EBSDReader

Load and manage DREAM.3D EBSD data files for running simulations on reconstructed microstructures.

The EBSDReader user object reads in data from electron backscatter diffraction (EBSD) to set initial conditions for phase field simulations. EBSD identifies the grain and phase structure of a sample, as well as the crystal structure and the crystal orientation. The EBSDReader reads in this information from a specially formatted data file and reconstructs the microstructure. It accomplishes this by setting the initial conditions for all the phase field variables. In addition, it stores the crystal structure and orientation information by use by the phase field and mechanics models.

Note that the EBSDReader does not mesh the microstructure**, but rather sets phase field variable initial conditions. To reconstruct a mesh of the microstructure, we recommend using OOF.

Average orientation of a grain

Euler angles are not the best for representing the orientation of a grain because they suffer from gimbal lock. Therefore, we use quaternions to compute the average orientation of the grain. Firstly, the Euler angles are converted to quaternions. Next, we segregate the quaternions into different bins with the parameter "bins" specifying the number of bins. We then perform a weighted average of the quaternions with weights of each quaternion corresponds to size of the bin in which it resides. The average quaternion is then converted to Euler angle representation.

Various weighted averages can be performed by raising power of the weights corresponding to each quaternion. The parameter "L_norm" allows us to raise the power of the weights according to the positive integer assigned to it. By default, the value of "L_norm" is set to 1, computing the simple weighted average of the quaternions.

Input Parameters

  • L_norm1Specifies the type of average the user intends to perform

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Specifies the type of average the user intends to perform

  • bins20Number of bins to segregate quaternions

    Default:20

    C++ Type:unsigned int

    Unit:(no unit assumed)

    Controllable:No

    Description:Number of bins to segregate quaternions

  • custom_columns0Number of additional custom data columns to read from the EBSD file

    Default:0

    C++ Type:unsigned int

    Unit:(no unit assumed)

    Controllable:No

    Description:Number of additional custom data columns to read from the EBSD file

  • ebsd_meshgeneratorSpecify the name of the EBSDMeshGenerator. The EBSDReader can autodetect this, if only one such MeshGenerator exists.

    C++ Type:std::string

    Unit:(no unit assumed)

    Controllable:No

    Description:Specify the name of the EBSDMeshGenerator. The EBSDReader can autodetect this, if only one such MeshGenerator exists.

  • execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.

    Default:TIMESTEP_END

    C++ Type:ExecFlagEnum

    Unit:(no unit assumed)

    Options:NONE, INITIAL, LINEAR, NONLINEAR_CONVERGENCE, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM

    Controllable:No

    Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.

  • 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

    Unit:(no unit assumed)

    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.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Optional Parameters

  • allow_duplicate_execution_on_initialFalseIn 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:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    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).

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

    C++ Type:std::vector<std::string>

    Unit:(no unit assumed)

    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

    Unit:(no unit assumed)

    Controllable:Yes

    Description:Set the enabled status of the MooseObject.

  • execution_order_group0Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.

    Default:0

    C++ Type:int

    Unit:(no unit assumed)

    Controllable:No

    Description:Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.

  • force_postauxFalseForces the UserObject to be executed in POSTAUX

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Forces the UserObject to be executed in POSTAUX

  • force_preauxFalseForces the UserObject to be executed in PREAUX

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Forces the UserObject to be executed in PREAUX

  • force_preicFalseForces the UserObject to be executed in PREIC during initial setup

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Forces the UserObject to be executed in PREIC during initial setup

  • 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

    Unit:(no unit assumed)

    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

EBSD Data File Format

The EBSDReader user object reads in a data file taken from EBSD data. The file should have the following format:


# Header:    Marmot Input File

# Date:      19-Jul-2013 00:23:55

#
# Column 1:  Euler angle "phi1" (in radians)

# Column 2:  Euler angle "PHI" (in radians)

# Column 3:  Euler angle "phi2" (in radians)

# Column 4:  x-coordinate (in microns)

# Column 5:  y-coordinate (in microns)

# Column 6:  z-coordinate (in microns)

# Column 7:  grain number (integer)

# Column 8:  phase number (integer)

# Column 9:  symmetry class (from TSL)

#
# Phase 1:   Nickel (symmetry class = 43)

# Number of Grains in Phase 1:  111

#
# X_Min:      0.000000

# X_Max:      32.000000

# X_step:     0.250000

# X_Dim:      128

#
# Y_Min:      0.000000

# Y_Max:      32.000000

# Y_step:     0.250000

# Y_Dim:      128

#
# Z_Min:      0.000000

# Z_Max:      0.000000

# Z_step:     0.000000

# Z_Dim:      0

#
2.48663 1.84098 5.50548 0.12500 0.12500 0.00000 0 1 43
2.48663 1.84098 5.50548 0.12500 0.37500 0.00000 0 1 43
.
.
.

The open source code Dream3D has the option to output in this format using the _"Write INL File"_ filter. Note that the data must be on a square grid rather than a hex grid.

The EBSDReader supports additional custom data columns.