StrainGradDispDerivatives.C

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//* This file is part of the MOOSE framework
//* https://www.mooseframework.org
//*
//* All rights reserved, see COPYRIGHT for full restrictions
//* https://github.com/idaholab/moose/blob/master/COPYRIGHT
//*
//* Licensed under LGPL 2.1, please see LICENSE for details
//* https://www.gnu.org/licenses/lgpl-2.1.html
 
#include "StrainGradDispDerivatives.h"
#include "RankTwoTensor.h"
 
registerMooseObject("PhaseFieldApp", StrainGradDispDerivatives);
 
template <>
InputParameters
validParams<StrainGradDispDerivatives>()
{
  InputParameters params = validParams<Material>();
  params.addClassDescription(
      "Provide the constant derivatives of strain w.r.t. the displacement gradient components.");
  params.addCoupledVar("displacement_gradients",
                       "List of displacement gradient component variables");
  return params;
}
 
StrainGradDispDerivatives::StrainGradDispDerivatives(const InputParameters & parameters)
  : DerivativeMaterialInterface<Material>(parameters),
    _nvar(coupledComponents("displacement_gradients")),
    _dstrain(_nvar)
{
  switch (_nvar)
  {
    case 1:
      _gdim = 1;
      break;
 
    case 4:
      _gdim = 2;
      break;
 
    case 9:
      _gdim = 3;
      break;
 
    default:
      mooseError("Supply 1, 4, or 9 displacement_gradient component variables");
  }
 
  if (_gdim > LIBMESH_DIM)
    mooseError("Too many gradient component variables for the current LIBMESH_DIM");
 
  for (unsigned int i = 0; i < _nvar; ++i)
    _dstrain[i] = &declarePropertyDerivative<RankTwoTensor>(
        "elastic_strain", getVar("displacement_gradients", i)->name());
}
 
void
StrainGradDispDerivatives::computeQpProperties()
{
  unsigned int i = 0;
  for (unsigned int j = 0; j < _gdim; ++j)
    for (unsigned int k = 0; k < _gdim; ++k)
    {
      (*_dstrain[i])[_qp].zero();
      (*_dstrain[i])[_qp](j, k) += 0.5;
      (*_dstrain[i])[_qp](k, j) += 0.5;
      ++i;
    }
}