NEML Thermal Expansion Eigenstrain

Use a model in the NEML library to compute thermal expansion

Thermal Eigenstrain Obtained from NEML

This material model provides an interface to use the Nuclear Engineering Material model Library (NEML) developed by Argonne National Laboratory to provide thermal expansion eigenstrains. This model would typically be used together with the NEMLStress model, the documentation of which provides more details on integration with that library.

NEML permits the definition of complex material constitutive models, the details of which are defined in an XML file that is independent of the MOOSE input file. The required inputs for this model on the MOOSE side simply provide the location of the XML file, which contains a database of potentially multiple material models, and the name of the model within that database to be used. This model computes the eigenstrain induced by thermal expansion.

Input Parameters

databasePath to NEML XML database.
C++ Type:FileName
Options:
Description:Path to NEML XML database.
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
Options:
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.
modelModel name in NEML database.
C++ Type:std::string
Options:
Description:Model name in NEML database.
stress_free_temperatureReference temperature at which there is no thermal expansion for thermal eigenstrain calculation
C++ Type:std::vector<VariableName>
Options:
Description:Reference temperature at which there is no thermal expansion for thermal eigenstrain calculation

Required Parameters

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
Options:
Description:Optional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases
blockThe list of block ids (SubdomainID) that this object will be applied
C++ Type:std::vector<SubdomainName>
Options:
Description:The list of block ids (SubdomainID) that this object will be applied
boundaryThe list of boundary IDs from the mesh where this boundary condition applies
C++ Type:std::vector<BoundaryName>
Options:
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 MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
Default:True
C++ Type:bool
Options:
Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
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 computeQpProperties() 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
Options:NONE, ELEMENT, SUBDOMAIN
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 computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
temperatureCoupled temperature
C++ Type:std::vector<VariableName>
Options:
Description:Coupled temperature

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Options:
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
Description:Set the enabled status of the MooseObject.
implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Options:
Description:Determines whether this object is calculated using an implicit or explicit form
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Options:
Description:The seed for the master random number generator
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
Options:
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.

Advanced Parameters

output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)
C++ Type:std::vector<std::string>
Options:
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<OutputName>
Options:
Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object

Outputs Parameters

Input Files

(test/tests/neml_simple/le_stress_thermal.i)

References

(test/tests/neml_simple/le_stress_thermal.i)

[GlobalParams]
  displacements = 'disp_x disp_y disp_z'
[]

[Variables]
  [disp_x]
  []
  [disp_y]
  []
  [disp_z]
  []
[]

[Mesh]
  type = GeneratedMesh
  dim = 3
[]

[Kernels]
  [TensorMechanics]
  []
[]

[AuxVariables]
  [strain_xx]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_zz]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_xy]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yz]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_xz]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_xx]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_zz]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_xy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yz]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_xz]
    order = CONSTANT
    family = MONOMIAL
  []
  [temp]
    initial_condition = 0.0
  []
[]

[AuxKernels]
  [strain_xx]
    type = RankTwoAux
    rank_two_tensor = total_strain
    variable = strain_xx
    index_i = 0
    index_j = 0
    execute_on = timestep_end
  []
  [strain_yy]
    type = RankTwoAux
    rank_two_tensor = total_strain
    variable = strain_yy
    index_i = 1
    index_j = 1
    execute_on = timestep_end
  []
  [strain_zz]
    type = RankTwoAux
    rank_two_tensor = total_strain
    variable = strain_zz
    index_i = 2
    index_j = 2
    execute_on = timestep_end
  []
  [strain_xy]
    type = RankTwoAux
    rank_two_tensor = total_strain
    variable = strain_xy
    index_i = 0
    index_j = 1
    execute_on = timestep_end
  []
  [strain_yz]
    type = RankTwoAux
    rank_two_tensor = total_strain
    variable = strain_yz
    index_i = 1
    index_j = 2
    execute_on = timestep_end
  []
  [strain_xz]
    type = RankTwoAux
    rank_two_tensor = total_strain
    variable = strain_xz
    index_i = 0
    index_j = 1
    execute_on = timestep_end
  []
  [stress_xx]
    type = RankTwoAux
    rank_two_tensor = stress
    variable = stress_xx
    index_i = 0
    index_j = 0
    execute_on = timestep_end
  []
  [stress_yy]
    type = RankTwoAux
    rank_two_tensor = stress
    variable = stress_yy
    index_i = 1
    index_j = 1
    execute_on = timestep_end
  []
  [stress_zz]
    type = RankTwoAux
    rank_two_tensor = stress
    variable = stress_zz
    index_i = 2
    index_j = 2
    execute_on = timestep_end
  []
  [stress_xy]
    type = RankTwoAux
    rank_two_tensor = stress
    variable = stress_xy
    index_i = 0
    index_j = 1
    execute_on = timestep_end
  []
  [stress_yz]
    type = RankTwoAux
    rank_two_tensor = stress
    variable = stress_yz
    index_i = 1
    index_j = 2
    execute_on = timestep_end
  []
  [stress_xz]
    type = RankTwoAux
    rank_two_tensor = stress
    variable = stress_xz
    index_i = 0
    index_j = 1
    execute_on = timestep_end
  []
  [temp]
    type = FunctionAux
    variable = temp
    function = temperature
  []
[]

[BCs]
  [fx]
    type = DirichletBC
    variable = disp_x
    boundary = 4
    value = 0.0
  []

  [fy]
    type = DirichletBC
    variable = disp_y
    boundary = 1
    value = 0.0
  []

  [fz]
    type = DirichletBC
    variable = disp_z
    boundary = 0
    value = 0.0
  []

  [pz]
    type = DirichletBC
    variable = disp_z
    boundary = 5
    value = 0.0
  []
[]

[Functions]
  [temperature]
    type = PiecewiseLinear
    x = '0 1'
    y = '0 100.0'
  []
[]

[Materials]
  [strain]
    type = ComputeSmallStrain
    eigenstrain_names = thermal
  []

  [stress]
    type = NEMLStress
    database = 'examples.xml'
    model = 'simple_example'
    temperature = temp
  []

  [thermal_strain]
    type = NEMLThermalExpansionEigenstrain
    database = 'examples.xml'
    model = 'simple_example'
    temperature = temp
    eigenstrain_name = thermal
    stress_free_temperature = 0.0
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = True
  []
[]

[Postprocessors]
  [stress_xx]
    type = ElementAverageValue
    variable = stress_xx
  []
  [stress_yy]
    type = ElementAverageValue
    variable = stress_yy
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_zz
  []
  [stress_xy]
    type = ElementAverageValue
    variable = stress_xy
  []
  [stress_xz]
    type = ElementAverageValue
    variable = stress_xz
  []
  [stress_yz]
    type = ElementAverageValue
    variable = stress_yz
  []
[]

[Executioner]
  type = Transient
  solve_type = 'NEWTON'

  l_max_its = 2
  l_tol = 1e-3
  nl_max_its = 10
  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-8

  petsc_options = '-snes_converged_reason -ksp_converged_reason -snes_linesearch_monitor'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  end_time = 1.0
  dt = 1.0
[]

[Outputs]
  exodus = false
  console = true
  csv = true
[]

Input Parameters
Input Files
References