PenaltyFrictionUserObject

Description

The PenaltyFrictionUserObject object computes tangential pressures due to Coulomb friction by looping over mortar segments. The accumulated tangential slip is penalized by a penalty_friction factor. As the slip accumulates, the frictional pressure(s) saturates at the Coulomb limit. Note that a high enough value of the penalty_friction value is required to obtain realistic frictional pressure; otherwise, the tangential model will underpredict frictional forces. That is, higher values of the penalty_friction parameter will more accurately predict the stick and slip Coulomb behavior at the expense of worsening the convergence behavior.

The tangential pressure (or pressures for a three-dimensional problem) generated by this object contains Jacobian information as a consequence of using automatic differentiation objects. These pressures are directly applied on the contacting surfaces by TangentialMortarMechanicalContact. That is, the tangential contact pressure values computed by this object serve a purpose analogous to the Lagrange multipliers when exact enforcement is used (see ComputeFrictionalForceLMMechanicalContact). This object is set up automatically when using the contact action ContactAction.

Input Parameters

  • disp_xThe x displacement variable

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

    Controllable:No

    Description:The x displacement variable

  • disp_yThe y displacement variable

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

    Controllable:No

    Description:The y displacement variable

  • friction_coefficientThe friction coefficient ruling Coulomb friction equations.

    C++ Type:double

    Controllable:No

    Description:The friction coefficient ruling Coulomb friction equations.

  • penaltyThe penalty factor for normal interaction.

    C++ Type:double

    Controllable:No

    Description:The penalty factor for normal interaction.

  • primary_boundaryThe name of the primary boundary sideset.

    C++ Type:BoundaryName

    Controllable:No

    Description:The name of the primary boundary sideset.

  • primary_subdomainThe name of the primary subdomain.

    C++ Type:SubdomainName

    Controllable:No

    Description:The name of the primary subdomain.

  • secondary_boundaryThe name of the secondary boundary sideset.

    C++ Type:BoundaryName

    Controllable:No

    Description:The name of the secondary boundary sideset.

  • secondary_subdomainThe name of the secondary subdomain.

    C++ Type:SubdomainName

    Controllable:No

    Description:The name of the secondary subdomain.

  • secondary_variablePrimal variable on secondary surface.

    C++ Type:VariableName

    Controllable:No

    Description:Primal variable on secondary surface.

Required Parameters

  • correct_edge_droppingFalseWhether to enable correct edge dropping treatment for mortar constraints. When disabled any Lagrange Multiplier degree of freedom on a secondary element without full primary contributions will be set (strongly) to 0.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether to enable correct edge dropping treatment for mortar constraints. When disabled any Lagrange Multiplier degree of freedom on a secondary element without full primary contributions will be set (strongly) to 0.

  • debug_meshFalseWhether this constraint is going to enable mortar segment mesh debug information. An exodusfile will be generated if the user sets this flag to true

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether this constraint is going to enable mortar segment mesh debug information. An exodusfile will be generated if the user sets this flag to true

  • disp_zThe z displacement variable

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

    Controllable:No

    Description:The z displacement variable

  • ghost_higher_d_neighborsFalseWhether we should ghost higher-dimensional neighbors. This is necessary when we are doing second order mortar with finite volume primal variables, because in order for the method to be second order we must use cell gradients, which couples in the neighbor cells.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether we should ghost higher-dimensional neighbors. This is necessary when we are doing second order mortar with finite volume primal variables, because in order for the method to be second order we must use cell gradients, which couples in the neighbor cells.

  • ghost_point_neighborsFalseWhether we should ghost point neighbors of secondary face elements, and consequently also their mortar interface couples.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether we should ghost point neighbors of secondary face elements, and consequently also their mortar interface couples.

  • interpolate_normalsFalseWhether to interpolate the nodal normals (e.g. classic idea of evaluating field at quadrature points). If this is set to false, then non-interpolated nodal normals will be used, and then the _normals member should be indexed with _i instead of _qp

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether to interpolate the nodal normals (e.g. classic idea of evaluating field at quadrature points). If this is set to false, then non-interpolated nodal normals will be used, and then the _normals member should be indexed with _i instead of _qp

  • minimum_projection_angle40Parameter to control which angle (in degrees) is admissible for the creation of mortar segments. If set to a value close to zero, very oblique projections are allowed, which can result in mortar segments solving physics not meaningfully, and overprojection of primary nodes onto the mortar segment mesh in extreme cases. This parameter is mostly intended for mortar mesh debugging purposes in two dimensions.

    Default:40

    C++ Type:double

    Controllable:No

    Description:Parameter to control which angle (in degrees) is admissible for the creation of mortar segments. If set to a value close to zero, very oblique projections are allowed, which can result in mortar segments solving physics not meaningfully, and overprojection of primary nodes onto the mortar segment mesh in extreme cases. This parameter is mostly intended for mortar mesh debugging purposes in two dimensions.

  • penalty_frictionThe penalty factor for frictional interaction. If not provide, the normal penalty factor is also used for the frictional problem.

    C++ Type:double

    Controllable:No

    Description:The penalty factor for frictional interaction. If not provide, the normal penalty factor is also used for the frictional problem.

  • periodicFalseWhether this constraint is going to be used to enforce a periodic condition. This has the effect of changing the normals vector for projection from outward to inward facing

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether this constraint is going to be used to enforce a periodic condition. This has the effect of changing the normals vector for projection from outward to inward facing

  • primary_variablePrimal variable on primary surface. If this parameter is not provided then the primary variable will be initialized to the secondary variable

    C++ Type:VariableName

    Controllable:No

    Description:Primal variable on primary surface. If this parameter is not provided then the primary variable will be initialized to the secondary variable

  • 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.

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

  • use_displaced_meshTrueWhether 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:True

    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