ComputeEigenstrain Class Reference

ComputeEigenstrain computes an Eigenstrain that is a function of a single variable defined by a base tensor and a scalar function defined in a Derivative Material. More...

#include <ComputeEigenstrain.h>

Inheritance diagram for ComputeEigenstrain:

Public Member Functions
	ComputeEigenstrain (const InputParameters &parameters)

Static Public Member Functions
static InputParameters	validParams ()

Protected Member Functions
virtual void	computeQpEigenstrain ()
	Compute the eigenstrain and store in _eigenstrain. More...
virtual void	initQpStatefulProperties ()
virtual void	computeQpProperties ()
Real	computeVolumetricStrainComponent (const Real volumetric_strain) const
	Helper function for models that compute the eigenstrain based on a volumetric strain. More...

Protected Attributes
const MaterialProperty< Real > &	_prefactor
RankTwoTensor	_eigen_base_tensor
const std::string	_base_name
	Base name prepended to material property name. More...
std::string	_eigenstrain_name
	Material property name for the eigenstrain tensor. More...
MaterialProperty< RankTwoTensor > &	_eigenstrain
	Stores the current total eigenstrain. More...
bool &	_step_zero
	Restartable data to check for the zeroth and first time steps for thermal calculations. More...

Detailed Description

ComputeEigenstrain computes an Eigenstrain that is a function of a single variable defined by a base tensor and a scalar function defined in a Derivative Material.

Definition at line 25 of file ComputeEigenstrain.h.

Constructor & Destructor Documentation

ComputeEigenstrain()

ComputeEigenstrain::ComputeEigenstrain

(

const InputParameters &

parameters

)

Definition at line 28 of file ComputeEigenstrain.C.

  : ComputeEigenstrainBase(parameters), _prefactor(getMaterialProperty<Real>("prefactor"))
{
  _eigen_base_tensor.fillFromInputVector(getParam<std::vector<Real>>("eigen_base"));
}

Member Function Documentation

computeQpEigenstrain()

void ComputeEigenstrain::computeQpEigenstrain ( )

protectedvirtual

Compute the eigenstrain and store in _eigenstrain.

Implements ComputeEigenstrainBase.

Definition at line 35 of file ComputeEigenstrain.C.

{
  // Define Eigenstrain
  _eigenstrain[_qp] = _eigen_base_tensor * _prefactor[_qp];
}

Referenced by ComputeVariableEigenstrain::computeQpEigenstrain().

computeQpProperties()

void ComputeEigenstrainBase::computeQpProperties ( )

protectedvirtualinherited

Definition at line 49 of file ComputeEigenstrainBase.C.

{
  if (_t_step >= 1)
    _step_zero = false;
 
  // Skip the eigenstrain calculation in step zero because no solution is computed during
  // the zeroth step, hence computing the eigenstrain in the zeroth step would result in
  // an incorrect calculation of mechanical_strain, which is stateful.
  if (!_step_zero)
    computeQpEigenstrain();
}

computeVolumetricStrainComponent()

Real ComputeEigenstrainBase::computeVolumetricStrainComponent ( const Real  volumetric_strain ) const

protectedinherited

Helper function for models that compute the eigenstrain based on a volumetric strain.

This function computes the diagonal components of the eigenstrain tensor as logarithmic strains.

Parameters

volumetric_strain

The current volumetric strain to be applied

Returns

Current strain in one direction due to volumetric strain, expressed as a logarithmic strain

Definition at line 62 of file ComputeEigenstrainBase.C.

{
  // The engineering strain in a given direction is:
  // epsilon_eng = cbrt(volumetric_strain + 1.0) - 1.0
  //
  // We need to provide this as a logarithmic strain to be consistent with the strain measure
  // used for finite strain:
  // epsilon_log = log(1.0 + epsilon_eng)
  //
  // This can be simplified down to a more direct form:
  // epsilon_log = log(cbrt(volumetric_strain + 1.0))
  // or:
  // epsilon_log = (1/3) log(volumetric_strain + 1.0)
 
  return std::log(volumetric_strain + 1.0) / 3.0;
}

initQpStatefulProperties()

void ComputeEigenstrainBase::initQpStatefulProperties ( )

protectedvirtualinherited

Reimplemented in ComputeReducedOrderEigenstrain.

Definition at line 41 of file ComputeEigenstrainBase.C.

{
  // This property can be promoted to be stateful by other models that use it,
  // so it needs to be initalized.
  _eigenstrain[_qp].zero();
}

validParams()

InputParameters ComputeEigenstrain::validParams ( )

static

Definition at line 17 of file ComputeEigenstrain.C.

{
  InputParameters params = ComputeEigenstrainBase::validParams();
  params.addClassDescription("Computes a constant Eigenstrain");
  params.addRequiredParam<std::vector<Real>>(
      "eigen_base", "Vector of values defining the constant base tensor for the Eigenstrain");
  params.addParam<MaterialPropertyName>(
      "prefactor", 1.0, "Name of material defining the variable dependence");
  return params;
}

Referenced by ComputeVariableEigenstrain::validParams().

Member Data Documentation

_base_name

const std::string ComputeEigenstrainBase::_base_name

protectedinherited

Base name prepended to material property name.

Definition at line 41 of file ComputeEigenstrainBase.h.

Referenced by ComputeReducedOrderEigenstrain::ComputeReducedOrderEigenstrain().

_eigen_base_tensor

RankTwoTensor ComputeEigenstrain::_eigen_base_tensor

protected

Definition at line 37 of file ComputeEigenstrain.h.

Referenced by ComputeEigenstrain(), and computeQpEigenstrain().

_eigenstrain

MaterialProperty<RankTwoTensor>& ComputeEigenstrainBase::_eigenstrain

protectedinherited

Stores the current total eigenstrain.

Definition at line 47 of file ComputeEigenstrainBase.h.

Referenced by computeQpEigenstrain(), ComputeEigenstrainFromInitialStress::computeQpEigenstrain(), ComputeVariableBaseEigenStrain::computeQpEigenstrain(), ComputeReducedOrderEigenstrain::computeQpEigenstrain(), ComputeEigenstrainBase::initQpStatefulProperties(), and ComputeReducedOrderEigenstrain::initQpStatefulProperties().

_eigenstrain_name

std::string ComputeEigenstrainBase::_eigenstrain_name

protectedinherited

Material property name for the eigenstrain tensor.

Definition at line 44 of file ComputeEigenstrainBase.h.

_prefactor

const MaterialProperty<Real>& ComputeEigenstrain::_prefactor

protected

Definition at line 35 of file ComputeEigenstrain.h.

Referenced by computeQpEigenstrain().

_step_zero

bool& ComputeEigenstrainBase::_step_zero

protectedinherited

Restartable data to check for the zeroth and first time steps for thermal calculations.

Definition at line 60 of file ComputeEigenstrainBase.h.

Referenced by ComputeEigenstrainBase::computeQpProperties().

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

• tensor_mechanics/include/materials/ComputeEigenstrain.h
• tensor_mechanics/src/materials/ComputeEigenstrain.C