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ntrf_friction_regularized_coulomb.cc
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ntrf_friction_regularized_coulomb.cc
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/**
* @file ntrf_friction_regularized_coulomb.cc
* @author David Kammer <david.kammer@epfl.ch>
* @date Thu May 23 16:34:58 2013
*
* @brief implementation of ntrf friction regularized coulomb
*
* @section LICENSE
*
* Copyright (©) 2010-2011 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
* Akantu 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.
*
* Akantu 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 Akantu. If not, see <http://www.gnu.org/licenses/>.
*
*/
/* -------------------------------------------------------------------------- */
// simtools
#include "ntrf_friction_regularized_coulomb.hh"
__BEGIN_SIMTOOLS__
/* -------------------------------------------------------------------------- */
NTRFFrictionRegularizedCoulomb::NTRFFrictionRegularizedCoulomb(NTRFContact & contact,
const FrictionID & id,
const MemoryID & memory_id) :
NTRFFrictionCoulomb(contact,id,memory_id),
regularization_on(false),
t_star(0,1,0.,id+":t_star",0.,"t_star") {
AKANTU_DEBUG_IN();
NTRFFrictionCoulomb::registerSyncronizedArray(this->t_star);
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::computeFrictionalContactPressure() {
AKANTU_DEBUG_IN();
if (!this->regularization_on)
NTRFFrictionCoulomb::computeFrictionalContactPressure();
else {
SolidMechanicsModel & model = this->contact.getModel();
UInt dim = model.getSpatialDimension();
Real delta_t = model.getTimeStep();
UInt nb_contact_nodes = this->contact.getNbContactNodes();
// get contact arrays
const SyncronizedArray<bool> & is_in_contact = this->contact.getIsInContact();
Real * contact_pressure = this->contact.getContactPressure().storage();
for (UInt n=0; n<nb_contact_nodes; ++n) {
// node pair is NOT in contact
if (!is_in_contact(n))
this->frictional_contact_pressure(n) = 0.;
// if t_star is too small compute like Coulomb friction (without regularization)
else if (Math::are_float_equal(this->t_star(n), 0.)) {
this->frictional_contact_pressure(n) = Math::norm(dim, &(contact_pressure[n*dim]));
}
else {
// compute frictional contact pressure
// backward euler method: first order implicit numerical integration method
// \reg_pres_n+1 = (\reg_pres_n + \delta_t / \t_star * \cur_pres)
// / (1 + \delta_t / \t_star)
Real current_contact_pressure = Math::norm(dim, &(contact_pressure[n*dim]));
Real alpha = delta_t / this->t_star(n);
this->frictional_contact_pressure(n) += alpha * current_contact_pressure;
this->frictional_contact_pressure(n) /= 1 + alpha;
}
}
}
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::registerSyncronizedArray(SyncronizedArrayBase & array) {
AKANTU_DEBUG_IN();
this->t_star.registerDependingArray(array);
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::dumpRestart(const std::string & file_name) const {
AKANTU_DEBUG_IN();
this->t_star.dumpRestartFile(file_name);
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::readRestart(const std::string & file_name) {
AKANTU_DEBUG_IN();
this->t_star.readRestartFile(file_name);
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::setTStar(Real tstar) {
AKANTU_DEBUG_IN();
NTRFFriction::setInternalArray(this->t_star, tstar);
this->regularization_on = true;
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::setTStar(UInt node, Real tstar) {
AKANTU_DEBUG_IN();
NTRFFriction::setInternalArray(this->t_star, node, tstar);
this->regularization_on = true;
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::printself(std::ostream & stream, int indent) const {
AKANTU_DEBUG_IN();
std::string space;
for(Int i = 0; i < indent; i++, space += AKANTU_INDENT);
stream << space << "NTRFFrictionRegularizedCoulomb [" << std::endl;
stream << space << "Regularization On: " << this->regularization_on << std::endl;
stream << space << this->t_star << std::endl;
stream << space << "]" << std::endl;
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::setToSteadyState() {
AKANTU_DEBUG_IN();
NTRFFrictionCoulomb::computeFrictionalContactPressure();
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void NTRFFrictionRegularizedCoulomb::addDumpField(const std::string & field_id) {
AKANTU_DEBUG_IN();
#ifdef AKANTU_USE_IOHELPER
// const SyncronizedArray<UInt> * nodal_filter = &(this->contact.getSlaves());
if(field_id == "t_star") {
this->contact.addDumpFieldExternal(field_id,
new DumperIOHelper::NodalField<Real>(this->t_star.getArray()));
}
else {
NTRFFrictionCoulomb::addDumpField(field_id);
}
#endif
AKANTU_DEBUG_OUT();
}
__END_SIMTOOLS__

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