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ComputeMeanThermalExpansionEigenstrainBase Class Referenceabstract

ComputeMeanThermalExpansionEigenstrainBase 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 <ComputeMeanThermalExpansionEigenstrainBase.h>

Inheritance diagram for ComputeMeanThermalExpansionEigenstrainBase:
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Public Member Functions

 ComputeMeanThermalExpansionEigenstrainBase (const InputParameters &parameters)
 

Protected Member Functions

virtual void computeThermalStrain (Real &thermal_strain, Real &instantaneous_cte) override
 
virtual Real referenceTemperature ()=0
 
virtual Real meanThermalExpansionCoefficient (const Real temperature)=0
 
virtual Real meanThermalExpansionCoefficientDerivative (const Real temperature)=0
 
virtual void computeQpEigenstrain () override
 

Protected Attributes

const VariableValue & _temperature
 
MaterialProperty< RankTwoTensor > & _deigenstrain_dT
 
const VariableValue & _stress_free_temperature
 

Detailed Description

ComputeMeanThermalExpansionEigenstrainBase 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 31 of file ComputeMeanThermalExpansionEigenstrainBase.h.

Constructor & Destructor Documentation

◆ ComputeMeanThermalExpansionEigenstrainBase()

ComputeMeanThermalExpansionEigenstrainBase::ComputeMeanThermalExpansionEigenstrainBase ( const InputParameters &  parameters)

Definition at line 23 of file ComputeMeanThermalExpansionEigenstrainBase.C.

26 {
27 }
ComputeThermalExpansionEigenstrainBase(const InputParameters &parameters)

Member Function Documentation

◆ computeQpEigenstrain()

void ComputeThermalExpansionEigenstrainBase::computeQpEigenstrain ( )
overrideprotectedvirtualinherited

Definition at line 37 of file ComputeThermalExpansionEigenstrainBase.C.

38 {
39  Real thermal_strain = 0.0;
40  Real instantaneous_cte = 0.0;
41 
42  computeThermalStrain(thermal_strain, instantaneous_cte);
43 
44  _eigenstrain[_qp].zero();
45  _eigenstrain[_qp].addIa(thermal_strain);
46 
47  _deigenstrain_dT[_qp].zero();
48  _deigenstrain_dT[_qp].addIa(instantaneous_cte);
49 }
virtual void computeThermalStrain(Real &thermal_strain, Real &instantaneous_cte)=0

◆ computeThermalStrain()

void ComputeMeanThermalExpansionEigenstrainBase::computeThermalStrain ( Real &  thermal_strain,
Real &  instantaneous_cte 
)
overrideprotectedvirtual

Implements ComputeThermalExpansionEigenstrainBase.

Definition at line 30 of file ComputeMeanThermalExpansionEigenstrainBase.C.

32 {
33  const Real small = libMesh::TOLERANCE;
34 
35  const Real reference_temperature = referenceTemperature();
36  const Real & current_temp = _temperature[_qp];
37  const Real current_alphabar = meanThermalExpansionCoefficient(current_temp);
38  const Real thexp_current_temp = current_alphabar * (current_temp - reference_temperature);
39 
40  // Mean linear thermal expansion coefficient relative to the reference temperature
41  // evaluated at stress_free_temperature. This is
42  // \f$\bar{\alpha} = (\delta L(T_{sf}) / L) / (T_{sf} - T_{ref})\f$
43  // where \f$T_sf\f$ is the stress-free temperature and \f$T_{ref}\f$ is the reference temperature.
44  const Real alphabar_stress_free_temperature =
46  // Thermal expansion relative to the reference temperature evaluated at stress_free_temperature
47  // \f$(\delta L(T_sf) / L)\f$, where \f$T_sf\f$ is the stress-free temperature.
48  const Real thexp_stress_free_temperature =
49  alphabar_stress_free_temperature * (_stress_free_temperature[_qp] - referenceTemperature());
50 
51  // Per M. Niffenegger and K. Reichlin (2012), thermal_strain should be divided
52  // by (1.0 + thexp_stress_free_temperature) to account for the ratio of
53  // the length at the stress-free temperature to the length at the reference
54  // temperature. It can be neglected because it is very close to 1,
55  // but we include it for completeness here.
56 
57  thermal_strain =
58  (thexp_current_temp - thexp_stress_free_temperature) / (1.0 + thexp_stress_free_temperature);
59 
60  const Real dalphabar_dT = meanThermalExpansionCoefficientDerivative(current_temp);
61  const Real numerator = dalphabar_dT * (current_temp - reference_temperature) + current_alphabar;
62  const Real denominator =
63  1.0 +
64  alphabar_stress_free_temperature * (_stress_free_temperature[_qp] - reference_temperature);
65  if (denominator < small)
66  mooseError("Denominator too small in thermal strain calculation");
67  instantaneous_cte = numerator / denominator;
68 }
virtual Real meanThermalExpansionCoefficientDerivative(const Real temperature)=0
virtual Real meanThermalExpansionCoefficient(const Real temperature)=0

◆ meanThermalExpansionCoefficient()

virtual Real ComputeMeanThermalExpansionEigenstrainBase::meanThermalExpansionCoefficient ( const Real  temperature)
protectedpure virtual

◆ meanThermalExpansionCoefficientDerivative()

virtual Real ComputeMeanThermalExpansionEigenstrainBase::meanThermalExpansionCoefficientDerivative ( const Real  temperature)
protectedpure virtual

◆ referenceTemperature()

virtual Real ComputeMeanThermalExpansionEigenstrainBase::referenceTemperature ( )
protectedpure virtual

Member Data Documentation

◆ _deigenstrain_dT

MaterialProperty<RankTwoTensor>& ComputeThermalExpansionEigenstrainBase::_deigenstrain_dT
protectedinherited

◆ _stress_free_temperature

const VariableValue& ComputeThermalExpansionEigenstrainBase::_stress_free_temperature
protectedinherited

◆ _temperature

const VariableValue& ComputeThermalExpansionEigenstrainBase::_temperature
protectedinherited

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