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tamaas/src/model/elasto_plastic/isotropic_hardening.cpp
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isotropic_hardening.cpp
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/**
* @file
*
* @author Lucas Frérot <lucas.frerot@epfl.ch>
*
* @section LICENSE
*
* Copyright (©) 2017 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 "isotropic_hardening.hh"
#include "influence.hh"
/* -------------------------------------------------------------------------- */
__BEGIN_TAMAAS__
/* -------------------------------------------------------------------------- */
template <model_type type>
IsotropicHardening<type>::IsotropicHardening(Model* model, Real sigma_0, Real h)
: model(model), sigma_0(sigma_0), h(h) {
plastic_strain.setNbComponents(trait::components * trait::components);
cumulated_plastic_strain.setNbComponents(1);
plastic_strain.resize(model->getDiscretization());
cumulated_plastic_strain.resize(model->getDiscretization());
}
/* -------------------------------------------------------------------------- */
template <>
void IsotropicHardening<model_type::volume_2d>::applyTangentIncrement(
Grid<Real, dim>& output, const Grid<Real, dim>& input,
const Grid<Real, dim>& strain,
const Grid<Real, dim>& strain_increment) const {
const influence::ElasticHelper<dim> elasticity(
this->model->getShearModulus(), this->model->getPoissonRatio());
using pmatrix = MatrixProxy<Real, dim, dim>;
using cpmatrix = MatrixProxy<const Real, dim, dim>;
Loop::loop(
[&elasticity, this](pmatrix out, cpmatrix in, cpmatrix epsilon,
cpmatrix delta_epsilon, cpmatrix ep, const Real& p) {
auto sigma_tr = elasticity(epsilon - ep + delta_epsilon);
decltype(sigma_tr) dev;
dev.deviatoric(sigma_tr, 3);
auto von_mises = std::sqrt(1.5) * dev.l2norm();
if (von_mises - hardening(p) > 0) {
Real dp = (von_mises - hardening(p)) / (3 * elasticity.mu + h);
// Applying tangent from Bonnet & Frangi, p.175
const Real beta = 3 * elasticity.mu * dp / von_mises;
const Real gamma = 3 * elasticity.mu / (3 * elasticity.mu + this->h);
const Real dot = dev.dot(in);
dev *= 3 * elasticity.mu * (gamma - beta) * dot /
(von_mises * von_mises);
out.deviatoric(in);
out *= 2 * elasticity.mu * beta;
out += dev;
} else
out = 0;
},
range<pmatrix>(output), range<cpmatrix>(input), range<cpmatrix>(strain),
range<cpmatrix>(strain_increment), range<cpmatrix>(this->plastic_strain),
this->cumulated_plastic_strain);
}
/* -------------------------------------------------------------------------- */
/* Template instanciation */
/* -------------------------------------------------------------------------- */
template class IsotropicHardening<model_type::volume_2d>;
__END_TAMAAS__
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