XFEMRankTwoTensorMarkerUserObject

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

Description

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 TensorMechanics), 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.

Input Parameters

  • thresholdThe threshold for crack growth.

    C++ Type:std::vector

    Options:

    Description:The threshold for crack growth.

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

    Default:False

    C++ Type:bool

    Options:

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

  • tensorThe material tensor name.

    C++ Type:std::string

    Options:

    Description:The material tensor name.

Required Parameters

  • 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

    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

    Options:

    Description:should secondary cracks be allowed

  • initiate_on_boundaryPermit cracks to initiate in elements adjacent to specified boundaries

    C++ Type:std::vector

    Options:

    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

    Options:

    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

    Options:

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

  • execute_onTIMESTEP_ENDThe 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:TIMESTEP_END

    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.

  • blockThe list of block ids (SubdomainID) that this object will be applied

    C++ Type:std::vector

    Options:

    Description:The list of block ids (SubdomainID) that this object will be applied

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.

  • 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_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

    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).

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Options:

    Description:The seed for the master random number generator

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

    Default:True

    C++ Type:bool

    Options:

    Description:Determines whether this object is calculated using an implicit or explicit form

Advanced Parameters

Input Files