PolycrystalVoronoi

The PolycrystalVoronoi UserObject either generates a set of random points or reads a set of grain centroids from a file and performs a Voronoi tesslation to produce a grain structure. The number of grains may be set by the user but a suitable number must be chosen that is supported by the mesh resolution and grain boundary width. Once the grain structure has been generated, a coloring algorithm is used to assign order parameters to grains so that a reduced number of order parameters may be used. Typical numbers are given here:

DimensionRecommended OPs
2D8
3D25

See Polycrystal Initial Conditions for more information.

Typical usage in an input file:

[UserObjects]
  [./voronoi]
    type = PolycrystalVoronoi
    grain_num = 100 # Number of grains
    rand_seed = 10
  [../]
  [./grain_tracker]
    type = GrainTracker
    threshold = 0.2
    connecting_threshold = 0.08
    compute_halo_maps = true # Only necessary for displaying HALOS
  [../]
[]
[ICs]
  [./PolycrystalICs]
    [./PolycrystalColoringIC]
      polycrystal_ic_uo = voronoi
    [../]
  [../]
[]
(modules/phase_field/examples/grain_growth/grain_growth_2D_graintracker.i)

Description and Syntax

Random Voronoi tesselation polycrystal (used by PolycrystalVoronoiAction)

Input Parameters

  • variableArray of coupled variables

    C++ Type:std::vector

    Options:

    Description:Array of coupled variables

Required Parameters

  • var_name_baseArray of coupled variables (base_name)

    C++ Type:std::string

    Options:

    Description:Array of coupled variables (base_name)

  • enable_var_coloringFalseInstruct the Postprocessor to populate the variable index map.

    Default:False

    C++ Type:bool

    Options:

    Description:Instruct the Postprocessor to populate the variable index map.

  • output_adjacency_matrixFalseOutput the Grain Adjacency Matrix used in the coloring algorithms. Additionally, the grain to OP assignments will be printed

    Default:False

    C++ Type:bool

    Options:

    Description:Output the Grain Adjacency Matrix used in the coloring algorithms. Additionally, the grain to OP assignments will be printed

  • grain_num0Number of grains being represented by the order parameters

    Default:0

    C++ Type:unsigned int

    Options:

    Description:Number of grains being represented by the order parameters

  • file_nameFile containing grain centroids, if file_name is provided, the centroids from the file will be used.

    C++ Type:FileName

    Options:

    Description:File containing grain centroids, if file_name is provided, the centroids from the file will be used.

  • connecting_thresholdThe threshold for which an existing feature may be extended (defaults to "threshold")

    C++ Type:double

    Options:

    Description:The threshold for which an existing feature may be extended (defaults to "threshold")

  • use_less_than_threshold_comparisonTrueControls whether features are defined to be less than or greater than the threshold value.

    Default:True

    C++ Type:bool

    Options:

    Description:Controls whether features are defined to be less than or greater than the threshold value.

  • columnar_3DFalse3D microstructure will be columnar in the z-direction?

    Default:False

    C++ Type:bool

    Options:

    Description:3D microstructure will be columnar in the z-direction?

  • rand_seed0The random seed

    Default:0

    C++ Type:unsigned int

    Options:

    Description:The random seed

  • op_numArray of coupled variables (num_name)

    C++ Type:unsigned int

    Options:

    Description:Array of coupled variables (num_name)

  • flood_entity_typeELEMENTALDetermines whether the flood algorithm runs on nodes or elements

    Default:ELEMENTAL

    C++ Type:MooseEnum

    Options:NODAL ELEMENTAL

    Description:Determines whether the flood algorithm runs on nodes or elements

  • compute_var_to_feature_mapFalseInstruct the Postprocessor to compute the active vars to features map

    Default:False

    C++ Type:bool

    Options:

    Description:Instruct the Postprocessor to compute the active vars to features map

  • threshold0.5The threshold value for which a new feature may be started

    Default:0.5

    C++ Type:double

    Options:

    Description:The threshold value for which a new feature may be started

  • execute_onINITIALThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.

    Default:INITIAL

    C++ Type:ExecFlagEnum

    Options:NONE INITIAL LINEAR NONLINEAR TIMESTEP_END TIMESTEP_BEGIN FINAL CUSTOM

    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, FINAL, CUSTOM.

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

    C++ Type:std::vector

    Options:

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

  • coloring_algorithmjpThe grain neighbor graph coloring algorithm to use: "jp" (DEFAULT) Jones and Plassmann, an efficient coloring algorithm, "power" an alternative stochastic algorithm, "greedy", a greedy assignment algorithm with stochastic updates to guarantee a valid coloring, "bt", a back tracking algorithm that produces good distributions but may experience exponential run time in the worst case scenario (works well on medium to large 2D problems)

    Default:jp

    C++ Type:MooseEnum

    Options:jp power greedy bt

    Description:The grain neighbor graph coloring algorithm to use: "jp" (DEFAULT) Jones and Plassmann, an efficient coloring algorithm, "power" an alternative stochastic algorithm, "greedy", a greedy assignment algorithm with stochastic updates to guarantee a valid coloring, "bt", a back tracking algorithm that produces good distributions but may experience exponential run time in the worst case scenario (works well on medium to large 2D problems)

  • compute_halo_mapsFalseInstruct the Postprocessor to communicate proper halo information to all ranks

    Default:False

    C++ Type:bool

    Options:

    Description:Instruct the Postprocessor to communicate proper halo information to all ranks

Optional Parameters

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Options:

    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

    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.

  • 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

    Options:

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

  • use_single_mapTrueDetermine whether information is tracked per coupled variable or consolidated into one (default: true)

    Default:True

    C++ Type:bool

    Options:

    Description:Determine whether information is tracked per coupled variable or consolidated into one (default: true)

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

    C++ Type:std::vector

    Options:

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

  • allow_duplicate_execution_on_initialTrueIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).

    Default:True

    C++ Type:bool

    Options:

    Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).

  • condense_map_infoFalseDetermines whether we condense all the node values when in multimap mode (default: false)

    Default:False

    C++ Type:bool

    Options:

    Description:Determines whether we condense all the node values when in multimap mode (default: false)

  • use_global_numberingTrueDetermine whether or not global numbers are used to label features on multiple maps (default: true)

    Default:True

    C++ Type:bool

    Options:

    Description:Determine whether or not global numbers are used to label features on multiple maps (default: true)

  • force_preauxFalseForces the GeneralUserObject to be executed in PREAUX

    Default:False

    C++ Type:bool

    Options:

    Description:Forces the GeneralUserObject to be executed in PREAUX

Advanced Parameters

Input Files

Child Objects