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material_damage_iterative.cc
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rAKA akantu
material_damage_iterative.cc
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/**
* @file material_damage_iterative.cc
*
* @author Aurelia Isabel Cuba Ramos <aurelia.cubaramos@epfl.ch>
*
*
* @brief Specialization of the class material damage to damage only one gauss
* point at a time and propagate damage in a linear way. Max principal stress
* criterion is used as a failure criterion.
*
* @section LICENSE
*
* Copyright (©) 2010-2012, 2014 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
*/
/* -------------------------------------------------------------------------- */
#include "material_damage_iterative.hh"
#include "solid_mechanics_model_RVE.hh"
#include "communicator.hh"
#include "data_accessor.hh"
/* -------------------------------------------------------------------------- */
namespace akantu {
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
MaterialDamageIterative<spatial_dimension>::MaterialDamageIterative(
SolidMechanicsModel & model, const ID & id)
: MaterialDamage<spatial_dimension>(model, id),
Sc("Sc", *this), reduction_step("damage_step", *this),
equivalent_stress("equivalent_stress", *this), max_reductions(0),
norm_max_equivalent_stress(0) {
AKANTU_DEBUG_IN();
this->registerParam("Sc", Sc, _pat_parsable, "critical stress threshold");
this->registerParam("prescribed_dam", prescribed_dam, 0.1,
_pat_parsable | _pat_modifiable, "prescribed damage");
this->registerParam(
"dam_threshold", dam_threshold, 0.8, _pat_parsable | _pat_modifiable,
"damage threshold at which damage damage will be set to 1");
this->registerParam(
"dam_tolerance", dam_tolerance, 0.01, _pat_parsable | _pat_modifiable,
"damage tolerance to decide if quadrature point will be damageed");
this->registerParam("max_damage", max_damage, 0.99999,
_pat_parsable | _pat_modifiable, "maximum damage value");
this->registerParam("max_reductions", max_reductions, UInt(10),
_pat_parsable | _pat_modifiable, "max reductions");
this->use_previous_stress = true;
this->use_previous_gradu = true;
this->Sc.initialize(1);
this->equivalent_stress.initialize(1);
this->reduction_step.initialize(1);
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
void MaterialDamageIterative<spatial_dimension>::
computeNormalizedEquivalentStress(const Array<Real> & grad_u,
ElementType el_type,
GhostType ghost_type) {
AKANTU_DEBUG_IN();
/// Vector to store eigenvalues of current stress tensor
Vector<Real> eigenvalues(spatial_dimension);
Array<Real>::const_iterator<Real> Sc_it = Sc(el_type, ghost_type).begin();
Array<Real>::iterator<Real> equivalent_stress_it =
equivalent_stress(el_type, ghost_type).begin();
Array<Real>::const_matrix_iterator grad_u_it =
grad_u.begin(spatial_dimension, spatial_dimension);
Array<Real>::const_matrix_iterator grad_u_end =
grad_u.end(spatial_dimension, spatial_dimension);
Real * dam = this->damage(el_type, ghost_type).storage();
Matrix<Real> sigma(spatial_dimension, spatial_dimension);
for (; grad_u_it != grad_u_end; ++grad_u_it) {
sigma.clear();
MaterialElastic<spatial_dimension>::computeStressOnQuad(*grad_u_it, sigma,
0.);
computeDamageAndStressOnQuad(sigma, *dam);
/// compute eigenvalues
sigma.eig(eigenvalues);
/// find max eigenvalue and normalize by tensile strength
*equivalent_stress_it =
*(std::max_element(eigenvalues.storage(),
eigenvalues.storage() + spatial_dimension)) /
*(Sc_it);
++Sc_it;
++equivalent_stress_it;
++dam;
}
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
void MaterialDamageIterative<spatial_dimension>::computeAllStresses(
GhostType ghost_type) {
AKANTU_DEBUG_IN();
/// reset normalized maximum equivalent stress
if (ghost_type == _not_ghost)
norm_max_equivalent_stress = 0;
MaterialDamage<spatial_dimension>::computeAllStresses(ghost_type);
/// find global Gauss point with highest stress
auto rve_model =
dynamic_cast<SolidMechanicsModelRVE *>(&this->model);
if (rve_model == NULL) {
/// is no RVE model
const auto & comm = this->model.getMesh().getCommunicator();
comm.allReduce(norm_max_equivalent_stress, SynchronizerOperation::_max);
}
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
void MaterialDamageIterative<spatial_dimension>::
findMaxNormalizedEquivalentStress(ElementType el_type,
GhostType ghost_type) {
AKANTU_DEBUG_IN();
if (ghost_type == _not_ghost) {
// const Array<Real> & e_stress = equivalent_stress(el_type);
// if (e_stress.begin() != e_stress.end() ) {
// Array<Real>::const_iterator<Real> equivalent_stress_it_max =
// std::max_element(e_stress.begin(),e_stress.end());
// /// check if max equivalent stress for this element type is greater
// than the current norm_max_eq_stress
// if (*equivalent_stress_it_max > norm_max_equivalent_stress)
// norm_max_equivalent_stress = *equivalent_stress_it_max;
// }
const Array<Real> & e_stress = equivalent_stress(el_type);
Array<Real>::const_iterator<Real> equivalent_stress_it = e_stress.begin();
Array<Real>::const_iterator<Real> equivalent_stress_end = e_stress.end();
Array<Real> & dam = this->damage(el_type);
Array<Real>::iterator<Real> dam_it = dam.begin();
for (; equivalent_stress_it != equivalent_stress_end;
++equivalent_stress_it, ++dam_it) {
/// check if max equivalent stress for this element type is greater than
/// the current norm_max_eq_stress and if the element is not already fully
/// damaged
if (*equivalent_stress_it > norm_max_equivalent_stress &&
*dam_it < max_damage) {
norm_max_equivalent_stress = *equivalent_stress_it;
}
}
}
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
void MaterialDamageIterative<spatial_dimension>::computeStress(
ElementType el_type, GhostType ghost_type) {
AKANTU_DEBUG_IN();
MaterialDamage<spatial_dimension>::computeStress(el_type, ghost_type);
Real * dam = this->damage(el_type, ghost_type).storage();
MATERIAL_STRESS_QUADRATURE_POINT_LOOP_BEGIN(el_type, ghost_type);
computeDamageAndStressOnQuad(sigma, *dam);
++dam;
MATERIAL_STRESS_QUADRATURE_POINT_LOOP_END;
computeNormalizedEquivalentStress(this->gradu(el_type, ghost_type), el_type,
ghost_type);
norm_max_equivalent_stress = 0;
findMaxNormalizedEquivalentStress(el_type, ghost_type);
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
UInt MaterialDamageIterative<spatial_dimension>::updateDamage() {
UInt nb_damaged_elements = 0;
AKANTU_DEBUG_ASSERT(prescribed_dam > 0.,
"Your prescribed damage must be greater than zero");
if (norm_max_equivalent_stress >= 1.) {
AKANTU_DEBUG_IN();
/// update the damage only on non-ghosts elements! Doesn't make sense to
/// update on ghost.
GhostType ghost_type = _not_ghost;
;
Mesh::type_iterator it = this->model.getFEEngine().getMesh().firstType(
spatial_dimension, ghost_type);
Mesh::type_iterator last_type =
this->model.getFEEngine().getMesh().lastType(spatial_dimension,
ghost_type);
for (; it != last_type; ++it) {
ElementType el_type = *it;
const Array<Real> & e_stress = equivalent_stress(el_type);
Array<Real>::const_iterator<Real> equivalent_stress_it = e_stress.begin();
Array<Real>::const_iterator<Real> equivalent_stress_end = e_stress.end();
Array<Real> & dam = this->damage(el_type);
Array<Real>::iterator<Real> dam_it = dam.begin();
Array<UInt>::scalar_iterator reduction_it =
this->reduction_step(el_type, ghost_type).begin();
for (; equivalent_stress_it != equivalent_stress_end;
++equivalent_stress_it, ++dam_it, ++reduction_it) {
/// check if damage occurs
if (*equivalent_stress_it >=
(1 - dam_tolerance) * norm_max_equivalent_stress) {
/// check if this element can still be damaged
if (*reduction_it == this->max_reductions)
continue;
*reduction_it += 1;
if (*reduction_it == this->max_reductions) {
*dam_it = max_damage;
} else {
*dam_it += prescribed_dam;
}
nb_damaged_elements += 1;
}
}
}
}
auto * rve_model =
dynamic_cast<SolidMechanicsModelRVE *>(&this->model);
if (rve_model == NULL) {
const auto & comm = this->model.getMesh().getCommunicator();
comm.allReduce(nb_damaged_elements, SynchronizerOperation::_sum);
}
AKANTU_DEBUG_OUT();
return nb_damaged_elements;
}
/* -------------------------------------------------------------------------- */
template <UInt spatial_dimension>
void MaterialDamageIterative<spatial_dimension>::updateEnergiesAfterDamage(
ElementType el_type, GhostType ghost_type) {
MaterialDamage<spatial_dimension>::updateEnergies(el_type, ghost_type);
}
/* -------------------------------------------------------------------------- */
INSTANTIATE_MATERIAL(damage_iterative, MaterialDamageIterative);
} // namespace akantu
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