MaterialStdVectorRealGradientAux

Extracts a component of a material's std::vector<RealGradient> to an aux variable. If the std::vector is not of sufficient size then zero is returned

Converting a field from the material system, here a component of the gradient of a material property, to a variable may be desirable for several reasons: to match the format expected by certain kernels (thus lagging the field between time steps) or for output/testing/debugging.

This is particularly useful to examine anisotropic material properties. For output purposes only, an alternative is to use the output_properties argument of the Material or specify output_material_properties in the parameters of the desired output type nested in the [Outputs] block. This AuxKernel is used in the back-end by these parameters.

note

The AD system currently does not support auxiliary variables. If you convert material properties, which do support automatic differentiation, to auxiliary variables, the derivatives will be ignored.

Example syntax

In this example, the MaterialStdVectorRealGradientAux is used to examine gradients of the force densities between particles in a phase field simulation.

  [./df01]
    type = MaterialStdVectorRealGradientAux
    variable = df01
    index = 0
    component = 1
    property = force_density
  [../]
  [./df11]
    type = MaterialStdVectorRealGradientAux
    variable = df11
    index = 1
    component = 1
    property = force_density
  [../]
  [./df00]
    type = MaterialStdVectorRealGradientAux
    variable = df00
    index = 0
    component = 0
    property = force_density
  [../]
  [./df10]
    type = MaterialStdVectorRealGradientAux
    variable = df10
    index = 1
    component = 0
    property = force_density
  [../]

Input Parameters

propertyThe scalar material property name
C++ Type:MaterialPropertyName
Controllable:No
Description:The scalar material property name
variableThe name of the variable that this object applies to
C++ Type:AuxVariableName
Controllable:No
Description:The name of the variable that this object applies to

Required Parameters

blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:The list of blocks (ids or names) that this object will be applied
boundaryThe list of boundaries (ids or names) from the mesh where this object applies
C++ Type:std::vector<BoundaryName>
Controllable:No
Description:The list of boundaries (ids or names) from the mesh where this object applies
check_boundary_restrictedTrueWhether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh
Default:True
C++ Type:bool
Controllable:No
Description:Whether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh
component0The gradient component to be extracted for this kernel
Default:0
C++ Type:unsigned int
Controllable:No
Description:The gradient component to be extracted for this kernel
execute_onLINEAR TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS, PRE_DISPLACE.
Default:LINEAR TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS, PRE_DISPLACE
Controllable:No
Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS, PRE_DISPLACE.
factor1The factor by which to multiply your material property for visualization
Default:1
C++ Type:double
Controllable:No
Description:The factor by which to multiply your material property for visualization
index0The index to consider for this kernel
Default:0
C++ Type:unsigned int
Controllable:No
Description:The index to consider for this kernel
offset0The offset to add to your material property for visualization
Default:0
C++ Type:double
Controllable:No
Description:The offset to add to your material property for visualization
prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Controllable:No
Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Controllable:No
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
Controllable:No
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

(../moose/modules/phase_field/test/tests/rigidbodymotion/grain_motion_fauxGT.i)

# test file for showing reaction forces between particles
[GlobalParams]
  var_name_base = eta
  op_num = 2
[]

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 5
  nz = 0
  xmax = 50
  ymax = 25
  zmax = 0
  elem_type = QUAD4
  uniform_refine = 1
[]

[Variables]
  [./c]
    order = FIRST
    family = LAGRANGE
  [../]
  [./w]
    order = FIRST
    family = LAGRANGE
  [../]
  [./eta0]
  [../]
  [./eta1]
  [../]
[]

[Kernels]
  [./c_res]
    type = SplitCHParsed
    variable = c
    f_name = F
    kappa_name = kappa_c
    coupled_variables = 'eta0 eta1'
    w = w
  [../]
  [./w_res]
    type = SplitCHWRes
    variable = w
    mob_name = M
  [../]
  [./time]
    type = CoupledTimeDerivative
    variable = w
    v = c
  [../]
  [./motion]
    type = MultiGrainRigidBodyMotion
    variable = w
    c = c
    v = 'eta0 eta1'
    grain_force = grain_force
    grain_tracker_object = grain_center
    grain_volumes = grain_volumes
  [../]
  [./eta0_dot]
    type = TimeDerivative
    variable = eta0
  [../]
  [./vadv_eta]
    type = SingleGrainRigidBodyMotion
    variable = eta0
    c = c
    v = 'eta0 eta1'
    grain_force = grain_force
    grain_tracker_object = grain_center
    grain_volumes = grain_volumes
    op_index = 0
  [../]
  [./acint_eta0]
    type = ACInterface
    variable = eta0
    mob_name = M
    #coupled_variables = c
    kappa_name = kappa_eta
  [../]
  [./acbulk_eta0]
    type = AllenCahn
    variable = eta0
    mob_name = M
    f_name = F
    coupled_variables = 'c eta1'
  [../]
  [./eta1_dot]
    type = TimeDerivative
    variable = eta1
  [../]
  [./vadv_eta1]
    type = SingleGrainRigidBodyMotion
    variable = eta1
    c = c
    v = 'eta0 eta1'
    op_index = 1
    grain_force = grain_force
    grain_tracker_object = grain_center
    grain_volumes = grain_volumes
  [../]
  [./acint_eta1]
    type = ACInterface
    variable = eta1
    mob_name = M
    #coupled_variables = c
    kappa_name = kappa_eta
  [../]
  [./acbulk_eta1]
    type = AllenCahn
    variable = eta1
    mob_name = M
    f_name = F
    coupled_variables = 'c eta0'
  [../]
[]

[Materials]
  [./pfmobility]
    type = GenericConstantMaterial
    prop_names = 'M    kappa_c  kappa_eta'
    prop_values = '1.0  0.5      0.5'
  [../]
  [./free_energy]
    type = DerivativeParsedMaterial
    property_name = F
    coupled_variables = 'c eta0 eta1'
    constant_names = 'barr_height  cv_eq'
    constant_expressions = '0.1          1.0e-2'
    expression = 16*barr_height*(c-cv_eq)^2*(1-cv_eq-c)^2+eta0*(1-eta0)*c+eta1*(1-eta1)*c
    derivative_order = 2
  [../]
  [./force_density]
    type = ForceDensityMaterial
    c = c
    etas ='eta0 eta1'
  [../]
[]

[AuxVariables]
  [./bnds]
  [../]
  [./df00]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./df01]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./df10]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./df11]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./unique_grains]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./var_indices]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./centroids]
    order = CONSTANT
    family = MONOMIAL
  [../]
[]

[AuxKernels]
  [./bnds]
    type = BndsCalcAux
    variable = bnds
    var_name_base = eta
    op_num = 2
    v = 'eta0 eta1'
  [../]
  [./df01]
    type = MaterialStdVectorRealGradientAux
    variable = df01
    index = 0
    component = 1
    property = force_density
  [../]
  [./df11]
    type = MaterialStdVectorRealGradientAux
    variable = df11
    index = 1
    component = 1
    property = force_density
  [../]
  [./df00]
    type = MaterialStdVectorRealGradientAux
    variable = df00
    index = 0
    component = 0
    property = force_density
  [../]
  [./df10]
    type = MaterialStdVectorRealGradientAux
    variable = df10
    index = 1
    component = 0
    property = force_density
  [../]
  [./unique_grains]
    type = FeatureFloodCountAux
    variable = unique_grains
    flood_counter = grain_center
    field_display = UNIQUE_REGION
    execute_on = 'initial timestep_end'
  [../]
  [./var_indices]
    type = FeatureFloodCountAux
    variable = var_indices
    flood_counter = grain_center
    field_display = VARIABLE_COLORING
    execute_on = 'initial timestep_end'
  [../]
  [./centroids]
    type = FeatureFloodCountAux
    variable = centroids
    execute_on = 'initial timestep_end'
    field_display = CENTROID
    flood_counter = grain_center
  [../]
[]

[ICs]
  [./ic_eta0]
    int_width = 1.0
    x1 = 20.0
    y1 = 0.0
    radius = 14.0
    outvalue = 0.0
    variable = eta0
    invalue = 1.0
    type = SmoothCircleIC
  [../]
  [./IC_eta1]
    int_width = 1.0
    x1 = 30.0
    y1 = 25.0
    radius = 14.0
    outvalue = 0.0
    variable = eta1
    invalue = 1.0
    type = SmoothCircleIC
  [../]
  [./ic_c]
    type = SpecifiedSmoothCircleIC
    invalue = 1.0
    outvalue = 0.1
    int_width = 1.0
    x_positions = '20.0 30.0 '
    z_positions = '0.0 0.0 '
    y_positions = '0.0 25.0 '
    radii = '14.0 14.0'
    3D_spheres = false
    variable = c
    block = 0
  [../]
[]

[VectorPostprocessors]
  [./forces]
    type = GrainForcesPostprocessor
    grain_force = grain_force
  [../]
  [./grain_volumes]
    type = FeatureVolumeVectorPostprocessor
    flood_counter = grain_center
    execute_on = 'initial timestep_begin'
  [../]
[]

[UserObjects]
  [./grain_center]
    type = FauxGrainTracker
    outputs = none
    compute_var_to_feature_map = true
    execute_on = 'initial timestep_begin'
    variable = 'eta0 eta1'
  [../]
  [./grain_force]
    type = ComputeGrainForceAndTorque
    execute_on = 'linear nonlinear'
    grain_data = grain_center
    force_density = force_density
    c = c
    etas = 'eta0 eta1'
  [../]
[]

[Preconditioning]
  [./SMP]
    type = SMP
    full = true
  [../]
[]

[Executioner]
  type = Transient
  scheme = bdf2
  solve_type = NEWTON
  petsc_options_iname = '-pc_type -ksp_gmres_restart -sub_ksp_type -sub_pc_type -pc_asm_overlap'
  petsc_options_value = 'asm         31   preonly   lu      1'
  l_max_its = 30
  l_tol = 1.0e-4
  nl_rel_tol = 1.0e-10
  start_time = 0.0
  num_steps = 1
  dt = 0.1
[]

[Outputs]
  exodus = true
  csv = true
[]