Computes energy and modifies the stress for phase field fracture. More...

#include <ComputeCrackedStress.h>

Inheritance diagram for ComputeCrackedStress:

Public Member Functions
	ComputeCrackedStress (const InputParameters &parameters)

Static Public Member Functions
static InputParameters	validParams ()

Protected Member Functions
virtual void	computeQpProperties ()

virtual void	initQpStatefulProperties ()

Protected Attributes
const std::string	_base_name
	Base name of the stress after being modified to include cracks. More...

const std::string	_uncracked_base_name
	Base name of the uncracked stress and strain. More...

bool	_finite_strain_model
	Indicator if finite strain model is used, to determine if mechanical_strain or elastic_strain should be used. More...

bool	_use_current_hist
	Use current value of history variable. More...

const MaterialProperty< RankTwoTensor > &	_strain
	Mechanical_strain if finite_strain_model = false, otherwise elastic_strain. More...

const MaterialProperty< RankTwoTensor > &	_uncracked_stress
	Uncracked stress calculated by another material. More...

const MaterialProperty< RankFourTensor > &	_uncracked_Jacobian_mult
	Uncracked Jacobian_mult calculated by another material. More...

const VariableValue &	_c
	Variable defining the phase field damage parameter. More...

const MaterialProperty< Real > &	_gc_prop
	Critical energy release rate for fracture. More...

const MaterialProperty< Real > &	_l
	Characteristic length, controls damage zone thickness. More...

const MaterialProperty< Real > &	_visco

Real	_kdamage
	Small number to avoid non-positive definiteness at or near complete damage. More...

MaterialProperty< RankTwoTensor > &	_stress
	Stress being computed by this kernel. More...

MaterialProperty< Real > &	_F

MaterialProperty< Real > &	_dFdc

MaterialProperty< Real > &	_d2Fdc2

MaterialProperty< RankTwoTensor > &	_d2Fdcdstrain

MaterialProperty< RankTwoTensor > &	_dstress_dc

MaterialProperty< Real > &	_hist
	history variable storing the maximum positive deformation energy More...

const MaterialProperty< Real > &	_hist_old

MaterialProperty< RankFourTensor > &	_Jacobian_mult
	derivative of stress w.r.t. strain (_dstress_dstrain) More...

MaterialProperty< Real > &	_kappa
	Property where the value for kappa will be defined. More...

MaterialProperty< Real > &	_L
	Property where the value for L will be defined. More...

Detailed Description

Computes energy and modifies the stress for phase field fracture.

Can be used with any constitutive model or elastic symmetry.

Definition at line 27 of file ComputeCrackedStress.h.

Constructor & Destructor Documentation

◆ ComputeCrackedStress()

ComputeCrackedStress::ComputeCrackedStress ( const InputParameters & parameters )

Definition at line 40 of file ComputeCrackedStress.C.

   : DerivativeMaterialInterface<Material>(parameters),
     _base_name(isParamValid("base_name") ? getParam<std::string>("base_name") + "_" : ""),
     _uncracked_base_name(getParam<std::string>("uncracked_base_name") + "_"),
     _finite_strain_model(getParam<bool>("finite_strain_model")),
     _use_current_hist(getParam<bool>("use_current_history_variable")),
     _strain(
         _finite_strain_model
             ? getMaterialPropertyByName<RankTwoTensor>(_uncracked_base_name + "elastic_strain")
             : getMaterialPropertyByName<RankTwoTensor>(_uncracked_base_name + "mechanical_strain")),
     _uncracked_stress(getMaterialPropertyByName<RankTwoTensor>(_uncracked_base_name + "stress")),
     _uncracked_Jacobian_mult(
         getMaterialPropertyByName<RankFourTensor>(_uncracked_base_name + "Jacobian_mult")),
     _c(coupledValue("c")),
     _gc_prop(getMaterialProperty<Real>("gc_prop")),
     _l(getMaterialProperty<Real>("l")),
     _visco(getMaterialProperty<Real>("visco")),
     _kdamage(getParam<Real>("kdamage")),
     _stress(declareProperty<RankTwoTensor>(_base_name + "stress")),
     _F(declareProperty<Real>(getParam<MaterialPropertyName>("F_name"))),
     _dFdc(declarePropertyDerivative<Real>(getParam<MaterialPropertyName>("F_name"),
                                           getVar("c", 0)->name())),
     _d2Fdc2(declarePropertyDerivative<Real>(
         getParam<MaterialPropertyName>("F_name"), getVar("c", 0)->name(), getVar("c", 0)->name())),
     _d2Fdcdstrain(declareProperty<RankTwoTensor>("d2Fdcdstrain")),
     _dstress_dc(declarePropertyDerivative<RankTwoTensor>("stress", getVar("c", 0)->name())),
     _hist(declareProperty<Real>("hist")),
     _hist_old(getMaterialPropertyOld<Real>("hist")),
     _Jacobian_mult(declareProperty<RankFourTensor>(_base_name + "Jacobian_mult")),
     _kappa(declareProperty<Real>(getParam<MaterialPropertyName>("kappa_name"))),
     _L(declareProperty<Real>(getParam<MaterialPropertyName>("mobility_name")))
 {
 }

Member Function Documentation

◆ computeQpProperties()

void ComputeCrackedStress::computeQpProperties ( )

protectedvirtual

Definition at line 82 of file ComputeCrackedStress.C.

 {
   const Real c = _c[_qp];
  
   // Zero out values when c > 1
   Real cfactor = 1.0;
   if (c > 1.0)
     cfactor = 0.0;
  
   // Create the positive and negative projection tensors
   RankFourTensor I4sym(RankFourTensor::initIdentitySymmetricFour);
   std::vector<Real> eigval;
   RankTwoTensor eigvec;
   RankFourTensor Ppos = _uncracked_stress[_qp].positiveProjectionEigenDecomposition(eigval, eigvec);
   RankFourTensor Pneg = I4sym - Ppos;
  
   // Project the positive and negative stresses
   RankTwoTensor stress0pos = Ppos * _uncracked_stress[_qp];
   RankTwoTensor stress0neg = Pneg * _uncracked_stress[_qp];
  
   // Compute the positive and negative elastic energies
   Real G0_pos = (stress0pos).doubleContraction(_strain[_qp]) / 2.0;
   Real G0_neg = (stress0neg).doubleContraction(_strain[_qp]) / 2.0;
  
   // Update the history variable
   if (G0_pos > _hist_old[_qp])
     _hist[_qp] = G0_pos;
   else
     _hist[_qp] = _hist_old[_qp];
  
   Real hist_variable = _hist_old[_qp];
   if (_use_current_hist)
     hist_variable = _hist[_qp];
  
   // Compute degredation function and derivatives
   Real h = cfactor * (1.0 - c) * (1.0 - c) * (1.0 - _kdamage) + _kdamage;
   Real dhdc = -2.0 * cfactor * (1.0 - c) * (1.0 - _kdamage);
   Real d2hdc2 = 2.0 * cfactor * (1.0 - _kdamage);
  
   // Compute stress and its derivatives
   _stress[_qp] = (Ppos * h + Pneg) * _uncracked_stress[_qp];
   _dstress_dc[_qp] = stress0pos * dhdc;
   _Jacobian_mult[_qp] = (Ppos * h + Pneg) * _uncracked_Jacobian_mult[_qp];
  
   // Compute energy and its derivatives
   _F[_qp] = hist_variable * h - G0_neg + _gc_prop[_qp] * c * c / (2 * _l[_qp]);
   _dFdc[_qp] = hist_variable * dhdc + _gc_prop[_qp] * c / _l[_qp];
   _d2Fdc2[_qp] = hist_variable * d2hdc2 + _gc_prop[_qp] / _l[_qp];
  
   // 2nd derivative wrt c and strain = 0.0 if we used the previous step's history varible
   if (_use_current_hist)
     _d2Fdcdstrain[_qp] = stress0pos * dhdc;
  
   // Assign L and kappa
   _kappa[_qp] = _gc_prop[_qp] * _l[_qp];
   _L[_qp] = 1.0 / (_gc_prop[_qp] * _visco[_qp]);
 }

◆ initQpStatefulProperties()

void ComputeCrackedStress::initQpStatefulProperties ( )

protectedvirtual

Definition at line 75 of file ComputeCrackedStress.C.

 {
   _stress[_qp].zero();
   _hist[_qp] = 0.0;
 }

◆ validParams()

InputParameters ComputeCrackedStress::validParams ( )

static

Definition at line 17 of file ComputeCrackedStress.C.

 {
   InputParameters params = Material::validParams();
   params.addClassDescription("Computes energy and modifies the stress for phase field fracture");
   params.addRequiredCoupledVar("c", "Order parameter for damage");
   params.addParam<Real>("kdamage", 1e-9, "Stiffness of damaged matrix");
   params.addParam<bool>("finite_strain_model", false, "The model is using finite strain");
   params.addParam<bool>(
       "use_current_history_variable", false, "Use the current value of the history variable.");
   params.addParam<MaterialPropertyName>(
       "F_name", "E_el", "Name of material property storing the elastic energy");
   params.addParam<MaterialPropertyName>(
       "kappa_name",
       "kappa_op",
       "Name of material property being created to store the interfacial parameter kappa");
   params.addParam<MaterialPropertyName>(
       "mobility_name", "L", "Name of material property being created to store the mobility L");
   params.addParam<std::string>("base_name", "The base name used to save the cracked stress");
   params.addRequiredParam<std::string>("uncracked_base_name",
                                        "The base name used to calculate the original stress");
   return params;
 }

Member Data Documentation

◆ _base_name

const std::string ComputeCrackedStress::_base_name

protected

Base name of the stress after being modified to include cracks.

Definition at line 38 of file ComputeCrackedStress.h.

◆ _c

const VariableValue& ComputeCrackedStress::_c

protected

Variable defining the phase field damage parameter.

Definition at line 59 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _d2Fdc2

MaterialProperty<Real>& ComputeCrackedStress::_d2Fdc2

protected

Definition at line 78 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _d2Fdcdstrain

MaterialProperty<RankTwoTensor>& ComputeCrackedStress::_d2Fdcdstrain

protected

Definition at line 79 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _dFdc

MaterialProperty<Real>& ComputeCrackedStress::_dFdc

protected

Definition at line 77 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _dstress_dc

MaterialProperty<RankTwoTensor>& ComputeCrackedStress::_dstress_dc

protected

Definition at line 80 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _F

MaterialProperty<Real>& ComputeCrackedStress::_F

protected

Definition at line 76 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _finite_strain_model

bool ComputeCrackedStress::_finite_strain_model

protected

Indicator if finite strain model is used, to determine if mechanical_strain or elastic_strain should be used.

Definition at line 44 of file ComputeCrackedStress.h.

◆ _gc_prop

const MaterialProperty<Real>& ComputeCrackedStress::_gc_prop

protected

Critical energy release rate for fracture.

Definition at line 62 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _hist

MaterialProperty<Real>& ComputeCrackedStress::_hist

protected

history variable storing the maximum positive deformation energy

Definition at line 83 of file ComputeCrackedStress.h.

Referenced by computeQpProperties(), and initQpStatefulProperties().

◆ _hist_old

const MaterialProperty<Real>& ComputeCrackedStress::_hist_old

protected

Definition at line 84 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _Jacobian_mult

MaterialProperty<RankFourTensor>& ComputeCrackedStress::_Jacobian_mult

protected

derivative of stress w.r.t. strain (_dstress_dstrain)

Definition at line 87 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _kappa

MaterialProperty<Real>& ComputeCrackedStress::_kappa

protected

Property where the value for kappa will be defined.

Definition at line 90 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _kdamage

Real ComputeCrackedStress::_kdamage

protected

Small number to avoid non-positive definiteness at or near complete damage.

Definition at line 71 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _l

const MaterialProperty<Real>& ComputeCrackedStress::_l

protected

Characteristic length, controls damage zone thickness.

Definition at line 65 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _L

MaterialProperty<Real>& ComputeCrackedStress::_L

protected

Property where the value for L will be defined.

Definition at line 93 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _strain

const MaterialProperty<RankTwoTensor>& ComputeCrackedStress::_strain

protected

Mechanical_strain if finite_strain_model = false, otherwise elastic_strain.

Definition at line 50 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _stress

MaterialProperty<RankTwoTensor>& ComputeCrackedStress::_stress

protected

Stress being computed by this kernel.

Definition at line 74 of file ComputeCrackedStress.h.

Referenced by computeQpProperties(), and initQpStatefulProperties().

◆ _uncracked_base_name

const std::string ComputeCrackedStress::_uncracked_base_name

protected

Base name of the uncracked stress and strain.

Definition at line 41 of file ComputeCrackedStress.h.

◆ _uncracked_Jacobian_mult

const MaterialProperty<RankFourTensor>& ComputeCrackedStress::_uncracked_Jacobian_mult

protected

Uncracked Jacobian_mult calculated by another material.

Definition at line 56 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _uncracked_stress

const MaterialProperty<RankTwoTensor>& ComputeCrackedStress::_uncracked_stress

protected

Uncracked stress calculated by another material.

Definition at line 53 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _use_current_hist

bool ComputeCrackedStress::_use_current_hist

protected

Use current value of history variable.

Definition at line 47 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

◆ _visco

const MaterialProperty<Real>& ComputeCrackedStress::_visco

protected

Definition at line 68 of file ComputeCrackedStress.h.

Referenced by computeQpProperties().

The documentation for this class was generated from the following files:

tensor_mechanics/include/materials/ComputeCrackedStress.h
tensor_mechanics/src/materials/ComputeCrackedStress.C

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ComputeCrackedStress()

Member Function Documentation

◆ computeQpProperties()

◆ initQpStatefulProperties()

◆ validParams()

Member Data Documentation

◆ _base_name

◆ _c

◆ _d2Fdc2

◆ _d2Fdcdstrain

◆ _dFdc

◆ _dstress_dc

◆ _F

◆ _finite_strain_model

◆ _gc_prop

◆ _hist

◆ _hist_old

◆ _Jacobian_mult

◆ _kappa

◆ _kdamage

◆ _l

◆ _L

◆ _strain

◆ _stress

◆ _uncracked_base_name

◆ _uncracked_Jacobian_mult

◆ _uncracked_stress

◆ _use_current_hist

◆ _visco