How to use PSD
Hi,
I'm trying to generate an assembly with PSD like Fig. 9 in [1] or Fig. 1 in [2]. Firstly, I set distributeMass = True, then, I pick up several point (xi,yi) from Fig. 9 in [1] or Fig. 1 in [2] and make psdSizes=
1. Should I set distributeMass = True or False.
2. In TriaxialStressC
3. By the way, I'm very curious about how it is achieved in Fig. 9 in [1], the numerical PSD is almostly agreed with experimental PSD, is there no particle growing during the isotropic compaction phase?
Thanks a lot.
Leonard
[1]https:/
[2]https:/
[3]https:/
Question information
- Language:
- English Edit question
- Status:
- Solved
- For:
- Yade Edit question
- Assignee:
- No assignee Edit question
- Solved by:
- Leonard
- Solved:
- 2019-11-26
- Last query:
- 2019-11-26
- Last reply:
- 2019-11-25
Robert Caulk (rcaulk) said : | #1 |
Hello,
>Should I set distributeMass = True or False.
Depends on what you want to simulate. Do you want the psd distribution applied to particle count or mass fraction? Quote from the doc[1]:
"By default (with distributeMass=
> I wonder if all the particles are scaled up with the same scalar?
If internalCompact
> is there no particle growing during the isotropic compaction phase?
Maybe they used internalCompact
Cheers,
Robert
[1]https:/
[2]https:/
[3]https:/
Leonard (z2521899293) said : | #2 |
Hi Robert,
Many thanks for your reply.
>Depends on what you want to simulate.
What I want to simulate is the common PSD curve for a soil. For a general particle size distribution curve of soil, the Y-axis is percentage passing by mass, the x-axis is particle size (diameter) based on what I understand.
What I am confused is whether the distributeMass command controls on Y-axis or on X-axis?
For example, if distributeMass command controls on Y-axis, it may mean that percentage passing by mass (distributeMass
If distributeMass command controls on X-axis, it may mean that X-axis is particle diameter (distributeMass
>spheres using a common multiplier
Thanks, it is clear.
>Maybe they used internalCompact
I'm still interested in how it is achieved by setting internalCompact
I have also tried internalCompact
For example, the size of initial packing is 0.7*0.7*1.4 (mn,mx=
###########
from yade import pack, plot
nRead=readParam
num_spheres=1000,
compFricDegree = 30,
key='_
unknownOk=True
)
from yade.params import table
num_spheres=
key=table.key
targetPorosity = 0.43
compFricDegree = table.compFricD
finalFricDegree = 30
rate=-0.02
damp=0.2
stabilityThresh
young=5e6
mn,mx=Vector3(
O.materials.
O.materials.
walls=aabbWalls
wallIds=
sp=pack.
sp.makeCloud(
O.bodies.
Gl1_Sphere.
### DEFINING ENGINES ###
triax=TriaxialS
maxMultiplier=
finalMaxMultip
thickness = 0,
stressMask = 7,
internalCompac
)
newton=
O.engines=[
ForceResetter(),
InsertionSortC
InteractionLoop(
[Ig2_
[Ip2_
[Law2_
),
GlobalStiffnes
triax,
newton
]
Gl1_Sphere.
if nRead==0: yade.qt.
### APPLYING CONFINING PRESSURE ###
triax.goal1=
while 1:
O.run(1000, True)
unb=unbalanced
print 'unbalanced force:',unb,' mean stress: ',triax.meanStress
if unb<stabilityTh
break
print "### Isotropic state saved ###"
### REACHING A SPECIFIED POROSITY PRECISELY ###
import sys
while triax.porosity>
# we decrease friction value and apply it to all the bodies and contacts
compFricDegree = 0.95*compFricDegree
setContactFric
print "\r Friction: ",compFricDegree," porosity:
sys.stdout.flush()
O.run(500,1)
print "### Compacted state saved ###"
#######
Cheers,
Leonard
Robert Caulk (rcaulk) said : | #3 |
distributeMass=True ensures your PSD is mass percent passing instead of particle count percent passing.
Leonard (z2521899293) said : | #4 |
Thanks Robert, this solved my problem, and I will open a new question about my last doubt.
Cheers,
Leonard