Material class for 2D correspondence material model for finite strain: plane strain, generalized plane strain, weak plane stress. More...

#include <ComputePlaneFiniteStrainNOSPD.h>

Inheritance diagram for ComputePlaneFiniteStrainNOSPD:

[legend]

Public Types
typedef DerivativeMaterialPropertyNameInterface::SymbolName	SymbolName

Public Member Functions
	ComputePlaneFiniteStrainNOSPD (const InputParameters &parameters)

virtual void	initQpStatefulProperties () override

const GenericMaterialProperty< U, is_ad > &	getDefaultMaterialProperty (const std::string &name)

const GenericMaterialProperty< U, is_ad > &	getDefaultMaterialPropertyByName (const std::string &name)

void	validateDerivativeMaterialPropertyBase (const std::string &base)

const MaterialPropertyName	derivativePropertyName (const MaterialPropertyName &base, const std::vector< SymbolName > &c) const

const MaterialPropertyName	derivativePropertyNameFirst (const MaterialPropertyName &base, const SymbolName &c1) const

const MaterialPropertyName	derivativePropertyNameSecond (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2) const

const MaterialPropertyName	derivativePropertyNameThird (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2, const SymbolName &c3) const

GenericMaterialProperty< U, is_ad > &	declarePropertyDerivative (const std::string &base, const std::vector< VariableName > &c)

GenericMaterialProperty< U, is_ad > &	declarePropertyDerivative (const std::string &base, const std::vector< SymbolName > &c)

GenericMaterialProperty< U, is_ad > &	declarePropertyDerivative (const std::string &base, const SymbolName &c1, const SymbolName &c2="", const SymbolName &c3="")

GenericMaterialProperty< U, is_ad > &	declarePropertyDerivative (const std::string &base, const std::vector< VariableName > &c)

GenericMaterialProperty< U, is_ad > &	declarePropertyDerivative (const std::string &base, const std::vector< SymbolName > &c)

GenericMaterialProperty< U, is_ad > &	declarePropertyDerivative (const std::string &base, const SymbolName &c1, const SymbolName &c2="", const SymbolName &c3="")

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const std::vector< VariableName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const std::vector< SymbolName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const SymbolName &c1, const SymbolName &c2="", const SymbolName &c3="")

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const SymbolName &c1, unsigned int v2, unsigned int v3=libMesh::invalid_uint)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, unsigned int v1, unsigned int v2=libMesh::invalid_uint, unsigned int v3=libMesh::invalid_uint)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const std::vector< VariableName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const std::vector< SymbolName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const SymbolName &c1, const SymbolName &c2="", const SymbolName &c3="")

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, const SymbolName &c1, unsigned int v2, unsigned int v3=libMesh::invalid_uint)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivative (const std::string &base, unsigned int v1, unsigned int v2=libMesh::invalid_uint, unsigned int v3=libMesh::invalid_uint)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivativeByName (const MaterialPropertyName &base, const std::vector< VariableName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivativeByName (const MaterialPropertyName &base, const std::vector< SymbolName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivativeByName (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2="", const SymbolName &c3="")

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivativeByName (const MaterialPropertyName &base, const std::vector< VariableName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivativeByName (const MaterialPropertyName &base, const std::vector< SymbolName > &c)

const GenericMaterialProperty< U, is_ad > &	getMaterialPropertyDerivativeByName (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2="", const SymbolName &c3="")

void	validateCoupling (const MaterialPropertyName &base, const std::vector< VariableName > &c, bool validate_aux=true)

void	validateCoupling (const MaterialPropertyName &base, const VariableName &c1="", const VariableName &c2="", const VariableName &c3="")

void	validateCoupling (const MaterialPropertyName &base, const std::vector< VariableName > &c, bool validate_aux=true)

void	validateCoupling (const MaterialPropertyName &base, const VariableName &c1="", const VariableName &c2="", const VariableName &c3="")

void	validateNonlinearCoupling (const MaterialPropertyName &base, const VariableName &c1="", const VariableName &c2="", const VariableName &c3="")

void	validateNonlinearCoupling (const MaterialPropertyName &base, const VariableName &c1="", const VariableName &c2="", const VariableName &c3="")

const MaterialPropertyName	propertyName (const MaterialPropertyName &base, const std::vector< SymbolName > &c) const

const MaterialPropertyName	propertyName (const MaterialPropertyName &base, const std::vector< SymbolName > &c) const

const MaterialPropertyName	propertyNameFirst (const MaterialPropertyName &base, const SymbolName &c1) const

const MaterialPropertyName	propertyNameFirst (const MaterialPropertyName &base, const SymbolName &c1) const

const MaterialPropertyName	propertyNameSecond (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2) const

const MaterialPropertyName	propertyNameSecond (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2) const

const MaterialPropertyName	propertyNameThird (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2, const SymbolName &c3) const

const MaterialPropertyName	propertyNameThird (const MaterialPropertyName &base, const SymbolName &c1, const SymbolName &c2, const SymbolName &c3) const

Static Public Member Functions
static InputParameters	validParams ()

static MooseEnum	decompositionType ()

Protected Member Functions
virtual void	computeQpFhat () override

virtual void	computeQpStrain () override
	Function to compute strain tensors.

void	computeQpStrainRotationIncrements (RankTwoTensor &e, RankTwoTensor &r)
	Function to compute strain and rotational increments.

void	subtractEigenstrainIncrementFromStrain (RankTwoTensor &strain)
	Function to compute the mechanical strain tensor by subtracting thermal strain from the total strain.

virtual void	computeProperties () override

virtual void	computeBondStretch () override

virtual void	computeQpDeformationGradient ()
	Function to compute deformation gradient for peridynamic correspondence model.

virtual void	computeConventionalQpDeformationGradient ()
	Function to compute conventional nonlocal deformation gradient.

virtual void	computeBondHorizonQpDeformationGradient ()
	Function to compute bond-associated horizon based deformation gradient.


virtual Real	computeQpOutOfPlaneDeformationGradient ()
	Functions to compute the out-of-plane component of deformation gradient for generalized plane strain and weak plane stress.

virtual Real	computeQpOutOfPlaneDeformationGradientOld ()

Protected Attributes
std::vector< RankTwoTensor >	_Fhat
	'Incremental' deformation gradient

const MooseEnum	_stabilization
	Option of stabilization scheme for correspondence material model: FORCE, BOND_HORIZON_I or BOND_HORIZON_II.

const bool	_plane_strain
	Plane strain problem or not, this is only used for mechanical stretch calculation.


MaterialProperty< RankTwoTensor > &	_strain_rate
	Material properties to store.

MaterialProperty< RankTwoTensor > &	_strain_increment

MaterialProperty< RankTwoTensor > &	_rotation_increment


const MaterialProperty< RankTwoTensor > &	_deformation_gradient_old
	Material properties to fetch.

const MaterialProperty< RankTwoTensor > &	_mechanical_strain_old

const MaterialProperty< RankTwoTensor > &	_total_strain_old

std::vector< const MaterialProperty< RankTwoTensor > * >	_eigenstrains_old


const MaterialProperty< RankFourTensor > &	_Cijkl
	Material properties to fetch.

std::vector< MaterialPropertyName >	_eigenstrain_names

std::vector< const MaterialProperty< RankTwoTensor > * >	_eigenstrains


MaterialProperty< RankTwoTensor > &	_shape2
	Material properties to store.

MaterialProperty< RankTwoTensor > &	_deformation_gradient

MaterialProperty< RankTwoTensor > &	_ddgraddu

MaterialProperty< RankTwoTensor > &	_ddgraddv

MaterialProperty< RankTwoTensor > &	_ddgraddw

MaterialProperty< RankTwoTensor > &	_total_strain

MaterialProperty< RankTwoTensor > &	_mechanical_strain

MaterialProperty< Real > &	_multi

MaterialProperty< Real > &	_sf_coeff
	fictitious force coefficient for force stabilized model

Private Member Functions
bool	haveMaterialProperty (const std::string &prop_name)

std::vector< VariableName >	buildVariableVector (const VariableName &c1, const VariableName &c2, const VariableName &c3)

void	validateCouplingHelper (const MaterialPropertyName &base, const std::vector< VariableName > &c, const System &system, std::vector< VariableName > &missing)

bool	isNotObjectVariable (const VariableName &name)

Private Attributes
FEProblemBase &	_dmi_fe_problem


const bool	_scalar_out_of_plane_strain_coupled
	Scalar out-of-plane strain for generalized plane strain.

const VariableValue &	_scalar_out_of_plane_strain

const VariableValue &	_scalar_out_of_plane_strain_old


const bool	_out_of_plane_strain_coupled
	Out-of-plane strain for weak plane stress.

const VariableValue &	_out_of_plane_strain

const VariableValue &	_out_of_plane_strain_old

const DecompMethod	_decomposition_method

enum class	DecompMethod { TaylorExpansion , EigenSolution }
	Method to decompose into rotation increment and strain increment. More...

Detailed Description

Material class for 2D correspondence material model for finite strain: plane strain, generalized plane strain, weak plane stress.

Definition at line 18 of file ComputePlaneFiniteStrainNOSPD.h.

Member Enumeration Documentation

◆ DecompMethod

enum class ComputeFiniteStrainNOSPD::DecompMethod

strongprivateinherited

Method to decompose into rotation increment and strain increment.

Enumerator
TaylorExpansion
EigenSolution

Definition at line 60 of file ComputeFiniteStrainNOSPD.h.

  {
    TaylorExpansion,
    EigenSolution
  };

Constructor & Destructor Documentation

◆ ComputePlaneFiniteStrainNOSPD()

ComputePlaneFiniteStrainNOSPD::ComputePlaneFiniteStrainNOSPD ( const InputParameters & parameters )

Definition at line 31 of file ComputePlaneFiniteStrainNOSPD.C.

  : ComputeFiniteStrainNOSPD(parameters),
    _scalar_out_of_plane_strain_coupled(isCoupledScalar("scalar_out_of_plane_strain")),
    _scalar_out_of_plane_strain(_scalar_out_of_plane_strain_coupled
                                    ? coupledScalarValue("scalar_out_of_plane_strain")
                                    : _zero),
    _scalar_out_of_plane_strain_old(_scalar_out_of_plane_strain_coupled
                                        ? coupledScalarValueOld("scalar_out_of_plane_strain")
                                        : _zero),
    _out_of_plane_strain_coupled(isCoupled("out_of_plane_strain")),
    _out_of_plane_strain(_out_of_plane_strain_coupled ? coupledValue("out_of_plane_strain")
                                                      : _zero),
    _out_of_plane_strain_old(_out_of_plane_strain_coupled ? coupledValueOld("out_of_plane_strain")
                                                          : _zero)
{
}

Member Function Documentation

◆ computeBondHorizonQpDeformationGradient()

void ComputeStrainBaseNOSPD::computeBondHorizonQpDeformationGradient ( )

protectedvirtualinherited

Function to compute bond-associated horizon based deformation gradient.

Definition at line 163 of file ComputeStrainBaseNOSPD.C.

{
  std::vector<dof_id_type> neighbors = _pdmesh.getNeighbors(_current_elem->node_id(_qp));
  std::vector<dof_id_type> bonds = _pdmesh.getBonds(_current_elem->node_id(_qp));
 
  dof_id_type nb_index =
      std::find(neighbors.begin(), neighbors.end(), _current_elem->node_id(1 - _qp)) -
      neighbors.begin();
  std::vector<dof_id_type> dg_neighbors =
      _pdmesh.getBondDeformationGradientNeighbors(_current_elem->node_id(_qp), nb_index);
  Real dg_sub_vol = _pdmesh.getHorizonSubsetVolume(_current_elem->node_id(_qp), nb_index);
  Real dg_sub_vol_sum = _pdmesh.getHorizonSubsetVolumeSum(_current_elem->node_id(_qp));
 
  // calculate the shape tensor and prepare the deformation gradient tensor
  Real vol_nb, weight_nb;
  RealGradient origin_vec_nb, current_vec_nb;
 
  for (unsigned int nb = 0; nb < dg_neighbors.size(); ++nb)
    if (_bond_status_var->getElementalValue(_pdmesh.elemPtr(bonds[dg_neighbors[nb]])) > 0.5)
    {
      vol_nb = _pdmesh.getNodeVolume(neighbors[dg_neighbors[nb]]);
      origin_vec_nb = _pdmesh.getNodeCoord(neighbors[dg_neighbors[nb]]) -
                      _pdmesh.getNodeCoord(_current_elem->node_id(_qp));
 
      for (unsigned int k = 0; k < _dim; ++k)
        current_vec_nb(k) =
            origin_vec_nb(k) +
            _disp_var[k]->getNodalValue(*_pdmesh.nodePtr(neighbors[dg_neighbors[nb]])) -
            _disp_var[k]->getNodalValue(*_current_elem->node_ptr(_qp));
 
      weight_nb = _horizon_radius[_qp] / origin_vec_nb.norm();
      for (unsigned int k = 0; k < _dim; ++k)
      {
        for (unsigned int l = 0; l < _dim; ++l)
        {
          _shape2[_qp](k, l) += weight_nb * origin_vec_nb(k) * origin_vec_nb(l) * vol_nb;
          _deformation_gradient[_qp](k, l) +=
              weight_nb * current_vec_nb(k) * origin_vec_nb(l) * vol_nb;
        }
        // calculate derivatives of deformation_gradient w.r.t displacements of node i
        _ddgraddu[_qp](0, k) += -weight_nb * origin_vec_nb(k) * vol_nb;
        _ddgraddv[_qp](1, k) += -weight_nb * origin_vec_nb(k) * vol_nb;
        if (_dim == 3)
          _ddgraddw[_qp](2, k) += -weight_nb * origin_vec_nb(k) * vol_nb;
      }
    }
  // finalize the deformation gradient and its derivatives
  if (_shape2[_qp].det() == 0.)
    computeConventionalQpDeformationGradient(); // this will affect the corresponding jacobian
                                                // calculation
  else
  {
    _deformation_gradient[_qp] *= _shape2[_qp].inverse();
    _ddgraddu[_qp] *= _shape2[_qp].inverse();
    _ddgraddv[_qp] *= _shape2[_qp].inverse();
    _ddgraddw[_qp] *= _shape2[_qp].inverse();
  }
 
  // force state multiplier
  if (_stabilization == "BOND_HORIZON_I")
    _multi[_qp] = _horizon_radius[_qp] / _origin_vec.norm() * _node_vol[0] * _node_vol[1] *
                  dg_sub_vol / _horizon_vol[_qp];
  else if (_stabilization == "BOND_HORIZON_II")
    _multi[_qp] = _node_vol[_qp] * dg_sub_vol / dg_sub_vol_sum;
}

Referenced by ComputeStrainBaseNOSPD::computeQpDeformationGradient().

◆ computeBondStretch()

void ComputeStrainBaseNOSPD::computeBondStretch ( )

overrideprotectedvirtualinherited

Definition at line 241 of file ComputeStrainBaseNOSPD.C.

{
  _total_stretch[0] = _current_len / _origin_vec.norm() - 1.0;
  _total_stretch[1] = _total_stretch[0];
  _mechanical_stretch[0] = _total_stretch[0];
 
  Real factor = 1.0;
  if (_plane_strain)
    factor = 1.0 + ElasticityTensorTools::getIsotropicPoissonsRatio(_Cijkl[0]);
 
  for (auto es : _eigenstrains)
    _mechanical_stretch[0] -= 0.5 * factor * ((*es)[0](2, 2) + (*es)[1](2, 2));
 
  _mechanical_stretch[1] = _mechanical_stretch[0];
}

Referenced by ComputeStrainBaseNOSPD::computeProperties().

◆ computeConventionalQpDeformationGradient()

void ComputeStrainBaseNOSPD::computeConventionalQpDeformationGradient ( )

protectedvirtualinherited

Function to compute conventional nonlocal deformation gradient.

Definition at line 113 of file ComputeStrainBaseNOSPD.C.

{
  std::vector<dof_id_type> neighbors = _pdmesh.getNeighbors(_current_elem->node_id(_qp));
  std::vector<dof_id_type> bonds = _pdmesh.getBonds(_current_elem->node_id(_qp));
 
  // calculate the shape tensor and prepare the deformation gradient tensor
  Real vol_nb, weight_nb;
  RealGradient origin_vec_nb, current_vec_nb;
 
  for (unsigned int nb = 0; nb < neighbors.size(); ++nb)
    if (_bond_status_var->getElementalValue(_pdmesh.elemPtr(bonds[nb])) > 0.5)
    {
      vol_nb = _pdmesh.getNodeVolume(neighbors[nb]);
      origin_vec_nb =
          _pdmesh.getNodeCoord(neighbors[nb]) - _pdmesh.getNodeCoord(_current_elem->node_id(_qp));
 
      for (unsigned int k = 0; k < _dim; ++k)
        current_vec_nb(k) = origin_vec_nb(k) +
                            _disp_var[k]->getNodalValue(*_pdmesh.nodePtr(neighbors[nb])) -
                            _disp_var[k]->getNodalValue(*_current_elem->node_ptr(_qp));
 
      weight_nb = _horizon_radius[_qp] / origin_vec_nb.norm();
      for (unsigned int k = 0; k < _dim; ++k)
      {
        for (unsigned int l = 0; l < _dim; ++l)
        {
          _shape2[_qp](k, l) += weight_nb * origin_vec_nb(k) * origin_vec_nb(l) * vol_nb;
          _deformation_gradient[_qp](k, l) +=
              weight_nb * current_vec_nb(k) * origin_vec_nb(l) * vol_nb;
        }
        // calculate derivatives of deformation_gradient w.r.t displacements of node nb
        _ddgraddu[_qp](0, k) += -weight_nb * origin_vec_nb(k) * vol_nb;
        _ddgraddv[_qp](1, k) += -weight_nb * origin_vec_nb(k) * vol_nb;
        if (_dim == 3)
          _ddgraddw[_qp](2, k) += -weight_nb * origin_vec_nb(k) * vol_nb;
      }
    }
 
  // finalize the deformation gradient tensor
  if (_shape2[_qp].det() == 0.)
    mooseError("Singular shape tensor is detected in ComputeStrainBaseNOSPD! Use "
               "SingularShapeTensorEliminatorUserObjectPD to avoid singular shape tensor!");
 
  _deformation_gradient[_qp] *= _shape2[_qp].inverse();
  _ddgraddu[_qp] *= _shape2[_qp].inverse();
  _ddgraddv[_qp] *= _shape2[_qp].inverse();
  _ddgraddw[_qp] *= _shape2[_qp].inverse();
}

Referenced by ComputeStrainBaseNOSPD::computeBondHorizonQpDeformationGradient(), and ComputeStrainBaseNOSPD::computeQpDeformationGradient().

◆ computeProperties()

void ComputeStrainBaseNOSPD::computeProperties ( )

overrideprotectedvirtualinherited

Definition at line 230 of file ComputeStrainBaseNOSPD.C.

{
  setupMeshRelatedData();     // function from base class
  computeBondCurrentLength(); // current length of a bond from base class
  computeBondStretch();       // stretch of a bond
 
  for (_qp = 0; _qp < _nnodes; ++_qp)
    computeQpStrain();
}

◆ computeQpDeformationGradient()

void ComputeStrainBaseNOSPD::computeQpDeformationGradient ( )

protectedvirtualinherited

Function to compute deformation gradient for peridynamic correspondence model.

Definition at line 75 of file ComputeStrainBaseNOSPD.C.

{
  _shape2[_qp].zero();
  _deformation_gradient[_qp].zero();
  _ddgraddu[_qp].zero();
  _ddgraddv[_qp].zero();
  _ddgraddw[_qp].zero();
  _multi[_qp] = 0.0;
  _sf_coeff[_qp] = 0.0;
 
  if (_dim == 2)
    _shape2[_qp](2, 2) = _deformation_gradient[_qp](2, 2) = 1.0;
 
  if (_bond_status_var->getElementalValue(_current_elem) > 0.5)
  {
    if (_stabilization == "FORCE")
    {
      computeConventionalQpDeformationGradient();
 
      _sf_coeff[_qp] = ElasticityTensorTools::getIsotropicYoungsModulus(_Cijkl[_qp]) *
                       _pdmesh.getNodeAverageSpacing(_current_elem->node_id(_qp)) *
                       _horizon_radius[_qp] / _origin_vec.norm();
      _multi[_qp] = _horizon_radius[_qp] / _origin_vec.norm() * _node_vol[0] * _node_vol[1];
    }
    else if (_stabilization == "BOND_HORIZON_I" || _stabilization == "BOND_HORIZON_II")
      computeBondHorizonQpDeformationGradient();
    else
      paramError("stabilization",
                 "Unknown stabilization scheme for peridynamic correspondence model!");
  }
  else
  {
    _shape2[_qp].setToIdentity();
    _deformation_gradient[_qp].setToIdentity();
  }
}

Referenced by ComputeFiniteStrainNOSPD::computeQpStrain(), and ComputeSmallStrainNOSPD::computeQpStrain().

◆ computeQpFhat()

void ComputePlaneFiniteStrainNOSPD::computeQpFhat ( )

overrideprotectedvirtual

Reimplemented from ComputeFiniteStrainNOSPD.

Definition at line 49 of file ComputePlaneFiniteStrainNOSPD.C.

{
  _deformation_gradient[_qp](2, 2) = computeQpOutOfPlaneDeformationGradient();
 
  RankTwoTensor deformation_gradient_old = _deformation_gradient_old[_qp];
  deformation_gradient_old(2, 2) = computeQpOutOfPlaneDeformationGradientOld();
 
  // Incremental deformation gradient of current step w.r.t previous step:
  // _Fhat = deformation_gradient * inv(deformation_gradient_old)
  _Fhat[_qp] = _deformation_gradient[_qp] * deformation_gradient_old.inverse();
}

◆ computeQpOutOfPlaneDeformationGradient()

Real ComputePlaneFiniteStrainNOSPD::computeQpOutOfPlaneDeformationGradient ( )

protectedvirtual

Functions to compute the out-of-plane component of deformation gradient for generalized plane strain and weak plane stress.

Definition at line 62 of file ComputePlaneFiniteStrainNOSPD.C.

{
  // This is consistent with the approximation of stretch rate tensor
  // D = log(sqrt(Fhat^T * Fhat)) / dt
 
  if (_scalar_out_of_plane_strain_coupled)
    return std::exp(_scalar_out_of_plane_strain[0]);
  else
    return std::exp(_out_of_plane_strain[_qp]);
}

Referenced by computeQpFhat().

◆ computeQpOutOfPlaneDeformationGradientOld()

Real ComputePlaneFiniteStrainNOSPD::computeQpOutOfPlaneDeformationGradientOld ( )

protectedvirtual

Definition at line 74 of file ComputePlaneFiniteStrainNOSPD.C.

{
  if (_scalar_out_of_plane_strain_coupled)
    return std::exp(_scalar_out_of_plane_strain_old[0]);
  else
    return std::exp(_out_of_plane_strain_old[_qp]);
}

Referenced by computeQpFhat().

◆ computeQpStrain()

void ComputeFiniteStrainNOSPD::computeQpStrain ( )

overrideprotectedvirtualinherited

Function to compute strain tensors.

Implements ComputeStrainBaseNOSPD.

Definition at line 54 of file ComputeFiniteStrainNOSPD.C.

{
  computeQpDeformationGradient();
 
  computeQpFhat();
 
  RankTwoTensor total_strain_increment;
 
  // Two ways to calculate these increments: TaylorExpansion(default) or EigenSolution
  computeQpStrainRotationIncrements(total_strain_increment, _rotation_increment[_qp]);
 
  _strain_increment[_qp] = total_strain_increment;
 
  // Remove the eigenstrain increment
  subtractEigenstrainIncrementFromStrain(_strain_increment[_qp]);
 
  if (_dt > 0)
    _strain_rate[_qp] = _strain_increment[_qp] / _dt;
  else
    _strain_rate[_qp].zero();
 
  // Update strain in intermediate configuration
  _mechanical_strain[_qp] = _mechanical_strain_old[_qp] + _strain_increment[_qp];
  _total_strain[_qp] = _total_strain_old[_qp] + total_strain_increment;
 
  // Rotate strain to current configuration
  _mechanical_strain[_qp] =
      _rotation_increment[_qp] * _mechanical_strain[_qp] * _rotation_increment[_qp].transpose();
  _total_strain[_qp] =
      _rotation_increment[_qp] * _total_strain[_qp] * _rotation_increment[_qp].transpose();
 
  // zero out all strain measures for broken bond
  if (_bond_status_var->getElementalValue(_current_elem) < 0.5)
  {
    _strain_rate[_qp].zero();
    _strain_increment[_qp].zero();
    _rotation_increment[_qp].zero();
    _mechanical_strain[_qp].zero();
    _total_strain[_qp].zero();
  }
}

◆ computeQpStrainRotationIncrements()

void ComputeFiniteStrainNOSPD::computeQpStrainRotationIncrements	(	RankTwoTensor &	e,
		RankTwoTensor &	r
	)

protectedinherited

Function to compute strain and rotational increments.

Definition at line 105 of file ComputeFiniteStrainNOSPD.C.

{
  switch (_decomposition_method)
  {
    case DecompMethod::TaylorExpansion:
    {
      // inverse of _Fhat
      RankTwoTensor invFhat(_Fhat[_qp].inverse());
 
      // A = I - _Fhat^-1
      RankTwoTensor A(RankTwoTensor::initIdentity);
      A -= invFhat;
 
      // Cinv - I = A A^T - A - A^T;
      RankTwoTensor Cinv_I = A * A.transpose() - A - A.transpose();
 
      // strain rate D from Taylor expansion, Chat = (-1/2(Chat^-1 - I) + 1/4*(Chat^-1 - I)^2 + ...
      total_strain_increment = -Cinv_I * 0.5 + Cinv_I * Cinv_I * 0.25;
 
      const Real a[3] = {invFhat(1, 2) - invFhat(2, 1),
                         invFhat(2, 0) - invFhat(0, 2),
                         invFhat(0, 1) - invFhat(1, 0)};
 
      Real q = (a[0] * a[0] + a[1] * a[1] + a[2] * a[2]) / 4.0;
      Real trFhatinv_1 = invFhat.trace() - 1.0;
      const Real p = trFhatinv_1 * trFhatinv_1 / 4.0;
 
      // cos theta_a
      const Real C1_squared = p +
                              3.0 * Utility::pow<2>(p) * (1.0 - (p + q)) / Utility::pow<2>(p + q) -
                              2.0 * Utility::pow<3>(p) * (1.0 - (p + q)) / Utility::pow<3>(p + q);
      if (C1_squared <= 0.0)
        mooseException(
            "Cannot take square root of a number less than or equal to zero in the calculation of "
            "C1 for the Rashid approximation for the rotation tensor.");
 
      const Real C1 = std::sqrt(C1_squared);
 
      Real C2;
      if (q > 0.01)
        // (1-cos theta_a)/4q
        C2 = (1.0 - C1) / (4.0 * q);
      else
        // alternate form for small q
        C2 = 0.125 + q * 0.03125 * (Utility::pow<2>(p) - 12.0 * (p - 1.0)) / Utility::pow<2>(p) +
             Utility::pow<2>(q) * (p - 2.0) * (Utility::pow<2>(p) - 10.0 * p + 32.0) /
                 Utility::pow<3>(p) +
             Utility::pow<3>(q) *
                 (1104.0 - 992.0 * p + 376.0 * Utility::pow<2>(p) - 72.0 * Utility::pow<3>(p) +
                  5.0 * Utility::pow<4>(p)) /
                 (512.0 * Utility::pow<4>(p));
 
      const Real C3_test =
          (p * q * (3.0 - q) + Utility::pow<3>(p) + Utility::pow<2>(q)) / Utility::pow<3>(p + q);
 
      if (C3_test <= 0.0)
        mooseException(
            "Cannot take square root of a number less than or equal to zero in the calculation of "
            "C3_test for the Rashid approximation for the rotation tensor.");
 
      const Real C3 = 0.5 * std::sqrt(C3_test); // sin theta_a/(2 sqrt(q))
 
      // Calculate incremental rotation. Note that this value is the transpose of that from Rashid,
      // 93, so we transpose it before storing
      RankTwoTensor R_incr;
      R_incr.addIa(C1);
      for (unsigned int i = 0; i < 3; ++i)
        for (unsigned int j = 0; j < 3; ++j)
          R_incr(i, j) += C2 * a[i] * a[j];
 
      R_incr(0, 1) += C3 * a[2];
      R_incr(0, 2) -= C3 * a[1];
      R_incr(1, 0) -= C3 * a[2];
      R_incr(1, 2) += C3 * a[0];
      R_incr(2, 0) += C3 * a[1];
      R_incr(2, 1) -= C3 * a[0];
 
      rotation_increment = R_incr.transpose();
      break;
    }
    case DecompMethod::EigenSolution:
    {
      FactorizedRankTwoTensor Chat = RankTwoTensor::transposeTimes(_Fhat[_qp]);
      FactorizedRankTwoTensor Uhat = MathUtils::sqrt(Chat);
      rotation_increment = _Fhat[_qp] * Uhat.inverse().get();
      total_strain_increment = MathUtils::log(Uhat).get();
      break;
    }
 
    default:
      mooseError("ComputeFiniteStrainNOSPD Error: Invalid decomposition type! Please specify : "
                 "TaylorExpansion or "
                 "EigenSolution.");
  }
}

Referenced by ComputeFiniteStrainNOSPD::computeQpStrain().

◆ decompositionType()

MooseEnum ComputeFiniteStrainNOSPD::decompositionType ( )

staticinherited

Definition at line 17 of file ComputeFiniteStrainNOSPD.C.

{
  return MooseEnum("TaylorExpansion EigenSolution", "TaylorExpansion");
}

Referenced by ComputeFiniteStrainNOSPD::validParams().

◆ initQpStatefulProperties()

void ComputeStrainBaseNOSPD::initQpStatefulProperties ( )

overridevirtualinherited

Definition at line 62 of file ComputeStrainBaseNOSPD.C.

{
  _mechanical_strain[_qp].zero();
  _total_strain[_qp].zero();
  _deformation_gradient[_qp].setToIdentity();
 
  if (_qrule->n_points() < 2) // Gauss_Lobatto: order = 2n-3 (n is number of qp)
    mooseError(
        "NOSPD models require Gauss_Lobatto rule and a minimum of 2 quadrature points, i.e., "
        "order of FIRST");
}

◆ subtractEigenstrainIncrementFromStrain()

void ComputeFiniteStrainNOSPD::subtractEigenstrainIncrementFromStrain ( RankTwoTensor & strain )

protectedinherited

Function to compute the mechanical strain tensor by subtracting thermal strain from the total strain.

Definition at line 203 of file ComputeFiniteStrainNOSPD.C.

{
  for (unsigned int i = 0; i < _eigenstrains.size(); ++i)
  {
    strain -= (*_eigenstrains[i])[_qp];
    strain += (*_eigenstrains_old[i])[_qp];
  }
}

Referenced by ComputeFiniteStrainNOSPD::computeQpStrain().

◆ validParams()

InputParameters ComputePlaneFiniteStrainNOSPD::validParams ( )

static

Definition at line 15 of file ComputePlaneFiniteStrainNOSPD.C.

{
  InputParameters params = ComputeFiniteStrainNOSPD::validParams();
  params.addClassDescription(
      "Class for computing nodal quantities for residual and jacobian calculation "
      "for peridynamic correspondence models under planar finite strain "
      "assumptions");
 
  params.addCoupledVar("scalar_out_of_plane_strain",
                       "Scalar out-of-plane strain variable for generalized plane strain");
  params.addCoupledVar("out_of_plane_strain",
                       "Nonlinear out-of-plane strain variable for plane stress condition");
 
  return params;
}