PerezFougetSubstepperMarkII.h

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/* ---------------------------------------------------------------------
 *                                       _
 *  _ __ ___   __ _ _ __ _ __ ___   ___ | |_
 * | '_ ` _ \ / _` | '__| '_ ` _ \ / _ \| __|
 * | | | | | | (_| | |  | | | | | | (_) | |_
 * |_| |_| |_|\__,_|_|  |_| |_| |_|\___/ \__|
 *
 * Unit of Strength of Materials and Structural Analysis
 * University of Innsbruck,
 * 2020 - today
 *
 * festigkeitslehre@uibk.ac.at
 *
 * Matthias Neuner matthias.neuner@uibk.ac.at
 *
 * This file is part of the MAteRialMOdellingToolbox (marmot).
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * The full text of the license can be found in the file LICENSE.md at
 * the top level directory of marmot.
 * ---------------------------------------------------------------------
 */
 
#pragma once
#include "Marmot/MarmotJournal.h"
#include "Marmot/MarmotMath.h"
#include "Marmot/MarmotTypedefs.h"
 
namespace Marmot::NumericalAlgorithms {
 
  template < int nSizeMatTangent >
  class PerezFougetSubstepper {
 
  public:
    typedef Eigen::Matrix< double, nSizeMatTangent, nSizeMatTangent > TangentSizedMatrix;
    PerezFougetSubstepper( double          initialStepSize,
                           double          minimumStepSize,
                           double          scaleUpFactor,
                           double          scaleDownFactor,
                           int             nPassesToIncrease,
                           const Matrix6d& Cel );
 
    bool isFinished();
 
    double getNextSubstep();
 
    bool decreaseSubstepSize();
 
    void finishElasticSubstep();
 
    void finishSubstep( const TangentSizedMatrix& dXdY );
 
    Matrix6d consistentStiffness();
 
  private:
    const double initialStepSize, minimumStepSize, scaleUpFactor, scaleDownFactor;
    const int    nPassesToIncrease;
 
    double currentProgress;
    double currentSubstepSize;
    int    passedSubsteps;
 
    const Matrix6d& Cel;
 
    TangentSizedMatrix consistentTangent;
  };
} // namespace Marmot::NumericalAlgorithms
 
namespace Marmot::NumericalAlgorithms {
  template < int n >
  PerezFougetSubstepper< n >::PerezFougetSubstepper( double          initialStepSize,
                                                     double          minimumStepSize,
                                                     double          scaleUpFactor,
                                                     double          scaleDownFactor,
                                                     int             nPassesToIncrease,
                                                     const Matrix6d& Cel )
    :
 
      initialStepSize( initialStepSize ),
      minimumStepSize( minimumStepSize ),
      scaleUpFactor( scaleUpFactor ),
      scaleDownFactor( scaleDownFactor ),
      nPassesToIncrease( nPassesToIncrease ),
      currentProgress( 0.0 ),
      currentSubstepSize( initialStepSize ),
      passedSubsteps( 0 ),
      Cel( Cel )
  {
    consistentTangent = TangentSizedMatrix::Zero();
  }
 
  template < int n >
  bool PerezFougetSubstepper< n >::isFinished()
  {
    // this is due to numerical accuracy ...
    return ( 1.0 - currentProgress ) <= 2e-16;
  }
 
  template < int n >
  double PerezFougetSubstepper< n >::getNextSubstep()
  {
    if ( passedSubsteps >= nPassesToIncrease )
      currentSubstepSize *= scaleUpFactor;
 
    const double remainingProgress = 1.0 - currentProgress;
    if ( remainingProgress < currentSubstepSize )
      currentSubstepSize = remainingProgress;
 
    passedSubsteps++;
    currentProgress += currentSubstepSize;
 
    return currentSubstepSize;
  }
 
  template < int n >
  bool PerezFougetSubstepper< n >::decreaseSubstepSize()
  {
    currentProgress -= currentSubstepSize;
    passedSubsteps = 0;
 
    currentSubstepSize *= scaleDownFactor;
 
    if ( currentSubstepSize < minimumStepSize )
      return MarmotJournal::warningToMSG( "UMAT: Substepper: Minimal stepzsize reached" );
    else
      return MarmotJournal::notificationToMSG( "UMAT: Substepper: Decreasing stepsize" );
  }
 
  template < int n >
  void PerezFougetSubstepper< n >::finishElasticSubstep()
  {
    consistentTangent += currentSubstepSize * TangentSizedMatrix::Identity();
  }
 
  template < int n >
  void PerezFougetSubstepper< n >::finishSubstep( const TangentSizedMatrix& dXdY )
  {
    finishElasticSubstep();
    consistentTangent.applyOnTheLeft( dXdY );
 
    for ( int i = 0; i < consistentTangent.rows(); i++ )
      for ( int j = 0; j < consistentTangent.cols(); j++ )
        if ( std::abs( consistentTangent( i, j ) ) < 1e-12 )
          consistentTangent( i, j ) = 0.0;
  }
 
  template < int n >
  Matrix6d PerezFougetSubstepper< n >::consistentStiffness()
  {
    return consistentTangent.topLeftCorner( 6, 6 ) * Cel;
  }
} // namespace Marmot::NumericalAlgorithms