StepPeriod

The StepPeriod class derives from ConditionalEnableControl.

StepPeriod objects are designed to control the active state of a MOOSE object, based on whether the time value is in some range.

For example, consider a simulation that contains two Kernels "diff0" and "diff1". Initially, "diff0" is active and after time 0.49 "diff1" becomes active and "diff0" is disabled. The following code snippet demonstrates how this switching of kernels is achieved with the TimePeriod object.

This object, unlike TimePeriod, is controlled by the loading 'step' concept. The user defines time periods, i.e. steps, over which the boundary conditions and contraints are not disabled/enabled. A step number is thus a required input to this control object. At the beginning of this step number, boundary conditions and constraints are enabled or disabled, as directed by StepUserObject. Only one step is allowed per StepPeriod object.

[step1]
  type = StepPeriod
  enable_objects = 'BCs::y_step1'
  disable_objects = 'BCs::y_pull_function_step2'
  step_user_object = step_uo
  step_number = 0
[]

Input Parameters

step_numberStep number on which this control object applies.
C++ Type:unsigned int
Controllable:No
Description:Step number on which this control object applies.

Required Parameters

depends_onThe Controls that this control relies upon (i.e. must execute before this one)
C++ Type:std::vector<std::string>
Controllable:No
Description:The Controls that this control relies upon (i.e. must execute before this one)
disable_objectsA list of object tags to disable.
C++ Type:std::vector<std::string>
Controllable:No
Description:A list of object tags to disable.
enable_objectsA list of object tags to enable.
C++ Type:std::vector<std::string>
Controllable:No
Description:A list of object tags to enable.
execute_onINITIAL TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS.
Default:INITIAL TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS, PRE_MULTIAPP_SETUP
Controllable:No
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, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS.
reverse_on_falseTrueWhen true, the disable/enable lists are set to opposite values when the specified condition is false.
Default:True
C++ Type:bool
Controllable:No
Description:When true, the disable/enable lists are set to opposite values when the specified condition is false.
set_sync_timesTrueSet the start and end time as execute sync times.
Default:True
C++ Type:bool
Controllable:No
Description:Set the start and end time as execute sync times.
step_user_objectThe StepUserObject that provides times from simulation loading steps.
C++ Type:UserObjectName
Controllable:No
Description:The StepUserObject that provides times from simulation loading steps.

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:No
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

Advanced Parameters

(moose/modules/tensor_mechanics/test/tests/umat/steps/elastic_temperature_steps_uo.i)

# Testing the UMAT Interface - linear elastic model using the large strain formulation.

[GlobalParams]
  displacements = 'disp_x disp_y disp_z'
[]

[Mesh]
  [gen]
    type = GeneratedMeshGenerator
    dim = 3
    xmin = -0.5
    xmax = 0.5
    ymin = -0.5
    ymax = 0.5
    zmin = -0.5
    zmax = 0.5
  []
[]

[Functions]
  [top_pull_step2]
    type = ParsedFunction
    expression = (t-5.0)/20
  []
  # Forced evolution of temperature
  [temperature_load]
    type = ParsedFunction
    expression = '273'
  []
[]

[AuxVariables]
  [temperature]
  []
[]

[AuxKernels]
  [temperature_function]
    type = FunctionAux
    variable = temperature
    function = temperature_load
  []
[]

[Modules/TensorMechanics/Master]
  [all]
    add_variables = true
    strain = FINITE
    generate_output = 'stress_yy'
  []
[]

[BCs]
  [y_step1]
    type = DirichletBC
    variable = disp_y
    boundary = top
    value = 0.0
  []
  [y_pull_function_step2]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = top
    function = top_pull_step2
  []
  [x_bot]
    type = DirichletBC
    variable = disp_x
    boundary = left
    value = 0.0
  []
  [y_bot]
    type = DirichletBC
    variable = disp_y
    boundary = bottom
    value = 0.0
  []
  [z_bot]
    type = DirichletBC
    variable = disp_z
    boundary = front
    value = 0.0
  []
[]

[Controls]
  [step1]
    type = StepPeriod
    enable_objects = 'BCs::y_step1'
    disable_objects = 'BCs::y_pull_function_step2'
    step_user_object = step_uo
    step_number = 0
  []
  [step2]
    type = StepPeriod
    enable_objects = 'BCs::y_pull_function_step2'
    disable_objects = 'BCs::y_step1'
    step_user_object = step_uo
    step_number = 1
  []
[]

[UserObjects]
  [step_uo]
   type = StepUserObject
   step_start_times = '0 5'
  []
[]

[Materials]
  [umat]
    type = AbaqusUMATStress
    constant_properties = '1000 0.3'
    plugin = '../../../plugins/elastic_temperature'
    num_state_vars = 0
    temperature = temperature
    use_one_based_indexing = true
  []
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'

  petsc_options = '-snes_ksp_ew'
  petsc_options_iname = '-ksp_gmres_restart'
  petsc_options_value = '101'

  line_search = 'none'

  l_max_its = 100
  nl_max_its = 100
  nl_rel_tol = 1e-12
  nl_abs_tol = 1e-10
  l_tol = 1e-9
  start_time = 0.0
  num_steps = 10
  dt = 1.0
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Outputs]
  exodus = true
[]