignedBox((0,0,0),(1,1,1)),
radius=.05,spheresInCell=500,returnSpherePack=True)
sp.toSimulation()

for b in O.bodies:
  if random.random() < 0.2:
    b.mat = mat1
    b.shape.color = (1,0,0)
 elif random.random() < 0.1:
    b.mat = mat2
    b.shape.color = (0,1,0)
 elif random.random() < 0.3:
    b.mat = mat3
    b.shape.color = (0,0,1)
 elif random.random() < 0.2:
    b.mat = mat4
    b.shape.color = (1,1,0)
  else:
    b.mat = mat5
  b.shape.color = (0,1,1)

Cheers,
Seti

Hi Seti,

for b in O.bodies:
> if random.random() < 0.2:
> b.mat = mat1
> b.shape.color = (1,0,0)
> elif random.random() < 0.1:
> b.mat = mat2
> b.shape.color = (0,1,0)

1) you should use only one random.random() call within the if-else structure
2) then you should use different numbers (if it was <0.2, else if <0.1 does
not make sense)

something like:

###############
r = random.random()
if r < 0.2: ... # 0-20%, in total 20 %
else if r < 0.3: ... # 20%-30%, in total 10%
else if r < 0.6: ... # 30 % - 60%, in total 30%
....
###############

cheers
Jan

2016-11-13 11:12 GMT+01:00 Seti <email address hidden>:

> Question #403663 on Yade changed:
> https://answers.launchpad.net/yade/+question/403663
>
> Status: Solved => Open
>
> Seti is still having a problem:
> Hi Jan,
>
> Just a quick question, I am wondering to combine more materials in CPM
> model ( say 5 items), would you please advise me how I can specify the
> percentage of each material?
> My idea is as per below:
>
> ##############
> from yade import pack
> import random
>
> mat1 = CpmMat() # ...
> mat2 = CpmMat() # ...
> mat3 = CpmMat() # ...
> mat4 = CpmMat() # ...
> mat5 = CpmMat() # ...
>
> sp = pack.randomDensePack(pack.inAlignedBox((0,0,0),(1,1,1)),
> radius=.05,spheresInCell=500,returnSpherePack=True)
> sp.toSimulation()
>
> for b in O.bodies:
> if random.random() < 0.2:
> b.mat = mat1
> b.shape.color = (1,0,0)
> elif random.random() < 0.1:
> b.mat = mat2
> b.shape.color = (0,1,0)
> elif random.random() < 0.3:
> b.mat = mat3
> b.shape.color = (0,0,1)
> elif random.random() < 0.2:
> b.mat = mat4
> b.shape.color = (1,1,0)
> else:
> b.mat = mat5
> b.shape.color = (0,1,1)
>
>
> Cheers,
> Seti
>
> --
> You received this question notification because your team yade-users is
> an answer contact for Yade.
>
> _______________________________________________
> Mailing list: https://launchpad.net/~yade-users
> Post to : <email address hidden>
> Unsubscribe : https://launchpad.net/~yade-users
> More help : https://help.launchpad.net/ListHelp
>

Hi Jan,

Thanks for your help, , in a sample with just two materials. I have done a series of parametric studies to understand how changing( say increasing) the percentage of material #1 has effect on the strength of sample. By increasing the percentage of mat 1 ( %10, %30, %70) the strength of sample has been increased respectively. However when I increase the percentage of mat 1 to 90% I have drop in stress - strain curve ( strength even less that 30 %)

Is there any issue with the script or there is a convergence problem here?

Thanks so much for your help.

############
#!/usr/bin/python
# -*- coding: utf-8 -*-
from __future__ import division

from yade import plot,pack,timing
import time, sys, os, copy

#import matplotlib
#matplotlib.rc('text',usetex=True)
#matplotlib.rc('text.latex',preamble=r'\usepackage{concrete}\usepackage{euler}')

"""
A fairly complex script performing uniaxial tension-compression test on hyperboloid-shaped specimen.
Most parameters of the model (and of the setup) can be read from table using yade-multi.
After the simulation setup, tension loading is run and stresses are periodically saved for plotting
as well as checked for getting below the maximum value so far. This indicates failure (see stopIfDamaged
function). After failure in tension, the original setup is loaded anew and the sense of loading reversed.
After failure in compression, strain-stress curves are saved via plot.saveGnuplot and we exit,
giving some useful information like peak stresses in tension/compression.
Running this script for the first time can take long time, as the specimen is prepared using triaxial
compression. Next time, however, an attempt is made to load previously-generated packing
(from /tmp/triaxPackCache.sqlite) and this expensive procedure is avoided.
The specimen length can be specified, its diameter is half of the length and skirt of the hyperboloid is
4/5 of the width.
The particle size is constant and can be specified using the sphereRadius parameter.
The 3d display has displacement scaling applied, so that the fracture looks more spectacular. The scale
is 1000 for tension and 100 for compression.
"""

# default parameters or from table
readParamsFromTable(noTableOk=True, # unknownOk=True,
 young=30e9,
 poisson=.2,

 sigmaT=1.1e9,
 frictionAngle=atan(.57),
 epsCrackOnset=1e-4,
 relDuctility=30,

 intRadius=1.5,
 dtSafety=.8,
 damping=0.4,
 strainRateTension=.00001,
 strainRateCompression=.00001,
 setSpeeds=True,
 # 1=tension, 2=compression (ANDed; 3=both)
 doModes=2,

 specimenLength=.15,
 sphereRadius=3.5e-3,

 # isotropic confinement (should be negative)
 isoPrestress=0,
)

from yade.params.table import *

if 'sigmaT=3.5e6, compression' in O.tags.keys(): O.tags['id']=O.tags['id']+O.tags['sigmaT=3.5e6, compression']

# make geom; the dimensions are hard-coded here; could be in param table if desired
# z-oriented hyperboloid, length 20cm, diameter 10cm, skirt 8cm
# using spheres 7mm of diameter
mat1=CpmMat(young=young,frictionAngle=atan(.32),poisson=poisson,density=4800,sigmaT=sigmaT,relDuctility=relDuctility,epsCrackOnset=epsCrackOnset,isoPrestress=isoPrestress)
mat2=CpmMat(young=30e9,frictionAngle=frictionAngle,poisson=poisson,density=4800,sigmaT=sigmaT,relDuctility=relDuctility,epsCrackOnset=epsCrackOnset,isoPrestress=isoPrestress)
concreteId1=O.materials.append(CpmMat(young=young,frictionAngle=atan(.32),poisson=poisson,density=4800,sigmaT=sigmaT,relDuctility=relDuctility,epsCrackOnset=epsCrackOnset,isoPrestress=isoPrestress))
concreteId2=O.materials.append(CpmMat(young=young,frictionAngle=frictionAngle,poisson=poisson,density=4800,sigmaT=sigmaT,relDuctility=relDuctility,epsCrackOnset=epsCrackOnset,isoPrestress=isoPrestress))
#sp=pack.randomDensePack(pack.inHyperboloid((0,0,-.5*specimenLength),(0,0,.5*specimenLength),.25*specimenLength,.17*specimenLength),spheresInCell=2000,radius=sphereRadius,memoizeDb='/tmp/triaxPackCache.sqlite',returnSpherePack=True)

#############################
sp=pack.SpherePack()
pred=pack.inCylinder((0,0,0.002),(0,0,0.3),0.05)
O.bodies.append(pack.randomDensePack(pred,radius=0.008))

#pred=pack.inCylinder((0,0,0),(0,0,0.2),0.1)

#sp=pack.randomDensePack(pred,radius=0.002,material=concreteId)
#O.bodies.append(TS1)
##############

#sp=pack.randomDensePack(pack.inAlignedBox((-.25*specimenLength,-.25*specimenLength,-.5*specimenLength),(.25*specimenLength,.25*specimenLength,.5*specimenLength)),spheresInCell=2000,radius=sphereRadius,memoizeDb='/tmp/triaxPackCache.sqlite',returnSpherePack=True)

sp.toSimulation()

for b in O.bodies:
  if random.random() < 0.3:
    b.mat = mat1
    b.shape.color = (1,0,0)
  else:
    b.mat = mat2
    b.shape.color = (0,1,1)

bb=uniaxialTestFeatures()
negIds,posIds,axis,crossSectionArea=bb['negIds'],bb['posIds'],bb['axis'],bb['area']
O.dt=dtSafety*PWaveTimeStep()

print 'Timestep',O.dt
print 'sigmaT=MatchMaker(matches=((concreteId1,concreteId1,1.1e9),(concreteId1,concreteId2,1.1e9),(concreteId2,concreteId2,1.1e3)),0.33, compression'
mm,mx=[pt[axis] for pt in aabbExtrema()]
coord_25,coord_50,coord_75=mm+.25*(mx-mm),mm+.5*(mx-mm),mm+.75*(mx-mm)
area_25,area_50,area_75=approxSectionArea(coord_25,axis),approxSectionArea(coord_50,axis),approxSectionArea(coord_75,axis)

O.engines=[
 ForceResetter(),
 InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=intRadius,label='is2aabb'),],verletDist=.05*sphereRadius),
 InteractionLoop(
  [Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=intRadius,label='ss2sc')],
  [Ip2_CpmMat_CpmMat_CpmPhys(sigmaT=MatchMaker(matches=((concreteId1,concreteId1,1.1e9),(concreteId1,concreteId2,1.1e9),(concreteId2,concreteId2,1.1e3))))],
                #[Ip2_CpmMat_CpmMat_CpmPhys(relDuctility=MatchMaker(matches=((concreteId1,concreteId1,30),(concreteId1,concreteId2,40),(concreteId2,concreteId2,50))))],
                #[Ip2_CpmMat_CpmMat_CpmPhys(young=MatchMaker(matches=((concreteId1,concreteId2,30e9),(concreteId2,concreteId2,30e8))))]
  [Law2_ScGeom_CpmPhys_Cpm()],
 ),
 NewtonIntegrator(damping=damping,label='damper'),
 CpmStateUpdater(realPeriod=.5),
 UniaxialStrainer(strainRate=strainRateTension,axis=axis,asymmetry=0,posIds=posIds,negIds=negIds,crossSectionArea=crossSectionArea,blockDisplacements=False,blockRotations=False,setSpeeds=setSpeeds,label='strainer'),
 PyRunner(virtPeriod=1e-6/strainRateTension,realPeriod=1,command='addPlotData()',label='plotDataCollector',initRun=True),
 PyRunner(realPeriod=4,command='stopIfDamaged()',label='damageChecker'),
]
#O.miscParams=[Gl1_CpmPhys(dmgLabel=False,colorStrain=False,epsNLabel=False,epsT=False,epsTAxes=False,normal=False,contactLine=True)]

# plot stresses in ¼, ½ and ¾ if desired as well; too crowded in the graph that includes confinement, though
plot.plots={'eps':('sigma',)} #,'sigma.50')},'t':('eps')} #'sigma.25','sigma.50','sigma.75')}

O.saveTmp('initial');

O.timingEnabled=False

global mode
mode='tension' if doModes & 1 else 'compression'

def initTest():
 global mode
 print "init"
 if O.iter>0:
  O.wait();
  O.loadTmp('initial')
  print "Reversing plot data"; plot.reverseData()
 else: plot.plot(subPlots=False)
 strainer.strainRate=abs(strainRateTension) if mode=='tension' else -abs(strainRateCompression)
 try:
  from yade import qt
  renderer=qt.Renderer()
  renderer.dispScale=(1000,1000,1000) if mode=='tension' else (100,100,100)
 except ImportError: pass
 print "init done, will now run."
 O.step(); # to create initial contacts
 # now reset the interaction radius and go ahead
 ss2sc.interactionDetectionFactor=1.
 is2aabb.aabbEnlargeFactor=1.

 O.run()
###########

#################

def stopIfDamaged():
 global mode
 if O.iter<2 or not plot.data.has_key('sigma'): return # do nothing at the very beginning
 sigma,eps=plot.data['sigma'],plot.data['eps']
 extremum=max(sigma) if (strainer.strainRate>0) else min(sigma)
 minMaxRatio=0.5 if mode=='tension' else 0.5
 if extremum==0: return
 import sys; sys.stdout.flush()
 if abs(sigma[-1]/extremum)<minMaxRatio or abs(strainer.strain)>(5e-3 if isoPrestress==0 else 5e-2):
  if mode=='tension' and doModes & 2: # only if compression is enabled
   mode='compression'
   O.save('/tmp/uniax-tension.yade.gz')
   print "Saved /tmp/uniax-tension.yade.gz (for use with interaction-histogram.py and uniax-post.py)"
   print "Damaged, switching to compression... "; O.pause()
   # important! initTest must be launched in a separate thread;
   # otherwise O.load would wait for the iteration to finish,
   # but it would wait for initTest to return and deadlock would result
   import thread; thread.start_new_thread(initTest,())
   return
  else:
   print "Damaged, stopping."
   ft,fc=max(sigma),min(sigma)
   print 'Strengths fc=%g, ft=%g, |fc/ft|=%g'%(fc,ft,abs(fc/ft))
   title=O.tags['sigmaT=3.5e6, compression'] if 'sigmaT=3.5e6, compression' in O.tags.keys() else O.tags['params']
   print 'gnuplot',plot.saveGnuplot(O.tags['id'],title=title)
   print 'Bye.'
                        print 'sigmaT=MatchMaker(matches=((concreteId1,concreteId1,1.1e9),(concreteId1,concreteId2,1.1e9),(concreteId2,concreteId2,1.1e3))),.33, compression'
   O.pause()
   #sys.exit(0) # results in some threading exception

def addPlotData():
 yade.plot.addData({'t':O.time,'i':O.iter,'eps':strainer.strain,'sigma':strainer.avgStress+isoPrestress,
  'sigma.25':forcesOnCoordPlane(coord_25,axis)[axis]/area_25+isoPrestress,
  'sigma.50':forcesOnCoordPlane(coord_50,axis)[axis]/area_50+isoPrestress,
  'sigma.75':forcesOnCoordPlane(coord_75,axis)[axis]/area_75+isoPrestress,
  })
plot.plot(subPlots=False)
#O.run()
initTest()
waitIfBatch()
O.run(50000,True)
plot.plots={'eps':('sigma')}
plot.plot(subPlots=False)
plot.saveDataTxt('sigmaT=MatchMaker(matches=((concreteId1,concreteId1,1.1e9),(concreteId1,concreteId2,1.1e9),(concreteId2,concreteId2,1.1e3)),0.33, compression')

Cheers,
Seti

Hi Seti,

you should have one instance for each material, i.e.

mat1 = ....
concreteId1 = O.materials.append(mat1) # not another CpmMat...

otherwise the matches does not work (mathes are based on mat.id, you can
try to print O.materials[1].id and mat2.id)
​
cheers
Jan