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material_FE2.cc
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Mon, Nov 25, 01:33

material_FE2.cc
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/**
* @file material_FE2.cc
*
* @author Aurelia Isabel Cuba Ramos <aurelia.cubaramos@epfl.ch>
*
* @brief Material for multi-scale simulations. It stores an
* underlying RVE on each integration point of the material.
*
* @section LICENSE
*
* Copyright (©) 2010-2012, 2014 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
*/
/* -------------------------------------------------------------------------- */
#include "material_FE2.hh"
__BEGIN_AKANTU__
/* -------------------------------------------------------------------------- */
template<UInt spatial_dimension>
MaterialFE2<spatial_dimension>::MaterialFE2(SolidMechanicsModel & model,
const ID & id) :
Material(model, id),
C("material_stiffness", *this)
{
AKANTU_DEBUG_IN();
this->C.initialize(voigt_h::size * voigt_h::size);
this->initialize();
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template<UInt spatial_dimension>
MaterialFE2<spatial_dimension>::~MaterialFE2() {
for (UInt i = 0; i < RVEs.size(); ++i) {
delete RVEs[i];
}
}
/* -------------------------------------------------------------------------- */
template<UInt dim>
void MaterialFE2<dim>::initialize() {
this->registerParam("element_type" ,el_type, _triangle_3 , _pat_parsable | _pat_modifiable, "element type in RVE mesh" );
this->registerParam("mesh_file" ,mesh_file , _pat_parsable | _pat_modifiable, "the mesh file for the RVE");
}
/* -------------------------------------------------------------------------- */
template<UInt spatial_dimension>
void MaterialFE2<spatial_dimension>::initMaterial() {
Material::initMaterial();
/// compute the number of integration points in this material and resize the RVE vector
UInt nb_integration_points = this->element_filter(this->el_type, _not_ghost).getSize()
* this->fem->getNbIntegrationPoints(this->el_type);
RVEs.resize(nb_integration_points);
/// create a SolidMechanicsModel on each integration point of the material
std::vector<SolidMechanicsModelRVE *>::iterator RVE_it = RVEs.begin();
Array<Real>::matrix_iterator C_it =
this->C(this->el_type).begin(voigt_h::size, voigt_h::size);
for (UInt i = 1; i < nb_integration_points+1; ++RVE_it, ++i, ++C_it) {
Mesh mesh(spatial_dimension, "RVE_mesh", i);
mesh.read(mesh_file);
*RVE_it = new SolidMechanicsModelRVE(mesh, true, _all_dimensions, "SMM_RVE", i);
(*RVE_it)->initFull();
/// compute intial stiffness of the RVE
(*RVE_it)->homogenizeStiffness(*C_it);
}
}
/* -------------------------------------------------------------------------- */
template<UInt spatial_dimension>
void MaterialFE2<spatial_dimension>::computeStress(ElementType el_type,
GhostType ghost_type) {
// Wikipedia convention:
// 2*eps_ij (i!=j) = voigt_eps_I
// http://en.wikipedia.org/wiki/Voigt_notation
AKANTU_DEBUG_IN();
Array<Real>::const_matrix_iterator C_it = this->C(el_type, ghost_type).begin(voigt_h::size,
voigt_h::size);
// create vectors to store stress and strain in Voigt notation
// for efficient computation of stress
Vector<Real> voigt_strain(voigt_h::size);
Vector<Real> voigt_stress(voigt_h::size);
MATERIAL_STRESS_QUADRATURE_POINT_LOOP_BEGIN(el_type, ghost_type);
const Matrix<Real> & C_mat = *C_it;
/// copy strains in Voigt notation
for(UInt I = 0; I < voigt_h::size; ++I) {
/// copy stress in
Real voigt_factor = voigt_h::factors[I];
UInt i = voigt_h::vec[I][0];
UInt j = voigt_h::vec[I][1];
voigt_strain(I) = voigt_factor * (grad_u(i, j) + grad_u(j, i)) / 2.;
}
// compute stresses in Voigt notation
voigt_stress.mul<false>(C_mat, voigt_strain);
/// copy stresses back in full vectorised notation
for(UInt I = 0; I < voigt_h::size; ++I) {
UInt i = voigt_h::vec[I][0];
UInt j = voigt_h::vec[I][1];
sigma(i, j) = sigma(j, i) = voigt_stress(I);
}
++C_it;
MATERIAL_STRESS_QUADRATURE_POINT_LOOP_END;
}
/* -------------------------------------------------------------------------- */
template<UInt spatial_dimension>
void MaterialFE2<spatial_dimension>::computeTangentModuli(const ElementType & el_type,
Array<Real> & tangent_matrix,
GhostType ghost_type) {
AKANTU_DEBUG_IN();
Array<Real>::const_matrix_iterator C_it = this->C(el_type, ghost_type).begin(voigt_h::size,
voigt_h::size);
MATERIAL_TANGENT_QUADRATURE_POINT_LOOP_BEGIN(tangent_matrix);
tangent.copy(*C_it);
++C_it;
MATERIAL_TANGENT_QUADRATURE_POINT_LOOP_END;
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template<UInt spatial_dimension>
void MaterialFE2<spatial_dimension>::advanceASR(const Matrix<Real> & prestrain) {
std::vector<SolidMechanicsModelRVE *>::iterator RVE_it = RVEs.begin();
std::vector<SolidMechanicsModelRVE *>::iterator RVE_end = RVEs.end();
Array<Real>::matrix_iterator C_it =
this->C(this->el_type).begin(voigt_h::size, voigt_h::size);
Array<Real>::matrix_iterator gradu_it =
this->gradu(this->el_type).begin(spatial_dimension, spatial_dimension);
Array<Real>::matrix_iterator eigen_gradu_it =
this->eigengradu(this->el_type).begin(spatial_dimension, spatial_dimension);
for (; RVE_it != RVE_end; ++RVE_it, ++C_it, ++gradu_it, ++eigen_gradu_it) {
/// apply boundary conditions based on the current macroscopic displ. gradient
(*RVE_it)->applyBoundaryConditions(*gradu_it);
/// advance the ASR in every RVE
(*RVE_it)->advanceASR(prestrain);
/// compute the new effective stiffness of the RVE
(*RVE_it)->homogenizeStiffness(*C_it);
/// compute the average eigen_grad_u
(*RVE_it)->homogenizeEigenGradU(*eigen_gradu_it);
}
}
INSTANTIATE_MATERIAL(MaterialFE2);
__END_AKANTU__

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