ADComputeMeanThermalExpansionEigenstrainBase< compute_stage > Class Template Reference

ADComputeMeanThermalExpansionEigenstrainBase is a base class for computing the thermal expansion eigenstrain according to a temperature-dependent mean thermal expansion defined in a derived class. More...

#include <ADComputeMeanThermalExpansionEigenstrainBase.h>

Inheritance diagram for ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >:

Public Member Functions
	ADComputeMeanThermalExpansionEigenstrainBase (const InputParameters &parameters)

Static Public Member Functions
static InputParameters	validParams ()

Protected Member Functions
virtual void	computeThermalStrain (ADReal &thermal_strain) override
virtual Real	referenceTemperature ()=0
virtual ADReal	meanThermalExpansionCoefficient (const ADReal &temperature)=0
virtual void	computeQpEigenstrain () override
	Compute the eigenstrain and store in _eigenstrain. More...
virtual void	initQpStatefulProperties () override
virtual void	computeQpProperties () override
	ADMaterialProperty (RankTwoTensor) &_eigenstrain
	Stores the current total eigenstrain. More...
ADReal	computeVolumetricStrainComponent (const ADReal volumetric_strain) const
	Helper function for models that compute the eigenstrain based on a volumetric strain. More...

Protected Attributes
	usingComputeThermalExpansionEigenstrainBaseMembers
const ADVariableValue &	_temperature
const ADVariableValue &	_stress_free_temperature
	usingComputeEigenstrainBaseMembers
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...
bool &	_step_zero
	Restartable data to check for the zeroth and first time steps for thermal calculations. More...
	usingMaterialMembers

Detailed Description

template<ComputeStage compute_stage>
class ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >

ADComputeMeanThermalExpansionEigenstrainBase is a base class for computing the thermal expansion eigenstrain according to a temperature-dependent mean thermal expansion defined in a derived class.

This is defined as the total total linear strain ( \(\delta L / L\)) at a given temperature relative to a reference temperature at which \(\delta L = 0\).

Based on: M. Niffenegger and K. Reichlin. The proper use of thermal expansion coefficients in finite element calculations. Nuclear Engineering and Design, 243:356-359, Feb. 2012.

Definition at line 20 of file ADComputeMeanThermalExpansionEigenstrainBase.h.

Constructor & Destructor Documentation

ADComputeMeanThermalExpansionEigenstrainBase()

template<ComputeStage compute_stage>

ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >::ADComputeMeanThermalExpansionEigenstrainBase

(

const InputParameters &

parameters

)

Definition at line 26 of file ADComputeMeanThermalExpansionEigenstrainBase.C.

  : ADComputeThermalExpansionEigenstrainBase<compute_stage>(parameters)
{
}

Member Function Documentation

ADMaterialProperty()

template<ComputeStage compute_stage>

ADComputeEigenstrainBase< compute_stage >::ADMaterialProperty ( RankTwoTensor  ) &

protectedinherited

Stores the current total eigenstrain.

computeQpEigenstrain()

template<ComputeStage compute_stage>

void ADComputeThermalExpansionEigenstrainBase< compute_stage >::computeQpEigenstrain ( )

overrideprotectedvirtualinherited

Compute the eigenstrain and store in _eigenstrain.

Implements ADComputeEigenstrainBase< compute_stage >.

Definition at line 39 of file ADComputeThermalExpansionEigenstrainBase.C.

{
  ADReal thermal_strain = 0.0;
 
  computeThermalStrain(thermal_strain);
 
  _eigenstrain[_qp].zero();
  _eigenstrain[_qp].addIa(thermal_strain);
}

computeQpProperties()

template<ComputeStage compute_stage>

void ADComputeEigenstrainBase< compute_stage >::computeQpProperties ( )

overrideprotectedvirtualinherited

Definition at line 59 of file ADComputeEigenstrainBase.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();
}

computeThermalStrain()

template<ComputeStage compute_stage>

void ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >::computeThermalStrain ( ADReal &  thermal_strain )

overrideprotectedvirtual

Implements ADComputeThermalExpansionEigenstrainBase< compute_stage >.

Definition at line 33 of file ADComputeMeanThermalExpansionEigenstrainBase.C.

{
  const Real reference_temperature = referenceTemperature();
  const ADReal & current_temp = _temperature[_qp];
  const ADReal current_alphabar = meanThermalExpansionCoefficient(current_temp);
  const ADReal thexp_current_temp = current_alphabar * (current_temp - reference_temperature);
 
  // Mean linear thermal expansion coefficient relative to the reference temperature
  // evaluated at stress_free_temperature.  This is
  // \f$\bar{\alpha} = (\delta L(T_{sf}) / L) / (T_{sf} - T_{ref})\f$
  // where \f$T_sf\f$ is the stress-free temperature and \f$T_{ref}\f$ is the reference temperature.
  const ADReal alphabar_stress_free_temperature =
      meanThermalExpansionCoefficient(_stress_free_temperature[_qp]);
  // Thermal expansion relative to the reference temperature evaluated at stress_free_temperature
  // \f$(\delta L(T_sf) / L)\f$, where \f$T_sf\f$ is the stress-free temperature.
  const ADReal thexp_stress_free_temperature =
      alphabar_stress_free_temperature * (_stress_free_temperature[_qp] - referenceTemperature());
 
  // Per M. Niffenegger and K. Reichlin (2012), thermal_strain should be divided
  // by (1.0 + thexp_stress_free_temperature) to account for the ratio of
  // the length at the stress-free temperature to the length at the reference
  // temperature. It can be neglected because it is very close to 1,
  // but we include it for completeness here.
 
  thermal_strain =
      (thexp_current_temp - thexp_stress_free_temperature) / (1.0 + thexp_stress_free_temperature);
}

computeVolumetricStrainComponent()

template<ComputeStage compute_stage>

ADReal ADComputeEigenstrainBase< compute_stage >::computeVolumetricStrainComponent ( const ADReal  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 73 of file ADComputeEigenstrainBase.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()

template<ComputeStage compute_stage>

void ADComputeEigenstrainBase< compute_stage >::initQpStatefulProperties ( )

overrideprotectedvirtualinherited

Reimplemented in ADComputeInstantaneousThermalExpansionFunctionEigenstrain< compute_stage >.

Definition at line 50 of file ADComputeEigenstrainBase.C.

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

meanThermalExpansionCoefficient()

template<ComputeStage compute_stage>

virtual ADReal ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >::meanThermalExpansionCoefficient ( const ADReal &  temperature )

protectedpure virtual

Implemented in ADComputeMeanThermalExpansionFunctionEigenstrain< compute_stage >.

referenceTemperature()

template<ComputeStage compute_stage>

virtual Real ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >::referenceTemperature ( )

protectedpure virtual

Implemented in ADComputeMeanThermalExpansionFunctionEigenstrain< compute_stage >.

validParams()

template<ComputeStage compute_stage>

InputParameters ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >::validParams ( )

static

Definition at line 16 of file ADComputeMeanThermalExpansionEigenstrainBase.C.

{
  InputParameters params = ADComputeThermalExpansionEigenstrainBase<compute_stage>::validParams();
  params.addClassDescription("Base class for models that compute eigenstrain due to mean"
                             "thermal expansion as a function of temperature using AD");
  return params;
}

Referenced by ADComputeMeanThermalExpansionFunctionEigenstrain< compute_stage >::validParams().

Member Data Documentation

_base_name

template<ComputeStage compute_stage>

const std::string ADComputeEigenstrainBase< compute_stage >::_base_name

protectedinherited

Base name prepended to material property name.

Definition at line 50 of file ADComputeEigenstrainBase.h.

_eigenstrain_name

template<ComputeStage compute_stage>

std::string ADComputeEigenstrainBase< compute_stage >::_eigenstrain_name

protectedinherited

Material property name for the eigenstrain tensor.

Definition at line 53 of file ADComputeEigenstrainBase.h.

_step_zero

template<ComputeStage compute_stage>

bool& ADComputeEigenstrainBase< compute_stage >::_step_zero

protectedinherited

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

Definition at line 69 of file ADComputeEigenstrainBase.h.

_stress_free_temperature

template<ComputeStage compute_stage>

const ADVariableValue& ADComputeThermalExpansionEigenstrainBase< compute_stage >::_stress_free_temperature

protectedinherited

Definition at line 55 of file ADComputeThermalExpansionEigenstrainBase.h.

_temperature

template<ComputeStage compute_stage>

const ADVariableValue& ADComputeThermalExpansionEigenstrainBase< compute_stage >::_temperature

protectedinherited

Definition at line 54 of file ADComputeThermalExpansionEigenstrainBase.h.

usingComputeEigenstrainBaseMembers

template<ComputeStage compute_stage>

ADComputeThermalExpansionEigenstrainBase< compute_stage >::usingComputeEigenstrainBaseMembers

protectedinherited

Definition at line 57 of file ADComputeThermalExpansionEigenstrainBase.h.

usingComputeThermalExpansionEigenstrainBaseMembers

template<ComputeStage compute_stage>

ADComputeMeanThermalExpansionEigenstrainBase< compute_stage >::usingComputeThermalExpansionEigenstrainBaseMembers

protected

Definition at line 66 of file ADComputeMeanThermalExpansionEigenstrainBase.h.

usingMaterialMembers

template<ComputeStage compute_stage>

ADComputeEigenstrainBase< compute_stage >::usingMaterialMembers

protectedinherited

Definition at line 71 of file ADComputeEigenstrainBase.h.

---

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

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