Displacement About Axis

Implements a boundary condition that enforces rotationaldisplacement around an axis on a boundary

Description

The boundary condition class DisplacementAboutAxis applies a rotating displacement to the specified mesh surface according to the user defined rotation function. The boundary condition is always applied to the displaced mesh. The rotation function can be given in either radians or in angles, and an axis of rotation can be specified with the axis_origin and axis_direction parameters. By default, the function defines the rotation, but if the angular_velocity parameter is set, it allows for the function to define an angular velocity instead of a total rotation angle.

The rotating displacement value at the current node is calculated according to Eq. (1): (1) where is the translation matrix for axes of rotation not centered at the coordinate system origin, and , , and are rotation matrices about the , , and coordinate system axes, respectively.

Example Input File Syntax

[./top_x]
  type = DisplacementAboutAxis
  boundary = 2
  function = '0.1*t'
  angle_units = degrees
  axis_origin = '10. 10. 10.'
  axis_direction = '0 -1.0 1.0'
  component = 0
  variable = disp_x
[../]
(moose/modules/solid_mechanics/test/tests/torque_reaction/torque_reaction_cylinder.i)

A Function is required to prescribe either the total rotation or angular velocity of the DisplacementAboutAxis boundary condition applied to the mesh. Either the name of another function defined elsewhere or a parsed function is used as the argument for the function input parameter in the DisplacementAboutAxis block. In this example, a parsed function is used.

Input Parameters

  • angle_unitsThe units of the angle of rotation. Choices are:degrees radians

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:degrees, radians

    Controllable:No

    Description:The units of the angle of rotation. Choices are:degrees radians

  • axis_directionDirection of the axis of rotation

    C++ Type:libMesh::VectorValue<double>

    Unit:(no unit assumed)

    Controllable:No

    Description:Direction of the axis of rotation

  • axis_originOrigin of the axis of rotation

    C++ Type:libMesh::VectorValue<double>

    Unit:(no unit assumed)

    Controllable:No

    Description:Origin of the axis of rotation

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

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

    Unit:(no unit assumed)

    Controllable:No

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

  • componentThe component for the rotational displacement

    C++ Type:int

    Unit:(no unit assumed)

    Controllable:No

    Description:The component for the rotational displacement

  • displacementsThe string of displacements suitable for the problem statement

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The string of displacements suitable for the problem statement

  • functionThe function providing the total angle of rotation or the angular velocity.

    C++ Type:FunctionName

    Unit:(no unit assumed)

    Controllable:No

    Description:The function providing the total angle of rotation or the angular velocity.

  • variableThe name of the variable that this residual object operates on

    C++ Type:NonlinearVariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the variable that this residual object operates on

Required Parameters

  • angular_velocityFalseIf true interprets the function value as an angular velocity

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:If true interprets the function value as an angular velocity

  • diag_save_inThe name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

  • presetTrueWhether or not to preset the BC (apply the value before the solve begins).

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether or not to preset the BC (apply the value before the solve begins).

  • save_inThe name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

Optional Parameters

  • absolute_value_vector_tagsThe tags for the vectors this residual object should fill with the absolute value of the residual contribution

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The tags for the vectors this residual object should fill with the absolute value of the residual contribution

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The extra tags for the matrices this Kernel should fill

  • extra_vector_tagsThe extra tags for the vectors this Kernel should fill

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The extra tags for the vectors this Kernel should fill

  • matrix_tagssystem timeThe tag for the matrices this Kernel should fill

    Default:system time

    C++ Type:MultiMooseEnum

    Unit:(no unit assumed)

    Options:nontime, system, time

    Controllable:No

    Description:The tag for the matrices this Kernel should fill

  • vector_tagsresidualThe tag for the vectors this Kernel should fill

    Default:residual

    C++ Type:MultiMooseEnum

    Unit:(no unit assumed)

    Options:nontime, time, residual

    Controllable:No

    Description:The tag for the vectors this Kernel should fill

Tagging Parameters

  • 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.

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

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    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

    Unit:(no unit assumed)

    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

    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