[Yade-users] [Question #294036]: Rate of strain between compressive and tensile strength using CpmMat.
New question #294036 on Yade:
https://answers.launchpad.net/yade/+question/294036
Hello everyone,
I looked up document information and found that the concrete’s strain at
maximum compressive strength is about 0.0033 and the strain at maximum tensile
strength is about 0.00015. The rate of compressive strain and tensile strain is
about 20. I used the following code to compress the concrete and tense it and I
found from the diagram that the rate is about 2. I tried to change the rate by
modifying the parameters, but I failed. Can you give me some suggestion about
how to change the rate between the strain at maximum compressive strength and
the strain at maximum tensile strength?
#first code, calculate the strain at
maximum compressive strength
#!/usr/bin/python
import string
from yade import plot,qt
from yade.pack import *
from yade import pack, plot
O.materials.append(CpmMat(young=24e9,frictionAngle=atan(0.8),poisson=.2,sigmaT=3.5e6,relDuctility=30,epsCrackOnset=1e-4))
initSize=1.2
sp=pack.randomPeriPack(radius=.05,initSize=Vector3(initSize,initSize,initSize))
sp.toSimulation()
O.save('/tmp/hh.gz')
plot.plots={'ex':('sx',)}
def plotAddData():
plot.addData(
sx=p3d.stress[0],
ex=p3d.strain[0],
)
O.dt=PWaveTimeStep()/2
EnlargeFactor=1.5
EnlargeFactor=1.0
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=EnlargeFactor,label='bo1s')]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=EnlargeFactor,label='ig2ss')],
[Ip2_CpmMat_CpmMat_CpmPhys()],[Law2_ScGeom_CpmPhys_Cpm()]),
NewtonIntegrator(),
Peri3dController(
nSteps=4000,
# how many time steps the simulation will last
# after reaching nSteps
do doneHook action
doneHook='print
"Simulation with Peri3dController finished."; O.pause()',
# the prescribed path
(step,value of stress/strain) can be defined in absolute values
# or in relative values
# if the goal value is
0, the absolute stress/strain values are always considered (step values remain
relative)
# if ##Path is not
explicitly defined, it is considered as linear function between (0,0) and
(nSteps,goal)
# as in yzPath and
xyPath
# the relative values
are really relative (zxPath gives the same - except of the sign from goal value
- result as yyPath)
# variables used in the
first step
label='p3d'
),
PyRunner(command='plotAddData()',iterPeriod=1),
]
p3d.stressMask=0b10 # prescribed ex,ey,sz,syz,ezx,sxy; e..strain;
s..stress
p3d.goal=(-0.005,0,0,0,0,0) #xx, yy, zz, yz, zx, xy
O.step()
bo1s.aabbEnlargeFactor=ig2ss.interactionDetectionFactor=1.
O.run(); O.wait()
plot.plot(subPlots=False)
#second code, calculate the strain at
maximum tensile strength
#!/usr/bin/python
import string
from yade import plot,qt
from yade.pack import *
from yade import pack, plot
O.load('/tmp/hh.gz')
plot.plots={'ex':('sx',)}
def plotAddData():
plot.addData(
sx=p3d.stress[0],
ex=p3d.strain[0],
)
O.dt=PWaveTimeStep()/2
EnlargeFactor=1.5
EnlargeFactor=1.0
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=EnlargeFactor,label='bo1s')]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=EnlargeFactor,label='ig2ss')],
[Ip2_CpmMat_CpmMat_CpmPhys()],[Law2_ScGeom_CpmPhys_Cpm()]),
NewtonIntegrator(),
Peri3dController(
nSteps=4000,
# how many time steps the simulation will last
# after reaching nSteps
do doneHook action
Re: [Yade-users] [Question #294036]: Rate of strain between compressive and tensile strength using CpmMat.
Question #294036 on Yade changed:
https://answers.launchpad.net/yade/+question/294036
Status: Open => Answered
Jan Stránský proposed the following answer:
Hello,
two notes:
1) EnlargeFactor=1.0 generates very loose interaction network. The CPM
model was developed and tested for EnlargeFactor=1.5
2) I am not sure if periodic simulation is the best choice for compressive
simulations (as the cracks would not be periodic), you can also try
non-periodic simulation, see e.g. [1]
cheers
Jan
[1] https://github.com/yade/trunk/blob/master/examples/concrete/uniax.py
2016-05-22 14:46 GMT+02:00 liukeqi
:
> New question #294036 on Yade:
> https://answers.launchpad.net/yade/+question/294036
>
> Hello everyone,
> I looked up document information and found that the concrete’s strain at
> maximum compressive strength is about 0.0033 and the strain at maximum
> tensile strength is about 0.00015. The rate of compressive strain and
> tensile strain is about 20. I used the following code to compress the
> concrete and tense it and I found from the diagram that the rate is about
> 2. I tried to change the rate by modifying the parameters, but I failed.
> Can you give me some suggestion about how to change the rate between the
> strain at maximum compressive strength and the strain at maximum tensile
> strength?
>
> #first code, calculate the strain
> at maximum compressive strength
> #!/usr/bin/python
> import string
> from yade import plot,qt
> from yade.pack import *
> from yade import pack, plot
>
> O.materials.append(CpmMat(young=24e9,frictionAngle=atan(0.8),poisson=.2,sigmaT=3.5e6,relDuctility=30,epsCrackOnset=1e-4))
>
> initSize=1.2
>
>
> sp=pack.randomPeriPack(radius=.05,initSize=Vector3(initSize,initSize,initSize))
>
> sp.toSimulation()
>
> O.save('/tmp/hh.gz')
>
> plot.plots={'ex':('sx',)}
> def plotAddData():
> plot.addData(
> sx=p3d.stress[0],
> ex=p3d.strain[0],
>
> )
>
>
> O.dt=PWaveTimeStep()/2
>
> EnlargeFactor=1.5
> EnlargeFactor=1.0
> O.engines=[
> ForceResetter(),
>
> InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=EnlargeFactor,label='bo1s')]),
> InteractionLoop(
>
> [Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=EnlargeFactor,label='ig2ss')],
> [Ip2_CpmMat_CpmMat_CpmPhys()],[Law2_ScGeom_CpmPhys_Cpm()]),
> NewtonIntegrator(),
> Peri3dController(
>
> nSteps=4000,
> # how many time steps the simulation will last
> # after reaching
> nSteps do doneHook action
> doneHook='print
> "Simulation with Peri3dController finished."; O.pause()',
>
> # the prescribed
> path (step,value of stress/strain) can be defined in absolute values
>
> # or in relative
> values
>
> # if the goal
> value is 0, the absolute stress/strain values are always considered (step
> values remain relative)
>
> # if ##Path is not
> explicitly defined, it is considered as linear function between (0,0) and
> (nSteps,goal)
> # as in yzPath and
> xyPath
> # the relative
> values are really relative (zxPath gives the same - except of the sign from
> goal value - result as yyPath)
>
>
> # variables used
> in the first step
> label='p3d'
> ),
> PyRunner(command='plotAddData()',iterPeriod=1),
>
> ]
>
> p3d.stressMask=0b10 # prescribed ex,ey,sz,syz,ezx,sxy;
> e..strain; s..stress
> p3d.goal=(-0.005,0,0,0,0,0) #xx, yy, zz, yz, zx, xy
> O.step()
> bo1s.aabbEnlargeFactor=ig2ss.interactionDetectionFactor=1.
> O.run(); O.wait()
> plot.plot(subPlots=False)
>
> #second code, calculate the strain
> at maximum tensile strength
> #!/usr/bin/python
> import string
> from yade import plot,qt
> from yade.pack import *
> from yade import pack, plot
>
>
> O.load('/tmp/hh.gz')
>
> plot.plots={'ex':('sx',)}
> def plotAddData():
> plot.addData(
> sx=p3d.stress[0],
> ex=p3d.strain[0],
>
> )
>
>
> O.dt=PWaveTimeStep()/2
>
> EnlargeFactor=1.5
> EnlargeFactor=1.0
> O.engines=[
> ForceResetter(),
>
> InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=EnlargeFactor,label='bo1s')]),
> InteractionLoop(
>
> [Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=EnlargeFactor,label='ig2ss')],
> [Ip2_CpmMat_Cp
Re: [Yade-users] [Question #294036]: Rate of strain between compressive and tensile strength using CpmMat.
Question #294036 on Yade changed: https://answers.launchpad.net/yade/+question/294036 Status: Answered => Solved liukeqi confirmed that the question is solved: Thanks Jan Stránský, that solved my question. I do not quiet understand the concept of "periodic simulation", for example, the information that you suggested "as the cracks would not be periodic". Could you recommend some documents about the concept of "periodic boundary" when it is convenience for you? -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #294036]: Rate of strain between compressive and tensile strength using CpmMat.
Question #294036 on Yade changed: https://answers.launchpad.net/yade/+question/294036 Jérôme Duriez posted a new comment: Sorry, the editors of the book are in fact Radjai and Dubois, vs Radjai and Voivret for that chapter... -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #294036]: Rate of strain between compressive and tensile strength using CpmMat.
Question #294036 on Yade changed: https://answers.launchpad.net/yade/+question/294036 Jérôme Duriez posted a new comment: For general documentation about periodic boundaries, you might give a look to http://www.cgp-gateway.org/resources/Articles/PBC.pdf (chapter of the book Discrete-element Modeling of Granular Materials, ISTE-Wiley, edited by the authors of this chapter) -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #294036]: Rate of strain between compressive and tensile strength using CpmMat.
Question #294036 on Yade changed: https://answers.launchpad.net/yade/+question/294036 liukeqi posted a new comment: Thanks Jan Stránský. I was very glad of your consistent help. -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
