XFEMRankTwoTensorMarkerUserObject

Mark elements to be cut by XFEM based on a scalar extracted from a RankTwoTensor

Overview

This object is used to mark elements to be cut by XFEM based on a scalar extracted from a specified RankTwoTensor (used to store stresses and strains in SolidMechanics), such as a principal stress or a component of stress. All of the standard scalar types that can be extracted from RankTwoTensors are available. If the scalar exceeds a user-specified threshold, the crack extends into the current element.

The threshold is provided as a coupled variable. This can be specified as either a constant value or as the name of that variable. This is useful for introducing randomness in the strength, by using an AuxVariable that has been initialized with a random initial condition.

The determination of whether an element cracks is based either on the maximum value of the scalar quantity at all of the quadrature points in an element, or on the average value. Cracks are allowed to propagate into new elements that exceed the criterion, or to initiate on specified boundaries.

Example Input File Syntax

[./xfem_marker_uo]
  type = XFEMRankTwoTensorMarkerUserObject
  execute_on = timestep_end
  tensor = stress
  scalar_type = MaxPrincipal
  threshold = 5e+1
  average = true
[../]
(modules/xfem/test/tests/solid_mechanics_basic/crack_propagation_2d.i)

Input Parameters

  • averageFalseShould the tensor quantity be averaged over the quadrature points?

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Should the tensor quantity be averaged over the quadrature points?

  • tensorThe material tensor name.

    C++ Type:std::string

    Controllable:No

    Description:The material tensor name.

  • thresholdThe threshold for crack growth.

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

    Controllable:No

    Description:The threshold for crack growth.

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

  • execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM.

    Default:TIMESTEP_END

    C++ Type:ExecFlagEnum

    Options:FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, 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, the available options include FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM.

  • initiate_on_boundaryPermit cracks to initiate in elements adjacent to specified boundaries

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

    Controllable:No

    Description:Permit cracks to initiate in elements adjacent to specified boundaries

  • point10 0 0Start point for axis used to calculate some cylindrical material tensor quantities

    Default:0 0 0

    C++ Type:libMesh::Point

    Controllable:No

    Description:Start point for axis used to calculate some cylindrical material tensor quantities

  • point20 1 0End point for axis used to calculate some cylindrical material tensor quantities

    Default:0 1 0

    C++ Type:libMesh::Point

    Controllable:No

    Description:End point for axis used to calculate some cylindrical material tensor quantities

  • 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.

  • scalar_typeScalar quantity to be computed from tensor and used as a failure criterion

    C++ Type:MooseEnum

    Options:VonMisesStress, EffectiveStrain, Hydrostatic, L2norm, MaxPrincipal, MidPrincipal, MinPrincipal, VolumetricStrain, FirstInvariant, SecondInvariant, ThirdInvariant, AxialStress, HoopStress, RadialStress, TriaxialityStress, Direction, MaxShear, StressIntensity

    Controllable:No

    Description:Scalar quantity to be computed from tensor and used as a failure criterion

  • secondary_cracksFalseshould secondary cracks be allowed

    Default:False

    C++ Type:bool

    Controllable:No

    Description:should secondary cracks be allowed

  • 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

    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

    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>

    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.

  • 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

    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

    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

    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

    Controllable:No

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

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

    Default:True

    C++ Type:bool

    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

    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

Input Files