mpi2

projection_finite_strain.cc
View Options

			/**
			* @file projection_finite_strain.cc
			*
			* @author Till Junge <till.junge@altermail.ch>
			*
			* @date 05 Dec 2017
			*
			* @brief implementation of standard finite strain projection operator
			*
			* Copyright © 2017 Till Junge
			*
			* µSpectre is free software; you can redistribute it and/or
			* modify it under the terms of the GNU General Public License as
			* published by the Free Software Foundation, either version 3, or (at
			* your option) any later version.
			*
			* µSpectre 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
			* General Public License for more details.
			*
			* You should have received a copy of the GNU General Public License
			* along with GNU Emacs; see the file COPYING. If not, write to the
			* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
			* Boston, MA 02111-1307, USA.
			*/

			#include "fft/projection_finite_strain.hh"
			#include "fft/fftw_engine.hh"
			#include "fft/fft_utils.hh"
			#include "common/field_map.hh"
			#include "common/tensor_algebra.hh"
			#include "common/iterators.hh"

			#include "Eigen/Dense"

			namespace muSpectre {

			/* ---------------------------------------------------------------------- */
			template <Dim_t DimS, Dim_t DimM>
			ProjectionFiniteStrain<DimS, DimM>::
			ProjectionFiniteStrain(FFT_Engine_ptr engine)
			:Parent{std::move(engine), Formulation::finite_strain}
			{}

			/* ---------------------------------------------------------------------- */
			template <Dim_t DimS, Dim_t DimM>
			void ProjectionFiniteStrain<DimS, DimM>::
			initialise(FFT_PlanFlags flags) {
			Parent::initialise(flags);
			FFT_freqs<DimS> fft_freqs(this->fft_engine->get_resolutions(),
			this->fft_engine->get_lengths());
			for (auto && tup: akantu::zip(*this->fft_engine, this->Ghat)) {
			const auto & ccoord = std::get<0> (tup);
			auto & G = std::get<1>(tup);
			auto xi = fft_freqs.get_unit_xi(ccoord);
			//! this is simplifiable using Curnier's Méthodes numériques, 6.69(c)
			G = Matrices::outer_under(Matrices::I2<DimM>(), xi*xi.transpose());
			// The commented block below corresponds to the original
			// definition of the operator in de Geus et
			// al. (https://doi.org/10.1016/j.cma.2016.12.032). However,
			// they use a bizarre definition of the double contraction
			// between fourth-order and second-order tensors that has a
			// built-in transpose operation (i.e., C = A:B <-> AᵢⱼₖₗBₗₖ =
			// Cᵢⱼ , note the inverted ₗₖ instead of ₖₗ), here, we define
			// the double contraction without the transposition. As a
			// result, the Projection operator produces the transpose of de
			// Geus's

			// for (Dim_t im = 0; im < DimS; ++im) {
			// for (Dim_t j = 0; j < DimS; ++j) {
			// for (Dim_t l = 0; l < DimS; ++l) {
			// get(G, im, j, l, im) = xi(j)*xi(l);
			// }
			// }
			// }
			}
			this->Ghat[0].setZero();
			}

			template class ProjectionFiniteStrain<twoD, twoD>;
			template class ProjectionFiniteStrain<threeD, threeD>;
			} // muSpectre

muSpectre/src/fft/projection_finite_strain.ccdecf9cec7830feat/mpi2

projection_finite_strain.ccView Options

muSpectre/src/fft/projection_finite_strain.cc
decf9cec7830feat/mpi2

projection_finite_strain.cc
View Options