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# encoding: utf-8
# default material parameters
readParamsFromTable(
# no. of your simulation
key=0,
# Density
rho=2450,
# Exponent of Young's modulus
E_m=9.3,
# Poisson's ratio
nu=0.2,
# final friction coefficient
mu=0.4,
# timestepSafetyCoefficient
safe=0.1,
)
# import modules
import numpy as np
from yade.params import table
from yade import plot
from grainlearning.tools import write_dict_to_file
# check if run in batch mode
isBatch = runningInBatch()
if isBatch:
description = O.tags['description']
else:
description = 'collision_test_run'
# glass bead parameters (units: ug->1e-9kg; mm->1e-3m; ms->1e-3s)
lenScale = 1e3 # length in mm <- 1e-3 m
sigScale = 1 # Stress in ug/(mm*ms^2) <- Pa
rhoScale = 1 # Density in ug/mm^3 <- kg/m^3
# function to save simulation data and stop simulation
def add_sim_data():
# get interaction force between particle 1 and particle 2
inter = O.interactions[0, 1]
# get penetration depth
u = inter.geom.penetrationDepth
plot.addData(u=u, f=inter.phys.normalForce.norm())
# move particle 1
O.bodies[1].state.pos = O.bodies[1].state.refPos + Vector3(0, 0, -obs_ctrl_data.pop())
if not obs_ctrl_data:
data_file_name = f'{description}_sim.txt'
data_param_name = f'{description}_param.txt'
# initialize data dictionary
param_data = {}
for name in table.__all__:
param_data[name] = eval('table.' + name)
# write simulation data into a text file
write_dict_to_file(plot.data, data_file_name)
write_dict_to_file(param_data, data_param_name)
O.pause()
obs_file = "collision_obs.txt"
# define a load sequence
obs_ctrl_data = np.linspace(0.002, 0.01, 81).tolist()
obs_ctrl_data.reverse()
# create dictionary to store simulation data
plot.plots = {'u': 'f'}
# create materials
O.materials.append(FrictMat(young=pow(10, table.E_m), poisson=table.nu, frictionAngle=atan(table.mu), density=table.rho))
# create two particles
O.bodies.append(sphere(Vector3(0, 0, 0), 1, material=0, fixed=True))
O.bodies.append(sphere(Vector3(0, 0, 2), 1, material=0, fixed=True))
# define engines
O.engines = [
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb()]),
InteractionLoop([Ig2_Sphere_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_MindlinPhys()], [Law2_ScGeom_MindlinPhys_Mindlin()]),
NewtonIntegrator(damping=0.0, label='newton'),
# needs to add module collision before function name
PyRunner(command='add_sim_data()', iterPeriod=1)
]
# set initial timestep
O.dt = table.safe * PWaveTimeStep()
# move particle 1
O.bodies[1].state.pos = O.bodies[1].state.refPos + Vector3(0, 0, -obs_ctrl_data.pop())
# run DEM simulation
O.run()
waitIfBatch()
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