FindValueOnLine

The FindValueOnLine Postprocessor is for sampling a line through a mesh or on a boundary looking for the point at which a specific value occurs. The values of the line must behave monotonically or an indeterminate solution may be found.

Find a specific target value along a sampling line. The variable values along the line should change monotonically. The target value is searched using a bisection algorithm.

Input Parameters

depth36Maximum number of bisections to perform.
Default:36
C++ Type:unsigned int
Options:
Description:Maximum number of bisections to perform.
end_pointEnd point of the sampling line.
C++ Type:libMesh::Point
Options:
Description:End point of the sampling line.
execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.
Default:TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE INITIAL LINEAR NONLINEAR TIMESTEP_END TIMESTEP_BEGIN FINAL CUSTOM TRANSFER
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, FINAL, CUSTOM.
start_pointStart point of the sampling line.
C++ Type:libMesh::Point
Options:
Description:Start point of the sampling line.
targetTarget value to locate.
C++ Type:double
Options:
Description:Target value to locate.
tol1e-10Stop search if a value is found that is equal to the target with this tolerance applied.
Default:1e-10
C++ Type:double
Options:
Description:Stop search if a value is found that is equal to the target with this tolerance applied.
vVariable to inspect
C++ Type:std::vector
Options:
Description:Variable to inspect

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
Options:
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
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.
force_preauxFalseForces the GeneralUserObject to be executed in PREAUX
Default:False
C++ Type:bool
Options:
Description:Forces the GeneralUserObject to be executed in PREAUX
outputsVector of output names were you would like to restrict the output of variables(s) associated with this object
C++ Type:std::vector
Options:
Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object
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

Input Files

modules/combined/examples/phase_field-mechanics/kks_mechanics_KHS.i
test/tests/postprocessors/find_value_on_line/findvalueonline.i

modules/combined/examples/phase_field-mechanics/kks_mechanics_KHS.i

# KKS phase-field model coupled with elasticity using Khachaturyan's scheme as
# described in L.K. Aagesen et al., Computational Materials Science, 140, 10-21 (2017)
# Original run #170403a

[Mesh]
  type = GeneratedMesh
  dim = 3
  nx = 640
  ny = 1
  nz = 1
  xmin = -10
  xmax = 10
  ymin = 0
  ymax = 0.03125
  zmin = 0
  zmax = 0.03125
  elem_type = HEX8
[]


[Variables]
  # order parameter
  [./eta]
    order = FIRST
    family = LAGRANGE
  [../]

  # solute concentration
  [./c]
    order = FIRST
    family = LAGRANGE
  [../]

  # chemical potential
  [./w]
    order = FIRST
    family = LAGRANGE
  [../]

  # solute phase concentration (matrix)
  [./cm]
    order = FIRST
    family = LAGRANGE
  [../]
  # solute phase concentration (precipitate)
  [./cp]
    order = FIRST
    family = LAGRANGE
  [../]
  [./disp_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./disp_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./disp_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[ICs]
  [./eta_ic]
    variable = eta
    type = FunctionIC
    function = ic_func_eta
    block = 0
  [../]
  [./c_ic]
    variable = c
    type = FunctionIC
    function = ic_func_c
    block = 0
  [../]
  [./w_ic]
    variable = w
    type = ConstantIC
    value = 0.00991
    block = 0
  [../]
  [./cm_ic]
    variable = cm
    type = ConstantIC
    value = 0.131
    block = 0
  [../]
  [./cp_ic]
    variable = cp
    type = ConstantIC
    value = 0.236
    block = 0
  [../]
[]

[Functions]
  [./ic_func_eta]
    type = ParsedFunction
    value = '0.5*(1.0+tanh((x)/delta_eta/sqrt(2.0)))'
    vars = 'delta_eta'
    vals = '0.8034'
  [../]
  [./ic_func_c]
    type = ParsedFunction
    value = '0.2389*(0.5*(1.0+tanh(x/delta/sqrt(2.0))))^3*(6*(0.5*(1.0+tanh(x/delta/sqrt(2.0))))^2-15*(0.5*(1.0+tanh(x/delta/sqrt(2.0))))+10)+0.1339*(1-(0.5*(1.0+tanh(x/delta/sqrt(2.0))))^3*(6*(0.5*(1.0+tanh(x/delta/sqrt(2.0))))^2-15*(0.5*(1.0+tanh(x/delta/sqrt(2.0))))+10))'
    vars = 'delta'
    vals = '0.8034'
  [../]
  [./psi_eq_int]
    type = ParsedFunction
    value = 'volume*psi_alpha'
    vars = 'volume psi_alpha'
    vals = 'volume psi_alpha'
  [../]
  [./gamma]
    type = ParsedFunction
    value = '(psi_int - psi_eq_int) / dy / dz'
    vars = 'psi_int psi_eq_int dy       dz'
    vals = 'psi_int psi_eq_int 0.03125  0.03125'
  [../]
[]

[AuxVariables]
  [./sigma11]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./sigma22]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./sigma33]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e11]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e12]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e22]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e33]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_el11]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_el12]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_el22]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./f_el]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./eigen_strain00]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./Fglobal]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./psi]
    order = CONSTANT
    family = MONOMIAL
  [../]
[]

[AuxKernels]
  [./matl_sigma11]
    type = RankTwoAux
    rank_two_tensor = stress
    index_i = 0
    index_j = 0
    variable = sigma11
  [../]
  [./matl_sigma22]
    type = RankTwoAux
    rank_two_tensor = stress
    index_i = 1
    index_j = 1
    variable = sigma22
  [../]
  [./matl_sigma33]
    type = RankTwoAux
    rank_two_tensor = stress
    index_i = 2
    index_j = 2
    variable = sigma33
  [../]
  [./matl_e11]
    type = RankTwoAux
    rank_two_tensor = total_strain
    index_i = 0
    index_j = 0
    variable = e11
  [../]
  [./f_el]
    type = MaterialRealAux
    variable = f_el
    property = f_el_mat
    execute_on = timestep_end
  [../]
  [./GlobalFreeEnergy]
    variable = Fglobal
    type = KKSGlobalFreeEnergy
    fa_name = fm
    fb_name = fp
    w = 0.0264
    kappa_names = kappa
    interfacial_vars = eta
  [../]
  [./psi_potential]
    variable = psi
    type = ParsedAux
    args = 'Fglobal w c f_el sigma11 e11'
    function = 'Fglobal - w*c + f_el - sigma11*e11'
  [../]
[]


[BCs]
  [./left_x]
    type = DirichletBC
    variable = disp_x
    boundary = left
    value = 0
  [../]
  [./right_x]
    type = DirichletBC
    variable = disp_x
    boundary = right
    value = 0
  [../]
  [./front_y]
    type = DirichletBC
    variable = disp_y
    boundary = front
    value = 0
  [../]
  [./back_y]
    type = DirichletBC
    variable = disp_y
    boundary = back
    value = 0
  [../]
  [./top_z]
    type = DirichletBC
    variable = disp_z
    boundary = top
    value = 0
  [../]
  [./bottom_z]
    type = DirichletBC
    variable = disp_z
    boundary = bottom
    value = 0
  [../]
[]

[Materials]
  # Chemical free energy of the matrix
  [./fm]
    type = DerivativeParsedMaterial
    f_name = fm
    args = 'cm'
    function = '6.55*(cm-0.13)^2'
  [../]

  # Chemical Free energy of the precipitate phase
  [./fp]
    type = DerivativeParsedMaterial
    f_name = fp
    args = 'cp'
    function = '6.55*(cp-0.235)^2'
  [../]

# Elastic energy of the precipitate
  [./elastic_free_energy_p]
    type = ElasticEnergyMaterial
    f_name = f_el_mat
    args = 'eta'
    outputs = exodus
  [../]


  # h(eta)
  [./h_eta]
    type = SwitchingFunctionMaterial
    h_order = HIGH
    eta = eta
  [../]

  # 1- h(eta), putting in function explicitly
  [./one_minus_h_eta_explicit]
    type = DerivativeParsedMaterial
    f_name = one_minus_h_explicit
    args = eta
    function = 1-eta^3*(6*eta^2-15*eta+10)
    outputs = exodus
  [../]

  # g(eta)
  [./g_eta]
    type = BarrierFunctionMaterial
    g_order = SIMPLE
    eta = eta
  [../]

  # constant properties
  [./constants]
    type = GenericConstantMaterial
    prop_names  = 'M   L   kappa      misfit'
    prop_values = '0.7 0.7 0.01704    0.00377'
  [../]

  #Mechanical properties
  [./Stiffness_matrix]
    type = ComputeElasticityTensor
    base_name = C_matrix
    C_ijkl = '103.3 74.25 74.25 103.3 74.25 103.3 46.75 46.75 46.75'
    fill_method = symmetric9
  [../]
  [./Stiffness_ppt]
    type = ComputeElasticityTensor
    C_ijkl = '100.7 71.45 71.45 100.7 71.45 100.7 50.10 50.10 50.10'
    base_name = C_ppt
    fill_method = symmetric9
  [../]
  [./C]
    type = CompositeElasticityTensor
    args = eta
    tensors = 'C_matrix               C_ppt'
    weights = 'one_minus_h_explicit   h'
  [../]
  [./stress]
    type = ComputeLinearElasticStress
  [../]
  [./strain]
    type = ComputeSmallStrain
    displacements = 'disp_x disp_y disp_z'
    eigenstrain_names = 'eigenstrain_ppt'
  [../]
  [./eigen_strain]
    type = ComputeVariableEigenstrain
    eigen_base = '0.00377 0.00377 0.00377 0 0 0'
    prefactor = h
    args = eta
    eigenstrain_name = 'eigenstrain_ppt'
  [../]
[]

[Kernels]
  [./TensorMechanics]
    displacements = 'disp_x disp_y disp_z'
  [../]

  # enforce c = (1-h(eta))*cm + h(eta)*cp
  [./PhaseConc]
    type = KKSPhaseConcentration
    ca       = cm
    variable = cp
    c        = c
    eta      = eta
  [../]

  # enforce pointwise equality of chemical potentials
  [./ChemPotVacancies]
    type = KKSPhaseChemicalPotential
    variable = cm
    cb       = cp
    fa_name  = fm
    fb_name  = fp
  [../]

  #
  # Cahn-Hilliard Equation
  #
  [./CHBulk]
    type = KKSSplitCHCRes
    variable = c
    ca       = cm
    fa_name  = fm
    w        = w
  [../]

  [./dcdt]
    type = CoupledTimeDerivative
    variable = w
    v = c
  [../]
  [./ckernel]
    type = SplitCHWRes
    mob_name = M
    variable = w
  [../]

  #
  # Allen-Cahn Equation
  #
  [./ACBulkF]
    type = KKSACBulkF
    variable = eta
    fa_name  = fm
    fb_name  = fp
    w        = 0.0264
    args = 'cp cm'
  [../]
  [./ACBulkC]
    type = KKSACBulkC
    variable = eta
    ca       = cm
    cb       = cp
    fa_name  = fm
  [../]
  [./ACBulk_el] #This adds df_el/deta for strain interpolation
    type = AllenCahn
    variable = eta
    f_name = f_el_mat
  [../]
  [./ACInterface]
    type = ACInterface
    variable = eta
    kappa_name = kappa
  [../]
  [./detadt]
    type = TimeDerivative
    variable = eta
  [../]
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'
  petsc_options_iname = '-pc_type -sub_pc_type   -sub_pc_factor_shift_type'
  petsc_options_value = 'asm       ilu            nonzero'

  l_max_its = 30
  nl_max_its = 10
  l_tol = 1.0e-4
  nl_rel_tol = 1.0e-8
  nl_abs_tol = 1.0e-11
  num_steps = 200

  [./TimeStepper]
    type = SolutionTimeAdaptiveDT
    dt = 0.5
  [../]
[]

[Postprocessors]
  [./f_el_int]
    type = ElementIntegralMaterialProperty
    mat_prop = f_el_mat
  [../]
  [./c_alpha]
    type =  SideAverageValue
    boundary = left
    variable = c
  [../]
  [./c_beta]
    type =  SideAverageValue
    boundary = right
    variable = c
  [../]
  [./e11_alpha]
    type =  SideAverageValue
    boundary = left
    variable = e11
  [../]
  [./e11_beta]
    type =  SideAverageValue
    boundary = right
    variable = e11
  [../]
  [./s11_alpha]
    type =  SideAverageValue
    boundary = left
    variable = sigma11
  [../]
  [./s22_alpha]
    type =  SideAverageValue
    boundary = left
    variable = sigma22
  [../]
  [./s33_alpha]
    type =  SideAverageValue
    boundary = left
    variable = sigma33
  [../]
  [./s11_beta]
    type =  SideAverageValue
    boundary = right
    variable = sigma11
  [../]
  [./s22_beta]
    type =  SideAverageValue
    boundary = right
    variable = sigma22
  [../]
  [./s33_beta]
    type =  SideAverageValue
    boundary = right
    variable = sigma33
  [../]
  [./f_el_alpha]
    type =  SideAverageValue
    boundary = left
    variable = f_el
  [../]
  [./f_el_beta]
    type =  SideAverageValue
    boundary = right
    variable = f_el
  [../]
  [./f_c_alpha]
    type =  SideAverageValue
    boundary = left
    variable = Fglobal
  [../]
  [./f_c_beta]
    type =  SideAverageValue
    boundary = right
    variable = Fglobal
  [../]
  [./chem_pot_alpha]
    type =  SideAverageValue
    boundary = left
    variable = w
  [../]
  [./chem_pot_beta]
    type =  SideAverageValue
    boundary = right
    variable = w
  [../]
  [./psi_alpha]
    type =  SideAverageValue
    boundary = left
    variable = psi
  [../]
  [./psi_beta]
    type =  SideAverageValue
    boundary = right
    variable = psi
  [../]
  [./total_energy]
    type = ElementIntegralVariablePostprocessor
    variable = Fglobal
  [../]
  # Get simulation cell size from postprocessor
  [./volume]
    type = ElementIntegralMaterialProperty
    mat_prop = 1
  [../]
  [./psi_eq_int]
    type = FunctionValuePostprocessor
    function = psi_eq_int
  [../]
  [./psi_int]
    type = ElementIntegralVariablePostprocessor
    variable = psi
  [../]
  [./gamma]
    type = FunctionValuePostprocessor
    function = gamma
  [../]
  [./int_position]
    type = FindValueOnLine
    start_point = '-10 0 0'
    end_point = '10 0 0'
    v = eta
    target = 0.5
  [../]
[]

#
# Precondition using handcoded off-diagonal terms
#
[Preconditioning]
  [./full]
    type = SMP
    full = true
  [../]
[]


[Outputs]
  [./exodus]
    type = Exodus
    interval = 20
  [../]
  checkpoint = true
  [./csv]
    type = CSV
    execute_on = 'final'
  [../]
[]

test/tests/postprocessors/find_value_on_line/findvalueonline.i

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 20
  xmin = 0
  xmax = 10
[]

[Variables]
  [./phi]
    [./InitialCondition]
      type = FunctionIC
      function = if(x<1,1-x,0)
    [../]
  [../]
[]

[Kernels]
  [./diff]
    type = Diffusion
    variable = phi
  [../]
  [./dt]
    type = TimeDerivative
    variable = phi
  [../]
[]

[BCs]
  [./influx]
    type = NeumannBC
    boundary = left
    variable = phi
    value = 1
  [../]
  [./fix]
    type = DirichletBC
    boundary = right
    variable = phi
    value = 0
  [../]
[]

[Postprocessors]
  [./pos]
    type = FindValueOnLine
    target = 0.5
    v = phi
    start_point = '0 0 0'
    end_point = '10 0 0'
    execute_on = 'initial timestep_end'
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 5
  dt = 2.5
[]

[Outputs]
  csv = true
[]

References

Input Parameters
Input Files
References

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