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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 28 of file ComputeMeanThermalExpansionEigenstrainBase.h.

Constructor & Destructor Documentation

ComputeMeanThermalExpansionEigenstrainBase::ComputeMeanThermalExpansionEigenstrainBase ( const InputParameters &  parameters)

Definition at line 20 of file ComputeMeanThermalExpansionEigenstrainBase.C.

23 {
24 }
ComputeThermalExpansionEigenstrainBase(const InputParameters &parameters)

Member Function Documentation

void ComputeThermalExpansionEigenstrainBase::computeQpEigenstrain ( )
overrideprotectedvirtualinherited

Definition at line 34 of file ComputeThermalExpansionEigenstrainBase.C.

35 {
36  Real thermal_strain = 0.0;
37  Real instantaneous_cte = 0.0;
38 
39  computeThermalStrain(thermal_strain, instantaneous_cte);
40 
41  _eigenstrain[_qp].zero();
42  _eigenstrain[_qp].addIa(thermal_strain);
43 
44  _deigenstrain_dT[_qp].zero();
45  _deigenstrain_dT[_qp].addIa(instantaneous_cte);
46 }
virtual void computeThermalStrain(Real &thermal_strain, Real &instantaneous_cte)=0
void ComputeMeanThermalExpansionEigenstrainBase::computeThermalStrain ( Real &  thermal_strain,
Real &  instantaneous_cte 
)
overrideprotectedvirtual

Implements ComputeThermalExpansionEigenstrainBase.

Definition at line 27 of file ComputeMeanThermalExpansionEigenstrainBase.C.

29 {
30  const Real small = libMesh::TOLERANCE;
31 
32  const Real reference_temperature = referenceTemperature();
33  const Real & current_temp = _temperature[_qp];
34  const Real current_alphabar = meanThermalExpansionCoefficient(current_temp);
35  const Real thexp_current_temp = current_alphabar * (current_temp - reference_temperature);
36 
37  // Mean linear thermal expansion coefficient relative to the reference temperature
38  // evaluated at stress_free_temperature. This is
39  // \f$\bar{\alpha} = (\delta L(T_{sf}) / L) / (T_{sf} - T_{ref})\f$
40  // where \f$T_sf\f$ is the stress-free temperature and \f$T_{ref}\f$ is the reference temperature.
41  const Real alphabar_stress_free_temperature =
43  // Thermal expansion relative to the reference temperature evaluated at stress_free_temperature
44  // \f$(\delta L(T_sf) / L)\f$, where \f$T_sf\f$ is the stress-free temperature.
45  const Real thexp_stress_free_temperature =
46  alphabar_stress_free_temperature * (_stress_free_temperature[_qp] - referenceTemperature());
47 
48  // Per M. Niffenegger and K. Reichlin (2012), thermal_strain should be divided
49  // by (1.0 + thexp_stress_free_temperature) to account for the ratio of
50  // the length at the stress-free temperature to the length at the reference
51  // temperature. It can be neglected because it is very close to 1,
52  // but we include it for completeness here.
53 
54  thermal_strain =
55  (thexp_current_temp - thexp_stress_free_temperature) / (1.0 + thexp_stress_free_temperature);
56 
57  const Real dalphabar_dT = meanThermalExpansionCoefficientDerivative(current_temp);
58  const Real numerator = dalphabar_dT * (current_temp - reference_temperature) + current_alphabar;
59  const Real denominator =
60  1.0 +
61  alphabar_stress_free_temperature * (_stress_free_temperature[_qp] - reference_temperature);
62  if (denominator < small)
63  mooseError("Denominator too small in thermal strain calculation");
64  instantaneous_cte = numerator / denominator;
65 }
virtual Real meanThermalExpansionCoefficientDerivative(const Real temperature)=0
virtual Real meanThermalExpansionCoefficient(const Real temperature)=0
virtual Real ComputeMeanThermalExpansionEigenstrainBase::meanThermalExpansionCoefficient ( const Real  temperature)
protectedpure virtual
virtual Real ComputeMeanThermalExpansionEigenstrainBase::meanThermalExpansionCoefficientDerivative ( const Real  temperature)
protectedpure virtual
virtual Real ComputeMeanThermalExpansionEigenstrainBase::referenceTemperature ( )
protectedpure virtual

Member Data Documentation

MaterialProperty<RankTwoTensor>& ComputeThermalExpansionEigenstrainBase::_deigenstrain_dT
protectedinherited
const VariableValue& ComputeThermalExpansionEigenstrainBase::_stress_free_temperature
protectedinherited
const VariableValue& ComputeThermalExpansionEigenstrainBase::_temperature
protectedinherited

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