New question #685604 on Yade:
https://answers.launchpad.net/yade/+question/685604
Hello everyone,
I am trying to simulate the rock cutting process with a disk cutter.
During the cut the disk translates and rotates. I have done that by using
Kinematic Engine.
The problem is with the geometry.
When disk rotates, deforms. The facets forming the disk seem to detach.
I have created the geometry (Solid), with 3 different ways (Blender, 3d builder
and Autocad) without solving the problem.
Any suggestions on how can I fix it;
I am wondering it might affect forces exerted on the disk.
I am using Ubuntu 18.04 and Yade 2018.02b.
Thank you
I am sending the following: A file of the disk geometry in .stl format, and my
code.
https://1drv.ms/u/s!AiKcYaY3wMDqgV9IE7I2RFUWVTxp
from __future__ import print_function
from __future__ import division
from yade import pack, plot, geom, pack,utils,ymport,export,bodiesHandling
from yade.pack import *
from yade import _packPredicates
import math
from yade import *
# SIMULATIONS DEFINED HERE
Simulation
OUT='LinearCutTest_JCFPM'
Simulation Control
saveVTK=1 # saving output files for paraview
Material microproperties
readParamsFromTable(noTableOk=True, # unknownOk=True,
Sphere_Radius = 1.5e-3,
intR=1.25, # allows near neighbour interaction (GammaInt)
DENSITY=2700, # Density of the material (kg/m^3),could be adapted to
match material density:
dens_DEM=dens_rock*(V_rock/V_particles)=dens_rock*1/(1-poro_DEM) -> packing
porosity as to be computed?
YOUNG=68e9, # Eeq(GPa),elastic modulus
FRICTION_ANGLE=12, #(Degrees),Contact friction angle
POISSON=1,
TENS=22e6, #(Tensile Strenght T (MPa)),Defines the maximum admissible
normal force in traction in the matrix (FnMax = tensileStrength *
crossSection). (Pa)
COH=220e6, #(Local Cohesion C (MPa)),Defines the maximum admissible
tangential force in shear, for Fn=0, in the matrix (FsMax = cohesion *
crossSection). (Pa)
### Cutting_Specimen_dimensions
X = 54.85e-3,
Y=54.85e-3,
Z=180e-3,
)
from yade.params.table import *
material definition
Sample = O.materials.append(JCFpmMat(
young=YOUNG,
poisson=POISSON,
frictionAngle=radians(FRICTION_ANGLE),
cohesion=COH,
tensileStrength=TENS,
density = DENSITY,
label='spheres'
))
create the specimen
specimen=pack.randomDensePack(
pack.inAlignedBox((0,0,0),(X,Y,Z)),
radius = Sphere_Radius,
spheresInCell = 1000,
material=Sample,
rRelFuzz=0.34,
memoizeDb = '/tmp/Linear-Cutting_Test.db',
returnSpherePack = True,
)
specimen.toSimulation()
Disk Creation
Disk=ymport.stl('./p(5mm).stl')
O.bodies.append(Disk)
ids = [b.id for b in Disk]
# ENGINES DEFINED HERE
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=intR,label='Saabb'),Bo1_Facet_Aabb()],verletDist=.05*Sphere_Radius),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=intR,label='SSgeom'),Ig2_Facet_Sphere_ScGeom()],
[Ip2_JCFpmMat_JCFpmMat_JCFpmPhys(cohesiveTresholdIteration=1,label='interactionPhys')],
[Law2_ScGeom_JCFpmPhys_JointedCohesiveFrictionalPM(recordCracks=True,Key=OUT,label='interactionLaw')]
),
GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=10,timestepSafetyCoefficient=0.5,defaultDt=utils.PWaveTimeStep()),
NewtonIntegrator(damping=0.5,label='newton'),
PyRunner(iterPeriod=int(100),initRun=True,command='recorder()',label='data'),
VTKRecorder(iterPeriod=int(saveVTK),initRun=True,fileName=OUT+'-',recorders=['spheres','jcfpm','cracks','facets'],Key=OUT,label='vtk'),
PyRunner(iterPeriod=int(100), command='Stop()',label='data'),
CombinedKinematicEngine(ids=ids,comb=[
TranslationEngine(translationAxis=[0,0,1],velocity=-580),
RotationEngine(angularVelocity=6700,rotationAxis=[1,0,0],rotateAroundZero=False)],label='Eng')
]
# RECORDER DEFINED HERE
def recorder():
global Fz, Fx, Fy
global dz
Fz = 0.0
Fz = abs(sum(O.forces.f(facet.id)[2] for facet in Disk))
Fx = abs(sum(O.forces.f(facet.id)[0] for facet in Disk))
Fy = abs(sum(O.forces.f(facet.id)[1] for facet in Disk))
yade.plot.addData({'i':O.iter,
'FS':Fx,
'FN':Fy,
'FR':Fz,
'dz': abs(Disk[2].state.pos[2]),
'tc':interactionLaw.nbTensCracks,
'sc':interactionLaw.nbShearCracks,
'te':interactionLaw.totalTensCracksE,
'se':interactionLaw.totalShearCracksE,
'unbF':utils.unbalancedForce()})
plot.saveDataTxt(OUT)
def Stop():
if Disk[2].state.pos[2] == 0:
O.pause()
# if you want to plot during simulation
plot.plots={'dz':('FR','FN')}
plot.plot()
manage interaction detection factor during the first timestep and then set
default interaction range ((cf. A DEM model for soft and hard rock, Scholtes &
Donze, J
