# UOvar element = document.getElementById("moose-equation-95e44789-a78c-48f6-b52b-67a0ec6c323f");katex.render("_2", element, {displayMode:false,throwOnError:false}); Fuel Thermal Expansion MATPRO Eigenstrain

Calculates eigenstrain due to thermal expansion in UO2 fuel using MATPRO correlations

## Description

This class, UO2ThermalExpansionMatproEigenstrain, calculates the strain due to thermal expansion using correlations from MATPRO. The correlation in MATPRO is a function of Plutonium content in the fuel, the fraction of the fuel that is in a molten state, and the temperature of the fuel. These correlations are based on a reference temperature of 300K, but this class permits the use of arbitrary values for the stress-free temperature. In Bison we assume a Pu content of 0.0 and molten fuel fraction of 0.0 in computing the thermal expansion of the UO fuel.

This material uses the MATPRO fthexp function to determine the thermal expansion strains based on temperature (Allison et al., 1993).

## Example Input Syntax


[./thermal_strain]
type = UO2ThermalExpansionMatproEigenstrain
block = 0
temperature = temperature
stress_free_temperature = 240
eigenstrain_name = thermal_eigenstrain
[../]
(test/tests/tensor_mechanics/uo2_eigenstrains/uo2_matpro_cte.i)

The eigenstrain_name parameter value must also be set for the strain calculator, and an example parameter setting is shown below:


[./strain]
type = ComputeAxisymmetricRZIncrementalStrain
block = 0
eigenstrain_names = thermal_eigenstrain
[../]
(test/tests/tensor_mechanics/uo2_eigenstrains/uo2_matpro_cte.i)

## Input Parameters

• stress_free_temperatureStress free temperature (does not produce thermal expansion stress) for thermal eigenstrain calculation; if unknown, this value is commonly set to be equal to the initial temperature.

C++ Type:double

Description:Stress free temperature (does not produce thermal expansion stress) for thermal eigenstrain calculation; if unknown, this value is commonly set to be equal to the initial temperature.

• temperatureCoupled temperature, in K

C++ Type:std::vector

Description:Coupled temperature, in K

• eigenstrain_nameMaterial property name for the eigenstrain tensor computed by this model. IMPORTANT: The name of this property must also be provided to the strain calculator.

C++ Type:std::string

Description:Material property name for the eigenstrain tensor computed by this model. IMPORTANT: The name of this property must also be provided to the strain calculator.

### Required Parameters

• boundaryThe list of boundary IDs from the mesh where this boundary condition applies

C++ Type:std::vector

Description:The list of boundary IDs from the mesh where this boundary condition applies

• computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

Default:True

C++ Type:bool

Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

• blockThe list of block ids (SubdomainID) that this object will be applied

C++ Type:std::vector

Description:The list of block ids (SubdomainID) that this object will be applied

• base_nameOptional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases

C++ Type:std::string

Description:Optional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases

### Optional Parameters

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Description:Set the enabled status of the MooseObject.

• use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Default:False

C++ Type:bool

Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Description:Adds user-defined labels for accessing object parameters via control logic.

• seed0The seed for the master random number generator

Default:0

C++ Type:unsigned int

Description:The seed for the master random number generator

• implicitTrueDetermines whether this object is calculated using an implicit or explicit form

Default:True

C++ Type:bool

Description:Determines whether this object is calculated using an implicit or explicit form

• constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

Default:NONE

C++ Type:MooseEnum

Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

• output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)

C++ Type:std::vector

Description:List of material properties, from this material, to output (outputs must also be defined to an output type)

• outputsnone Vector of output names were you would like to restrict the output of variables(s) associated with this object

Default:none

C++ Type:std::vector

Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object

## References

1. C. M. Allison, G. A. Berna, R. Chambers, E. W. Coryell, K. L. Davis, D. L. Hagrman, D. T. Hagrman, N. L. Hampton, J. K. Hohorst, R. E. Mason, M. L. McComas, K. A. McNeil, R. L. Miller, C. S. Olsen, G. A. Reymann, and L. J. Siefken. SCDAP/RELAP5/MOD3.1 code manual, volume IV: MATPROâ€“A library of materials properties for light-water-reactor accident analysis. Technical Report NUREG/CR-6150, EGG-2720, Idaho National Engineering Laboratory, 1993.[BibTeX]