Layered1DFrictionalForce

Determines and applies frictional forces between fuel and cladding for one-dimensional simulations.

Description

Layered1DFrictionalForce computes frictional forces between fuel and cladding interfaces by assessing the normal contact forces from a mechanical contact constraint and the relative out-of-plane strain time increment difference between the fuel and cladding layers. Since this user object is nodal, when elemental quantities are required for computations (e.g. stress components), those are obtained by querying an elemental user object Layered1DContactInterfaceStress.

Two instances of the Layered1DFrictionalForce user object must be created; one on the fuel interface and another one on the cladding interface. The contact pressure values only reside on the secondary side, so the cladding user object obtains the contact pressure from the fuel user object. Similarly, two instances of the elemental user object Layered1DContactInterfaceStress are run on the fuel and cladding blocks to obtain the out of plane elasticity coefficient and geometric information for the application of internal forces.

This user object needs to be provided to the layered one-dimensional tensor mechanics action for each block so that the interaction forces are added to the system, i.e. layer_friction_user_object = 1DFriction_secondary, in which 1DFriction_secondary is the nodal user object computing frictional forces on the secondary (fuel) surface.

Usage of this object requires the employment of general frictionless mechanical contact, which is typically done through the contact action. The contact pressure resulting from frictionless mechanical contact is passed to the layered 1D frictional objects as an input to determine whether the surfaces are sliding or sticking.

commentnote:This capability only works for serial runs
commentnote:Number of layers

This object assumes that the number of layers provided as input correspond to those that can have mechanical contact, i.e. plenum layers can be disregarded.

commentnote:Axial dimensions of fuel and rod

direction_min and direction_max correspond to the physical locations of the top and bottom layers of fuel and cladding, respectively, considering the rod layers that can be into mechanical contact. direction_min and direction_max do not refer to the absolute minimum and maximum of the blocks. On the contrary, the fuel pin geometry that reads from the mesh in layered simulations will assume that the minimum value for the fuel area would be: direction_min - 0.5 * slice_height.

Example Input Syntax

User object input for secondary side (fuel)

[UserObjects<<<{"href": "../../syntax/UserObjects/index.html"}>>>]
  [1DFriction_secondary]
    type = Layered1DFrictionalForce<<<{"description": "Determines and applies frictional forces between fuel and cladding for one-dimensional simulations.", "href": "Layered1DFrictionalForce.html"}>>>
    force_postaux<<<{"description": "Forces the UserObject to be executed in POSTAUX"}>>> = true
    contact_pressure<<<{"description": "The contact pressure variable defining interaction between fuel and cladding."}>>> = contact_pressure
    direction<<<{"description": "The direction of the layers."}>>> = y
    boundary<<<{"description": "The list of boundaries (ids or names) from the mesh where this object applies"}>>> = pellet_outer_radial_surface
    num_layers<<<{"description": "The number of layers."}>>> = 10
    interface_oop_stress_provider_fuel<<<{"description": "Out of plane stress increment on interface provider for fuel."}>>> = 1DContactStressOOP_fuel
    interface_oop_stress_provider_cladding<<<{"description": "Out of plane stress increment on interface provider for cladding."}>>> = 1DContactStressOOP_cladding
    is_secondary_side<<<{"description": "Whether this user object acts on a secondary surface. Otherwise, another user object providing contact pressure is required."}>>> = true
    tangential_pressure<<<{"description": "The auxiliary variable that holds the tangential contact pressure generated by the layered 1D friction user objects."}>>> = tangential_contact_pressure_aux
    friction_coefficient<<<{"description": "Coefficient of friction applied to contact interface."}>>> = 0.2
    thickness<<<{"description": "Layer thickness. Assumed constant in this user object."}>>> = 0.01
    penalty_factor<<<{"description": "Penalty factor used to enforce the sticking conditions on out of plane strain increments for fuel and cladding. The default value has demonstrated to work well in typical simulation scenarios."}>>> = 1.0e13
    # If we do not provide the numbers below, it will look at the mesh, in all blocks to set the layer number. Then, it will
    # be wrong because the cladding has more height and won't be able to identify layers in the fuel.
    direction_min<<<{"description": "Minimum coordinate along 'direction' that bounds the layers"}>>> = 0.00917
    direction_max<<<{"description": "Maximum coordinate along 'direction' that bounds the layers"}>>> = 0.11591

    scalar_var_name_base_fuel<<<{"description": "Fuel scalar variables for axisymmetric 1D problem (base_name)"}>>> = scalar_strain_yy_fuel
    scalar_num_variable_fuel<<<{"description": "Fuel scalar variables for axisymmetric 1D problem (num_name)"}>>> = 10
    scalar_var_name_base_cladding<<<{"description": "Cladding scalar variables for axisymmetric 1D problem (base_name)"}>>> = scalar_strain_yy_clad
    scalar_num_variable_cladding<<<{"description": "Cladding scalar variables for axisymmetric 1D problem (num_name)"}>>> = 10

    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'LINEAR NONLINEAR'
  []
[]
(examples/1.5D_rodlet_10pellets/1_5D_friction.i)

User object input for primary side (cladding)

[UserObjects<<<{"href": "../../syntax/UserObjects/index.html"}>>>]
  [1DFriction_primary]
    type = Layered1DFrictionalForce<<<{"description": "Determines and applies frictional forces between fuel and cladding for one-dimensional simulations.", "href": "Layered1DFrictionalForce.html"}>>>
    force_postaux<<<{"description": "Forces the UserObject to be executed in POSTAUX"}>>> = true
    contact_pressure<<<{"description": "The contact pressure variable defining interaction between fuel and cladding."}>>> = contact_pressure
    direction<<<{"description": "The direction of the layers."}>>> = y

    boundary<<<{"description": "The list of boundaries (ids or names) from the mesh where this object applies"}>>> = clad_inside_right
    num_layers<<<{"description": "The number of layers."}>>> = 10
    # If we do not provide the numbers below, it will look at the mesh, in all blocks to set the layer number. Then, it will
    # be wrong because the cladding has more height and won't be able to identify layers in the fuel.
    direction_min<<<{"description": "Minimum coordinate along 'direction' that bounds the layers"}>>> = 0.00917
    direction_max<<<{"description": "Maximum coordinate along 'direction' that bounds the layers"}>>> = 0.11591

    interface_oop_stress_provider_fuel<<<{"description": "Out of plane stress increment on interface provider for fuel."}>>> = 1DContactStressOOP_fuel
    interface_oop_stress_provider_cladding<<<{"description": "Out of plane stress increment on interface provider for cladding."}>>> = 1DContactStressOOP_cladding
    is_secondary_side<<<{"description": "Whether this user object acts on a secondary surface. Otherwise, another user object providing contact pressure is required."}>>> = false
    secondary_side_frictional_user_object<<<{"description": "Secondary side frictional user object used to provide contact pressure."}>>> = 1DFriction_secondary
    friction_coefficient<<<{"description": "Coefficient of friction applied to contact interface."}>>> = 0.2
    thickness<<<{"description": "Layer thickness. Assumed constant in this user object."}>>> = 0.01
    penalty_factor<<<{"description": "Penalty factor used to enforce the sticking conditions on out of plane strain increments for fuel and cladding. The default value has demonstrated to work well in typical simulation scenarios."}>>> = 1.0e13
    scalar_var_name_base_fuel<<<{"description": "Fuel scalar variables for axisymmetric 1D problem (base_name)"}>>> = scalar_strain_yy_fuel
    scalar_num_variable_fuel<<<{"description": "Fuel scalar variables for axisymmetric 1D problem (num_name)"}>>> = 10
    scalar_var_name_base_cladding<<<{"description": "Cladding scalar variables for axisymmetric 1D problem (base_name)"}>>> = scalar_strain_yy_clad
    scalar_num_variable_cladding<<<{"description": "Cladding scalar variables for axisymmetric 1D problem (num_name)"}>>> = 10

    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'LINEAR NONLINEAR'
  []
[]
(examples/1.5D_rodlet_10pellets/1_5D_friction.i)

Input Parameters

  • contact_pressureThe contact pressure variable defining interaction between fuel and cladding.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The contact pressure variable defining interaction between fuel and cladding.

  • directionThe direction of the layers.

    C++ Type:MooseEnum

    Options:x, y, z

    Controllable:No

    Description:The direction of the layers.

  • friction_coefficientCoefficient of friction applied to contact interface.

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Coefficient of friction applied to contact interface.

  • interface_oop_stress_provider_claddingOut of plane stress increment on interface provider for cladding.

    C++ Type:UserObjectName

    Controllable:No

    Description:Out of plane stress increment on interface provider for cladding.

  • interface_oop_stress_provider_fuelOut of plane stress increment on interface provider for fuel.

    C++ Type:UserObjectName

    Controllable:No

    Description:Out of plane stress increment on interface provider for fuel.

  • num_layersThe number of layers.

    C++ Type:unsigned int

    Controllable:No

    Description:The number of layers.

  • scalar_out_of_plane_strain_claddingCladding scalar variables for axisymmetric 1D problem

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Cladding scalar variables for axisymmetric 1D problem

  • scalar_out_of_plane_strain_fuelFuel scalar variables for axisymmetric 1D problem

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Fuel scalar variables for axisymmetric 1D problem

  • thicknessLayer thickness. Assumed constant in this user object.

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Layer thickness. Assumed constant in this user object.

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

  • boundaryThe list of boundaries (ids or names) from the mesh where this object applies

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

    Controllable:No

    Description:The list of boundaries (ids or names) from the mesh where this object applies

  • boundsThe 'bounding' positions of the layers i.e.: '0, 1.2, 3.7, 4.2' will mean 3 layers between those positions.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The 'bounding' positions of the layers i.e.: '0, 1.2, 3.7, 4.2' will mean 3 layers between those positions.

  • direction_maxMaximum coordinate along 'direction' that bounds the layers

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Maximum coordinate along 'direction' that bounds the layers

  • direction_minMinimum coordinate along 'direction' that bounds the layers

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Minimum coordinate along 'direction' that bounds the layers

  • fix_statesTrueWhether layer's frictional states are fixed after the number of nonlinear iterations set by 'iteration_number_state'. Setting this flag to false makes numerical results more accurate when behavior is on the limit between sticking and slipping. This extra level of accuracy comes at the expense of worse numerical convergence and an increased likelihood of time step cuts.

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Whether layer's frictional states are fixed after the number of nonlinear iterations set by 'iteration_number_state'. Setting this flag to false makes numerical results more accurate when behavior is on the limit between sticking and slipping. This extra level of accuracy comes at the expense of worse numerical convergence and an increased likelihood of time step cuts.

  • is_secondary_sideFalseWhether this user object acts on a secondary surface. Otherwise, another user object providing contact pressure is required.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether this user object acts on a secondary surface. Otherwise, another user object providing contact pressure is required.

  • iteration_number_state3The Newton or nonlinear iteration number at which the frictional states of the layers will be fixed for the entire time step.

    Default:3

    C++ Type:unsigned int

    Controllable:No

    Description:The Newton or nonlinear iteration number at which the frictional states of the layers will be fixed for the entire time step.

  • penalty_factor1e+13Penalty factor used to enforce the sticking conditions on out of plane strain increments for fuel and cladding. The default value has demonstrated to work well in typical simulation scenarios.

    Default:1e+13

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Penalty factor used to enforce the sticking conditions on out of plane strain increments for fuel and cladding. The default value has demonstrated to work well in typical simulation scenarios.

  • scalar_num_variable_claddingCladding scalar variables for axisymmetric 1D problem (num_name)

    C++ Type:unsigned int

    Controllable:No

    Description:Cladding scalar variables for axisymmetric 1D problem (num_name)

  • scalar_num_variable_fuelFuel scalar variables for axisymmetric 1D problem (num_name)

    C++ Type:unsigned int

    Controllable:No

    Description:Fuel scalar variables for axisymmetric 1D problem (num_name)

  • scalar_var_name_base_claddingCladding scalar variables for axisymmetric 1D problem (base_name)

    C++ Type:std::string

    Controllable:No

    Description:Cladding scalar variables for axisymmetric 1D problem (base_name)

  • scalar_var_name_base_fuelFuel scalar variables for axisymmetric 1D problem (base_name)

    C++ Type:std::string

    Controllable:No

    Description:Fuel scalar variables for axisymmetric 1D problem (base_name)

  • secondary_side_frictional_user_objectSecondary side frictional user object used to provide contact pressure.

    C++ Type:UserObjectName

    Controllable:No

    Description:Secondary side frictional user object used to provide contact pressure.

  • tangential_pressureThe auxiliary variable that holds the tangential contact pressure generated by the layered 1D friction user objects.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The auxiliary variable that holds the tangential contact pressure generated by the layered 1D friction user objects.

  • unique_node_executeFalseWhen false (default), block restricted objects will have the execute method called multiple times on a single node if the node lies on a interface between two subdomains.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:When false (default), block restricted objects will have the execute method called multiple times on a single node if the node lies on a interface between two subdomains.

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).

  • execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.

    Default:TIMESTEP_END

    C++ Type:ExecFlagEnum

    Options:XFEM_MARK, NONE, INITIAL, LINEAR, NONLINEAR_CONVERGENCE, 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. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.

  • 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

Execution Scheduling 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.

  • 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