TangentialMortarLMMechanicalContact

The TangentialMortarLMMechanicalContact class is used to ensure that the Karush-Kuhn-Tucker conditions of Coulomb frictional contact are satisfied:

where is the coefficient of friction, is the Lagrange multiplier variable representing the contact pressure, is the slip velocity of the secondary face relative to the primary face, and is the Lagrange multiplier variable representing the tangential stress. The above conditions require that either the secondary face is sticking to the primary face, or the secondary face is slipping and the tangential stress is equal in magnitude to the coefficient of friction times the normal contact pressure. Additionally, if the face is slipping, then the force exerted by the secondary face is in the same direction as the slip.

The ncp_function_type parameter specifies the type of nonlinear complimentarity problem (NCP) function to use. The options are either min, which is just the min function, or fb which represents the Fischer-Burmeister function. In our experience, the Fischer-Burmeister function achieves better convergence in the non-linear solve. The c parameter is used to balance the size of the slip velocity and the tangential stress. If the stress is of order 1000, and the velocity is of order 1, then c should be set to 1000 in order to bring components of the NCP function onto the same level and achieve optimal convergence in the non-linear solve.

Ensures that the Karush-Kuhn-Tucker conditions of Coulomb frictional contact are satisfied

Input Parameters

  • contact_pressureThe normal contact pressure; oftentimes this may be a separate lagrange multiplier variable

    C++ Type:NonlinearVariableName

    Controllable:No

    Description:The normal contact pressure; oftentimes this may be a separate lagrange multiplier variable

  • friction_coefficientThe friction coefficient

    C++ Type:double

    Controllable:No

    Description:The friction coefficient

  • 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_disp_yThe y displacement variable on the secondary face

    C++ Type:NonlinearVariableName

    Controllable:No

    Description:The y displacement variable on the secondary face

  • secondary_subdomainThe name of the secondary subdomain.

    C++ Type:SubdomainName

    Controllable:No

    Description:The name of the secondary subdomain.

Required Parameters

  • c1Parameter for balancing the size of the velocity and the pressures

    Default:1

    C++ Type:double

    Controllable:No

    Description:Parameter for balancing the size of the velocity and the pressures

  • compute_lm_residualsTrueWhether to compute Lagrange Multiplier residuals

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Whether to compute Lagrange Multiplier residuals

  • compute_primal_residualsFalseWhether to compute residuals for the primal variable.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether to compute residuals for the primal variable.

  • 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

  • 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_normalsTrueWhether 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:True

    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

  • ncp_function_typefbThe type of the nonlinear complimentarity function; options are min or fb where fb stands for Fischer-Burmeister

    Default:fb

    C++ Type:MooseEnum

    Options:min, fb

    Controllable:No

    Description:The type of the nonlinear complimentarity function; options are min or fb where fb stands for Fischer-Burmeister

  • 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_disp_yThe y displacement variable on the primary face

    C++ Type:NonlinearVariableName

    Controllable:No

    Description:The y displacement variable on the primary face

  • 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.

  • quadratureDEFAULTQuadrature rule to use on mortar segments. For 2D mortar DEFAULT is recommended. For 3D mortar, QUAD meshes are integrated using triangle mortar segments. While DEFAULT quadrature order is typically sufficiently accurate, exact integration of QUAD mortar faces requires SECOND order quadrature for FIRST variables and FOURTH order quadrature for SECOND order variables.

    Default:DEFAULT

    C++ Type:MooseEnum

    Options:DEFAULT, FIRST, SECOND, THIRD, FOURTH

    Controllable:No

    Description:Quadrature rule to use on mortar segments. For 2D mortar DEFAULT is recommended. For 3D mortar, QUAD meshes are integrated using triangle mortar segments. While DEFAULT quadrature order is typically sufficiently accurate, exact integration of QUAD mortar faces requires SECOND order quadrature for FIRST variables and FOURTH order quadrature for SECOND order variables.

  • secondary_variablePrimal variable on secondary surface.

    C++ Type:VariableName

    Controllable:No

    Description:Primal variable on secondary surface.

  • variableThe name of the lagrange multiplier variable that this constraint is applied to. This parameter may not be supplied in the case of using penalty methods for example

    C++ Type:NonlinearVariableName

    Controllable:No

    Description:The name of the lagrange multiplier variable that this constraint is applied to. This parameter may not be supplied in the case of using penalty methods for example

Optional Parameters

  • 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.

  • 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

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

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

    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>

    Controllable:No

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

  • matrix_tagssystemThe tag for the matrices this Kernel should fill

    Default:system

    C++ Type:MultiMooseEnum

    Options:nontime, system

    Controllable:No

    Description:The tag for the matrices this Kernel should fill

  • vector_tagsnontimeThe tag for the vectors this Kernel should fill

    Default:nontime

    C++ Type:MultiMooseEnum

    Options:nontime, time

    Controllable:No

    Description:The tag for the vectors this Kernel should fill

Tagging Parameters

Input Files