Computes the stress of a linear viscoelastic material, using total small strains. More...

#include <ComputeLinearViscoelasticStress.h>

Inheritance diagram for ComputeLinearViscoelasticStress:

Public Member Functions
	ComputeLinearViscoelasticStress (const InputParameters &parameters)

virtual void	initialSetup () override

Static Public Member Functions
static InputParameters	validParams ()

Protected Member Functions
virtual void	initQpStatefulProperties () override

virtual void	computeQpStress () override
	Compute the stress and store it in the _stress material property for the current quadrature point. More...

virtual void	computeQpProperties () override

Protected Attributes
const MaterialProperty< RankTwoTensor > &	_apparent_creep_strain
	Apparent creep strain (extracted from a LinearViscoelasticityBase object) More...

const MaterialProperty< RankFourTensor > &	_apparent_elasticity_tensor
	Apparent elasticity tensor (extracted from a LinearViscoelasticityBase object) More...

const MaterialProperty< RankFourTensor > &	_elasticity_tensor_inv
	Instantaneous compliance tensor (extracted from a LinearViscoelasticityBase object) More...

const std::string	_elasticity_tensor_name
	Name of the elasticity tensor material property. More...

const MaterialProperty< RankFourTensor > &	_elasticity_tensor
	Elasticity tensor material property. More...

const std::string	_base_name
	Base name prepended to all material property names to allow for multi-material systems. More...

const MaterialProperty< RankTwoTensor > &	_mechanical_strain
	Mechanical strain material property. More...

MaterialProperty< RankTwoTensor > &	_stress
	Stress material property. More...

MaterialProperty< RankTwoTensor > &	_elastic_strain
	Elastic strain material property. More...

const MaterialProperty< RankTwoTensor > &	_extra_stress
	Extra stress tensor. More...

std::vector< const Function * >	_initial_stress_fcn
	initial stress components More...

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


MaterialProperty< RankTwoTensor > &	_creep_strain
	Creep strain variable. More...

const MaterialProperty< RankTwoTensor > &	_creep_strain_old

Detailed Description

Computes the stress of a linear viscoelastic material, using total small strains.

The mechanical strain is decomposed into the elastic strain + the creep strain, the creep strain itself resulting from a spring-dashpot model.

If you need to accomodate other sources of inelastic strains, use a ComputeMultipleInelasticStress material instead, associated with a LinearViscoelasticStressUpdate to represent the creep strain.

Definition at line 30 of file ComputeLinearViscoelasticStress.h.

Constructor & Destructor Documentation

◆ ComputeLinearViscoelasticStress()

ComputeLinearViscoelasticStress::ComputeLinearViscoelasticStress ( const InputParameters & parameters )

Definition at line 36 of file ComputeLinearViscoelasticStress.C.

   : ComputeLinearElasticStress(parameters),
     _creep_strain(declareProperty<RankTwoTensor>(
         isParamValid("base_name") ? _base_name + "_creep_strain" : "creep_strain")),
     _creep_strain_old(getMaterialPropertyOld<RankTwoTensor>(
         isParamValid("base_name") ? _base_name + "_creep_strain" : "creep_strain")),
     _apparent_creep_strain(getMaterialProperty<RankTwoTensor>("apparent_creep_strain")),
     _apparent_elasticity_tensor(getMaterialProperty<RankFourTensor>("apparent_elasticity_tensor")),
     _elasticity_tensor_inv(getMaterialProperty<RankFourTensor>("elasticity_tensor_inv"))
 {
 }

Member Function Documentation

◆ computeQpProperties()

void ComputeStressBase::computeQpProperties ( )

overrideprotectedvirtualinherited

Definition at line 50 of file ComputeStressBase.C.

 {
   computeQpStress();
  
   // Add in extra stress
   _stress[_qp] += _extra_stress[_qp];
 }

◆ computeQpStress()

void ComputeLinearViscoelasticStress::computeQpStress ( )

overrideprotectedvirtual

Compute the stress and store it in the _stress material property for the current quadrature point.

Reimplemented from ComputeLinearElasticStress.

Definition at line 55 of file ComputeLinearViscoelasticStress.C.

 {
   _creep_strain[_qp] =
       _mechanical_strain[_qp] - (_apparent_elasticity_tensor[_qp] * _elasticity_tensor_inv[_qp]) *
                                     (_mechanical_strain[_qp] - _apparent_creep_strain[_qp]);
  
   _elastic_strain[_qp] = _mechanical_strain[_qp] - _creep_strain[_qp];
  
   _stress[_qp] = _elasticity_tensor[_qp] * _elastic_strain[_qp];
  
   _Jacobian_mult[_qp] = _elasticity_tensor[_qp];
 }

◆ initialSetup()

void ComputeLinearElasticStress::initialSetup ( )

overridevirtualinherited

Definition at line 32 of file ComputeLinearElasticStress.C.

 {
   if (hasBlockMaterialProperty<RankTwoTensor>(_base_name + "strain_increment"))
     mooseError("This linear elastic stress calculation only works for small strains; use "
                "ComputeFiniteStrainElasticStress for simulations using incremental and finite "
                "strains.");
 }

◆ initQpStatefulProperties()

void ComputeLinearViscoelasticStress::initQpStatefulProperties ( )

overrideprotectedvirtual

Reimplemented from ComputeStressBase.

Definition at line 49 of file ComputeLinearViscoelasticStress.C.

 {
   _creep_strain[_qp].zero();
 }

◆ validParams()

InputParameters ComputeLinearViscoelasticStress::validParams ( )

static

Definition at line 17 of file ComputeLinearViscoelasticStress.C.

 {
   InputParameters params = ComputeLinearElasticStress::validParams();
   params.addClassDescription("Divides total strain into elastic + creep + eigenstrains");
   params.addParam<std::string>(
       "apparent_creep_strain",
       "apparent_creep_strain",
       "name of the apparent creep strain (defined by a LinearViscoelasticityBase material)");
   params.addParam<std::string>(
       "apparent_elasticity_tensor",
       "apparent_elasticity_tensor",
       "name of the apparent elasticity tensor (defined by a LinearViscoelasticityBase material)");
   params.addParam<std::string>(
       "elasticity_tensor_inv",
       "elasticity_tensor_inv",
       "name of the real compliance tensor (defined by a LinearViscoelasticityBase material)");
   return params;
 }