Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F78007306
hertz.py
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Sat, Aug 17, 19:41
Size
4 KB
Mime Type
text/x-python
Expires
Mon, Aug 19, 19:41 (2 d)
Engine
blob
Format
Raw Data
Handle
19569956
Attached To
rTAMAAS tamaas
hertz.py
View Options
#!/usr/bin/python
# -*- coding: utf-8 -*-
##*
#
# @author Guillaume Anciaux <guillaume.anciaux@epfl.ch>
#
# @section LICENSE
#
# Copyright (©) 2016 EPFL (Ecole Polytechnique Fédérale de
# Lausanne) Laboratory (LSMS - Laboratoire de Simulation en Mécanique des
# Solides)
#
# Tamaas is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option) any
# later version.
#
# Tamaas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Tamaas. If not, see <http://www.gnu.org/licenses/>.
#
#
################################################################
import
tamaas
def
dumpHertzPrediction
(
file
,
bem
,
pressure
,
r
,
E
):
A
=
tamaas
.
SurfaceStatistics
.
computeContactArea
(
bem
.
getTractions
())
Aratio
=
tamaas
.
SurfaceStatistics
.
computeContactAreaRatio
(
bem
.
getTractions
())
radius
=
np
.
sqrt
(
A
/
np
.
pi
)
#L = bem.getSurface().getL()
L
=
1.
load
=
pressure
*
L
*
L
radius_hertz
=
pow
(
0.75
*
load
*
r
/
E
,
1.
/
3.
)
p0_hertz
=
1.
/
np
.
pi
*
pow
(
6.
*
E
*
E
*
load
/
r
/
r
,
1.
/
3.
)
p0
=
tamaas
.
SurfaceStatistics
.
computeMaximum
(
bem
.
getTractions
())
n
=
bem
.
getTractions
()
.
shape
[
0
]
computed_load
=
bem
.
getTractions
()
.
sum
()
/
n
/
n
*
L
*
L
file
.
write
(
"{0}
\t
{1}
\t
{2}
\t
{3}
\t
{4}
\t
{5}
\t
{6}
\t
{7}
\t
{8}
\t
{9}
\n
"
.
format
(
pressure
,
load
,
computed_load
,
Aratio
,
A
,
radius
,
radius_hertz
,
radius_hertz
/
radius
,
p0
,
p0_hertz
))
################################################################
def
main
(
argv
):
parser
=
argparse
.
ArgumentParser
(
description
=
'Hertz test for the Boundary element method of Stanley and Kato'
)
parser
.
add_argument
(
"--N"
,
type
=
int
,
help
=
"Surface size"
,
required
=
True
)
parser
.
add_argument
(
"--r"
,
type
=
float
,
help
=
"radius of hertz sphere"
,
required
=
True
)
parser
.
add_argument
(
"--steps"
,
type
=
int
,
help
=
"number of steps within which the pressure is applied."
,
required
=
True
)
parser
.
add_argument
(
"--precision"
,
type
=
float
,
help
=
"relative precision, convergence if | (f_i - f_{i-1})/f_i | < Precision."
,
required
=
True
)
parser
.
add_argument
(
"--e_star"
,
type
=
float
,
help
=
"effective elastic modulus"
,
required
=
True
)
parser
.
add_argument
(
"--L"
,
type
=
float
,
help
=
"size of the surface"
,
required
=
True
)
parser
.
add_argument
(
"--max_pressure"
,
type
=
float
,
help
=
"maximal load requested"
,
required
=
True
)
parser
.
add_argument
(
"--plot_surface"
,
type
=
bool
,
help
=
"request output of text files containing the contact pressures on the surface"
,
default
=
False
)
parser
.
add_argument
(
"--nthreads"
,
type
=
int
,
help
=
"request a number of threads to use via openmp to compute"
,
default
=
1
)
args
=
parser
.
parse_args
()
arguments
=
vars
(
args
)
n
=
arguments
[
"N"
]
r
=
arguments
[
"r"
]
max_pressure
=
arguments
[
"max_pressure"
]
Ninc
=
arguments
[
"steps"
]
epsilon
=
arguments
[
"precision"
]
Estar
=
arguments
[
"e_star"
]
L
=
arguments
[
"L"
]
plot_surface
=
arguments
[
"plot_surface"
]
nthreads
=
arguments
[
"nthreads"
]
pressure
=
0.
dp
=
max_pressure
/
float
(
Ninc
)
s
=
np
.
zeros
((
n
,
n
))
print
s
.
shape
for
i
in
range
(
0
,
n
):
for
j
in
range
(
0
,
n
):
x
=
1.
*
i
-
n
/
2
y
=
1.
*
j
-
n
/
2
d
=
(
x
*
x
+
y
*
y
)
*
1.
/
n
/
n
*
L
*
L
if
d
<
r
*
r
:
s
[
i
,
j
]
=
-
r
+
np
.
sqrt
(
r
*
r
-
d
)
else
:
s
[
i
,
j
]
=
-
r
print
"
\n
::: DATA ::::::::::::::::::::::::::::::
\n
"
print
" [N] {0}
\n
"
.
format
(
n
)
print
" [r] {0}
\n
"
.
format
(
r
)
print
" [Pext] {0}
\n
"
.
format
(
max_pressure
)
print
" [Steps] {0}
\n
"
.
format
(
Ninc
)
print
" [Precision] {0}
\n
"
.
format
(
epsilon
)
bem
=
tamaas
.
BemPolonski
(
s
)
bem
.
setEffectiveModulus
(
Estar
)
file
=
open
(
"hertz-prediction"
,
'w'
)
file
.
write
(
"#pressure
\t
load
\t
computed-load
\t
area_ratio
\t
area
\t
radius
\t
radius-hertz
\t
radius/radius-hertz
\t
p0
\t
p0-hertz
\n
"
)
for
i
in
range
(
0
,
Ninc
):
pressure
+=
dp
bem
.
computeEquilibrium
(
epsilon
,
pressure
)
A
=
tamaas
.
SurfaceStatistics
.
computeContactAreaRatio
(
bem
.
getTractions
())
dumpHertzPrediction
(
file
,
bem
,
pressure
,
r
,
Estar
)
if
A
==
1.0
:
file
.
close
()
break
tamaas
.
dumpTimes
()
################################################################
import
sys
import
argparse
import
numpy
as
np
main
(
sys
.
argv
)
Event Timeline
Log In to Comment