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

    Options:

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

  • friction_coefficientThe friction coefficient

    C++ Type:double

    Options:

    Description:The friction coefficient

  • primary_boundaryThe name of the primary boundary sideset.

    C++ Type:BoundaryName

    Options:

    Description:The name of the primary boundary sideset.

  • primary_subdomainThe name of the primary subdomain.

    C++ Type:SubdomainName

    Options:

    Description:The name of the primary subdomain.

  • secondary_boundaryThe name of the secondary boundary sideset.

    C++ Type:BoundaryName

    Options:

    Description:The name of the secondary boundary sideset.

  • secondary_disp_yThe y displacement variable on the secondary face

    C++ Type:NonlinearVariableName

    Options:

    Description:The y displacement variable on the secondary face

  • secondary_subdomainThe name of the secondary subdomain.

    C++ Type:SubdomainName

    Options:

    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

    Options:

    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

    Options:

    Description:Whether to compute Lagrange Multiplier residuals

  • compute_primal_residualsFalseWhether to compute residuals for the primal variable.

    Default:False

    C++ Type:bool

    Options:

    Description:Whether to compute residuals for the primal variable.

  • 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

    Options:

    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

    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

    Options:

    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

    Options:

    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

    Options:

    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

    Options:

    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.

  • secondary_variablePrimal variable on secondary surface.

    C++ Type:VariableName

    Options:

    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

    Options:

    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>

    Options:

    Description:Adds user-defined labels for accessing object parameters via control logic.

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Options:

    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

    Options:

    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

    Options:

    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

    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.

Advanced Parameters

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

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

    Options:

    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>

    Options:

    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

    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

    Description:The tag for the vectors this Kernel should fill

Tagging Parameters

Input Files