Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F87402224
bem_gigi.cpp
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, Oct 12, 11:52
Size
8 KB
Mime Type
text/x-c
Expires
Mon, Oct 14, 11:52 (1 d, 23 h)
Engine
blob
Format
Raw Data
Handle
21500514
Attached To
rTAMAAS tamaas
bem_gigi.cpp
View Options
/**
*
* @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/>.
*
*/
/* -------------------------------------------------------------------------- */
#include <vector>
#include "surface.hh"
#include "bem_gigi.hh"
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <sstream>
#include <cmath>
/* -------------------------------------------------------------------------- */
#define TIMER
#include "surface_timer.hh"
/* -------------------------------------------------------------------------- */
__BEGIN_TAMAAS__
Real
BemGigi
::
computeEquilibrium
(
Real
epsilon
,
Real
mean_displacement
)
{
this
->
computeSpectralInfluenceOverDisplacement
();
Real
Rold
=
1.
;
Real
f
=
1e300
;
this
->
search_direction
=
0.
;
this
->
true_displacements
=
0
;
this
->
true_displacements
=
mean_displacement
;
this
->
computeGaps
();
this
->
optimizeToMeanDisplacement
(
mean_displacement
);
this
->
computeGaps
();
convergence_iterations
.
clear
();
nb_iterations
=
0
;
max_iterations
=
50
;
Real
R
=
0
;
while
(
f
>
epsilon
&&
nb_iterations
++
<
max_iterations
)
{
this
->
computeGaps
();
this
->
functional
->
computeGradFU
();
this
->
updateSearchDirection
(
R
/
Rold
);
Rold
=
R
;
Real
alpha
=
this
->
computeOptimalStep
();
std
::
cout
<<
"alpha vaut "
<<
alpha
<<
std
::
endl
;
this
->
old_displacements
=
this
->
true_displacements
;
this
->
updateDisplacements
(
alpha
);
this
->
computeGaps
();
this
->
optimizeToMeanDisplacement
(
mean_displacement
);
//espace admissible
this
->
computeGaps
();
this
->
computePressures
(
mean_displacement
);
f
=
computeStoppingCriterion
();
}
this
->
computePressures
(
mean_displacement
);
return
f
;
}
/* -------------------------------------------------------------------------- */
Real
BemGigi
::
computeStoppingCriterion
()
{
Real
rho
=
this
->
functional
->
getParameter
(
"rho"
);
Real
surface_energy
=
this
->
functional
->
getParameter
(
"surface_energy"
);
Real
crit
=
0.
;
//Real disp_norm = 0.;
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
//#pragma omp parallel for reduction(+:crit, disp_norm)
#pragma omp parallel for reduction(+:crit)
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
crit
+=
std
::
abs
(
this
->
gap
(
i
)
*
(
this
->
surface_tractions
(
i
)
+
surface_energy
/
rho
*
exp
(
-
(
gap
(
i
))
/
rho
)));
}
return
crit
;
}
/* -------------------------------------------------------------------------- */
/* -------------------------------------------------------------------------- */
void
BemGigi
::
optimizeToMeanDisplacement
(
Real
imposed_mean
)
{
Real
target_value
=
imposed_mean
-
SurfaceStatistics
::
computeAverage
(
surface
,
0
);
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
// Initial guesses for upper and lower bound
Real
step_min
=
-
10
;
Real
step_max
=
10
;
// Gaps for upper and lower bound
Real
gap_min
=
positiveGapAverage
(
step_min
);
Real
gap_max
=
positiveGapAverage
(
step_max
);
UInt
max_expansion
=
8
;
// Expand bounds if necessary
for
(
UInt
i
=
0
;
gap_max
<
target_value
&&
i
<
max_expansion
;
i
++
,
step_max
*=
10
)
gap_max
=
positiveGapAverage
(
step_max
);
for
(
UInt
i
=
0
;
gap_min
>
target_value
&&
i
<
max_expansion
;
i
++
,
step_min
*=
10
)
gap_min
=
positiveGapAverage
(
step_min
);
Real
g
=
0.
;
Real
epsilon
=
1e-12
;
Real
step
=
0
;
while
(
fabs
(
g
-
target_value
)
>
epsilon
)
{
step
=
(
step_min
+
step_max
)
/
2.
;
g
=
positiveGapAverage
(
step
);
if
(
g
>
target_value
)
step_max
=
step
;
else
if
(
g
<
target_value
)
step_min
=
step
;
else
{
step_max
=
step
;
step_min
=
step
;
}
}
step
=
(
step_min
+
step_max
)
/
2.
;
#pragma omp parallel for
for
(
UInt
i
=
0
;
i
<
size
;
i
++
)
{
gap
(
i
)
+=
step
;
if
(
gap
(
i
)
<
0
)
gap
(
i
)
=
0
;
true_displacements
(
i
)
=
gap
(
i
)
+
surface
(
i
);
}
}
/* -------------------------------------------------------------------------- */
Real
BemGigi
::
positiveGapAverage
(
Real
shift
)
{
UInt
n
=
surface
.
size
();
Real
res
=
0
;
#pragma omp parallel for reduction(+: res)
for
(
UInt
i
=
0
;
i
<
n
*
n
;
i
++
)
{
Real
shifted_gap
=
gap
(
i
)
+
shift
;
res
+=
shifted_gap
*
(
shifted_gap
>
0
);
}
return
res
/
(
n
*
n
);
}
/* -------------------------------------------------------------------------- */
void
BemGigi
::
updateSearchDirection
(
Real
factor
)
{
STARTTIMER
(
"updateSearchDirection"
);
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
const
Surface
<
Real
>
&
gradF
=
this
->
functional
->
getGradF
();
#pragma omp parallel for
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
this
->
search_direction
(
i
)
=
gradF
(
i
);
}
STOPTIMER
(
"updateSearchDirection"
);
}
/* -------------------------------------------------------------------------- */
Real
BemGigi
::
computeOptimalStep
()
{
STARTTIMER
(
"computeOptimalStep"
);
this
->
applyInverseInfluenceFunctions
(
search_direction
,
projected_direction
);
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
const
Surface
<
Real
>
&
gradF
=
this
->
functional
->
getGradF
();
Real
numerator
=
0.
,
denominator
=
0.
;
#pragma omp parallel for reduction(+: numerator, denominator)
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
numerator
+=
gradF
(
i
)
*
search_direction
(
i
);
denominator
+=
projected_direction
(
i
)
*
search_direction
(
i
);
}
Real
alpha
=
numerator
/
denominator
;
STOPTIMER
(
"computeOptimalStep"
);
return
alpha
;
}
/* -------------------------------------------------------------------------- */
Real
BemGigi
::
computeTau
()
{
return
computeOptimalStep
();
}
/* -------------------------------------------------------------------------- */
void
BemGigi
::
updateDisplacements
(
Real
alpha
)
{
STARTTIMER
(
"updateDisplacements"
);
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
#pragma omp parallel for
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
this
->
true_displacements
(
i
)
-=
alpha
*
this
->
search_direction
(
i
);
}
STOPTIMER
(
"updateDisplacements"
);
}
/* -------------------------------------------------------------------------- */
void
BemGigi
::
emptyOverlap
()
{
STARTTIMER
(
"emptyoverlap"
);
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
#pragma omp parallel for
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
if
(
gap
(
i
)
<
0
)
this
->
true_displacements
(
i
)
=
this
->
surface
(
i
);
}
STOPTIMER
(
"emptyoverlap"
);
}
/* -------------------------------------------------------------------------- */
void
BemGigi
::
enforceMeanDisplacement
(
Real
mean_displacement
)
{
STARTTIMER
(
"enforceMeanDisplacement"
);
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
Real
moyenne_surface
=
SurfaceStatistics
::
computeAverage
(
this
->
surface
,
0
);
Real
average
=
SurfaceStatistics
::
computeAverage
(
this
->
true_displacements
,
0
);
Real
factor
=
(
mean_displacement
-
moyenne_surface
)
/
(
average
-
moyenne_surface
);
#pragma omp parallel for
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
this
->
true_displacements
(
i
)
=
factor
*
(
this
->
true_displacements
(
i
)
-
this
->
surface
(
i
))
+
this
->
surface
(
i
);
}
STOPTIMER
(
"enforceMeanDisplacement"
);
}
/* -------------------------------------------------------------------------- */
void
BemGigi
::
computePressures
(
Real
mean_displacement
)
{
this
->
computeTractionsFromDisplacements
();
UInt
n
=
surface
.
size
();
UInt
size
=
n
*
n
;
Real
rho
=
this
->
functional
->
getParameter
(
"rho"
);
Real
surface_energy
=
this
->
functional
->
getParameter
(
"surface_energy"
);
Real
mini
=
3000
;
for
(
UInt
i
=
0
;
i
<
size
;
++
i
)
{
if
(
gap
(
i
)
<
rho
){
if
(
this
->
surface_tractions
(
i
)
+
surface_energy
/
rho
<
mini
)
mini
=
this
->
surface_tractions
(
i
)
+
surface_energy
/
rho
;
}
else
{
if
(
this
->
surface_tractions
(
i
)
<
mini
)
mini
=
this
->
surface_tractions
(
i
)
;}
}
this
->
surface_tractions
-=
mini
;
}
__END_TAMAAS__
Event Timeline
Log In to Comment