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compute_impulse.cc
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/**
* @file compute_impulse.cc
*
* @author Guillaume Anciaux <guillaume.anciaux@epfl.ch>
*
* @date Wed Jul 09 21:59:47 2014
*
* @brief This stimulator sets an initial impulse displacement field that will
* generate a wave
*
* @section LICENSE
*
* Copyright (©) 2010-2011 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
* LibMultiScale 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.
*
* LibMultiScale 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 LibMultiScale. If not, see <http://www.gnu.org/licenses/>.
*
*/
/* -------------------------------------------------------------------------- */
#include "compute_impulse.hh"
#include "filter.hh"
#include "lib_continuum.hh"
#include "lib_dd.hh"
#include "lib_md.hh"
#include "lm_common.hh"
#include "ref_point_data.hh"
/* -------------------------------------------------------------------------- */
__BEGIN_LIBMULTISCALE__
ComputeImpulse::ComputeImpulse(const std::string &name)
: ComputeInterface(name) {
impulseType = Impulse::PLANAR;
direction = 0;
for (UInt i = 0; i < 3; ++i) {
center[i] = 0.0;
}
};
/* -------------------------------------------------------------------------- */
ComputeImpulse::~ComputeImpulse() {}
/* -------------------------------------------------------------------------- */
void ComputeImpulse::init() { wave_number = 2 * M_PI / wave_length; }
/* -------------------------------------------------------------------------- */
inline Real ComputeImpulse::computeScaleImpulse(Real d) {
const Real k = wave_number;
const Real res = intensity * sin(k * d) * exp(-k * k / 9 * d * d);
DUMP("impulse computed: " << d << " " << k << " " << intensity << " => "
<< res,
DBG_INFO);
return res;
}
/* -------------------------------------------------------------------------- */
template <>
inline UInt Parser::parse(Impulse::ImpulseType &type, std::stringstream &line,
UInt n_entries) {
std::string name;
UInt nb = strNext(name, line);
if (name == "CIRCULAR")
type = Impulse::CIRCULAR;
else if (name == "PLANAR")
type = Impulse::PLANAR;
else
LM_FATAL("unknown impulse type " << name);
return nb;
}
/* -------------------------------------------------------------------------- */
template <typename Cont> void ComputeImpulse::build(Cont &cont) {
constexpr UInt Dim = Cont::Dim;
this->empty();
this->setDim(Cont::Dim);
for (auto &&at : cont) {
if (impulseType == Impulse::PLANAR) {
Real d = at.position0()[direction] - center[direction];
Real impulse = computeScaleImpulse(d);
for (UInt i = 0; i < Dim; ++i) {
if (i == direction)
this->add(impulse);
else
this->add(0.0);
}
} else if (impulseType == Impulse::CIRCULAR) {
Real vec_dir[Dim];
Real norm_vec_dir = 0;
for (UInt i = 0; i < Dim; ++i) {
Real dist = at.position0()[i] - center[i];
vec_dir[i] = dist;
dist *= dist;
norm_vec_dir += dist;
}
norm_vec_dir = sqrt(norm_vec_dir);
if (norm_vec_dir == 0.)
LM_FATAL("Cannot compute a displacement at the center of the circle");
for (UInt i = 0; i < Dim; ++i)
vec_dir[i] /= norm_vec_dir;
Real d = norm_vec_dir - radius;
Real impulse = computeScaleImpulse(d);
for (UInt i = 0; i < Dim; ++i) {
this->add(impulse * vec_dir[i]);
}
}
}
this->name_computed.clear();
this->name_computed.push_back("impulse");
}
/* -------------------------------------------------------------------------- */
/* LMDESC IMPULSE
This stimulator sets an initial impulse displacement field that will generate
a wave. It can generate planar or circular waves:\\
\begin{itemize}
\item Planar: $u(\vec{X}) += I \cdot sin\left(k d \right) exp\left(-\frac{(k
d)^2}{9} \right) \vec{e_i}$,
with $I$ the intensity, $i$ the chosen direction and
$k = 2\pi/LWAVE$ and $d = \vec{X}_i-\vec{C}_i$ as defined with the parameters
(see below).
\item Circular:
$u(X) += I \cdot sin\left(k (d - R) \right) exp\left(-\frac{(k (d - R))^2}{9}
\right) \frac{\vec{X} - \vec{C}}{d}$,
with $I$ the intensity,
$k = 2\pi/LWAVE$ and $d = \mid\mid \vec{X} - \vec{C} \mid\mid$ and $R$ a
radius as defined with the parameters (see below).
\end{itemize}
*/
/* LMEXAMPLE COMPUTE impulse IMPULSE INPUT central_md LWAVE WaveLength*r0
* DIRECTION 0 INTENSITY 1.1e-3 ONESHOT 0 */
void ComputeImpulse::declareParams() {
/* LMKEYWORD LWAVE
Set the wavelength of the wave to be generated
*/
this->parseKeyword("LWAVE", wave_length);
/* LMKEYWORD DIRECTION
It can be 0,1 or 2 to specify X, Y or Z direction for planar waves
*/
this->parseKeyword("DIRECTION", direction, 0u);
/* LMKEYWORD RADIUS
Radius to be used to generate the impulse
*/
this->parseKeyword("RADIUS", radius, 0.);
/* LMKEYWORD INTENSITY
Intensity of the displacement
*/
this->parseKeyword("INTENSITY", intensity);
/* LMKEYWORD CENTER
center of the impulse to be injected
*/
this->parseVectorKeyword("CENTER", spatial_dimension, center,
VEC_DEFAULTS(0., 0., 0.));
/* LMKEYWORD TYPE
Flag to specify the type of impulse.
It can be either CIRCULAR or PLANAR.
Self-explanatory examples are:\\
COMPUTE impulse-planar IMPULSE INPUT md LWAVE L0/10 DIRECTION 0 INTENSITY
1e-3 CENTER 0 0 \\
\includegraphics[scale=.5]{images/planar-impulse} \\
COMPUTE impulse-circular IMPULSE INPUT md LWAVE L0/10 TYPE CIRCULAR RADIUS
L0/4 INTENSITY 1e-3 CENTER 0 0 \\
\includegraphics[scale=.5]{images/radial-impulse}
*/
this->parseKeyword("TYPE", impulseType, Impulse::PLANAR);
}
/* -------------------------------------------------------------------------- */
DECLARE_COMPUTE_MAKE_CALL(ComputeImpulse);
__END_LIBMULTISCALE__

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