BVRTL2020ModelUpdate

construction:Undocumented Class

The BVRTL2020ModelUpdate has not been documented. The content listed below should be used as a starting point for documenting the class, which includes the typical automatic documentation associated with a MooseObject; however, what is contained is ultimately determined by what is necessary to make the documentation clear for users.

Material for computing a RTL2020 creep update. See Azabou et al. (2021), Rock salt behavior: From laboratory experiments to pertinent long-term predictions.

Overview

Example Input File Syntax

Input Parameters

AThe A parameter.
C++ Type:double
Unit:(no unit assumed)
Range:A >= 0.0
Controllable:No
Description:The A parameter.
A1The A1 parameter.
C++ Type:double
Unit:(no unit assumed)
Range:A1 > 0.0
Controllable:No
Description:The A1 parameter.
A2The A2 parameter.
C++ Type:double
Unit:(no unit assumed)
Range:A2 > 0.0
Controllable:No
Description:The A2 parameter.
BThe B parameter.
C++ Type:double
Unit:(no unit assumed)
Range:B >= 0.0
Controllable:No
Description:The B parameter.
alphaThe alpha parameter.
C++ Type:double
Unit:(no unit assumed)
Range:0.0 < alpha & alpha < 1.0
Controllable:No
Description:The alpha parameter.
mThe m parameter.
C++ Type:double
Unit:(no unit assumed)
Range:m > 1.0
Controllable:No
Description:The m parameter.
nThe n parameter.
C++ Type:double
Unit:(no unit assumed)
Range:n > 1.0
Controllable:No
Description:The n parameter.
n1The n1 parameter.
C++ Type:double
Unit:(no unit assumed)
Range:n1 > 0.0
Controllable:No
Description:The n1 parameter.
n2The n2 parameter.
C++ Type:double
Unit:(no unit assumed)
Range:n2 > 0.0
Controllable:No
Description:The n2 parameter.

Required Parameters

Ar0The activation temperature in Kelvin.
Default:0
C++ Type:double
Unit:(no unit assumed)
Range:Ar >= 0.0
Controllable:No
Description:The activation temperature in Kelvin.
Mz1volumetric creep parameter Mz
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:volumetric creep parameter Mz
Nz1volumetric creep parameter Nz
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:volumetric creep parameter Nz
Tr289The reference temperature in Kelvin.
Default:289
C++ Type:double
Unit:(no unit assumed)
Range:Tr > 0.0
Controllable:No
Description:The reference temperature in Kelvin.
abs_tolerance1e-10The absolute tolerance for the iterative update.
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Range:abs_tolerance > 0.0
Controllable:No
Description:The absolute tolerance for the iterative update.
base_nameOptional parameter that defines a prefix for all material properties related to this stress update model. This allows for multiple models of the same type to be used without naming conflicts.
C++ Type:std::string
Controllable:No
Description:Optional parameter that defines a prefix for all material properties related to this stress update model. This allows for multiple models of the same type to be used without naming conflicts.
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
constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
Default:NONE
C++ Type:MooseEnum
Options:NONE, ELEMENT, SUBDOMAIN
Controllable:No
Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
declare_suffixAn optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Unit:(no unit assumed)
Controllable:No
Description:An optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
max_iterations200The maximum number of iterations for the iterative update
Default:200
C++ Type:unsigned int
Range:max_iterations >= 1
Controllable:No
Description:The maximum number of iterations for the iterative update
mz1volumetric creep parameter mz
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:volumetric creep parameter mz
nz1volumetric creep parameter nz
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:volumetric creep parameter nz
rel_tolerance1e-10The relative tolerance for the iterative update.
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Range:rel_tolerance > 0.0
Controllable:No
Description:The relative tolerance for the iterative update.
temperatureThe temperature variable in Kelvin.
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:The temperature variable in Kelvin.
volumetricFalseWhether to perform a volumetric correction.
Default:False
C++ Type:bool
Controllable:No
Description:Whether to perform a volumetric correction.
z0volumetric creep parameter z
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:volumetric creep parameter z

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
search_methodnearest_node_connected_sidesChoice of search algorithm. All options begin by finding the nearest node in the primary boundary to a query point in the secondary boundary. In the default nearest_node_connected_sides algorithm, primary boundary elements are searched iff that nearest node is one of their nodes. This is fast to determine via a pregenerated node-to-elem map and is robust on conforming meshes. In the optional all_proximate_sides algorithm, primary boundary elements are searched iff they touch that nearest node, even if they are not topologically connected to it. This is more CPU-intensive but is necessary for robustness on any boundary surfaces which has disconnections (such as Flex IGA meshes) or non-conformity (such as hanging nodes in adaptively h-refined meshes).
Default:nearest_node_connected_sides
C++ Type:MooseEnum
Options:nearest_node_connected_sides, all_proximate_sides
Controllable:No
Description:Choice of search algorithm. All options begin by finding the nearest node in the primary boundary to a query point in the secondary boundary. In the default nearest_node_connected_sides algorithm, primary boundary elements are searched iff that nearest node is one of their nodes. This is fast to determine via a pregenerated node-to-elem map and is robust on conforming meshes. In the optional all_proximate_sides algorithm, primary boundary elements are searched iff they touch that nearest node, even if they are not topologically connected to it. This is more CPU-intensive but is necessary for robustness on any boundary surfaces which has disconnections (such as Flex IGA meshes) or non-conformity (such as hanging nodes in adaptively h-refined meshes).
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

output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)
C++ Type:std::vector<std::string>
Controllable:No
Description:List of material properties, from this material, to output (outputs must also be defined to an output type)
outputsnone Vector of output names where you would like to restrict the output of variables(s) associated with this object
Default:none
C++ Type:std::vector<OutputName>
Controllable:No
Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

Outputs Parameters

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
Unit:(no unit assumed)
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.
use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.
Default:False
C++ Type:bool
Controllable:No
Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Material Property Retrieval Parameters

Input Files

(examples/viscoelasticity/RTL2020/BVRTL2020ModelUpdate.i)
(examples/viscoelasticity/lemaitre/lemaitre.i)
(examples/viscoelasticity/parametric/parametric.i)
(examples/viscoelasticity/RTL2020/BVRTL2020salt5triaxialtest3.i)
(examples/viscoelasticity/RTL2020/BVRTL2020salt5triaxialtest1.i)
(examples/viscoelasticity/RTL2020/BVRTL2020salt5creeptest.i)
(examples/viscoelasticity/RTL2020/BVRTL2020salt5triaxialtest2.i)
(examples/viscoelasticity/munson-dawson/munson_dawson.i)

(examples/viscoelasticity/RTL2020/BVRTL2020ModelUpdate.i)

# RTL2020 creep model
# See Figures 3,4,5 and 6 of Azabou et al. (2021)
# Parameters
# Units: stress in MPa, time in days, strain in m / m
E = 28567
nu = 0.30
alpha = 0.2601 
# alpha = 0.4483 # * 1.72345 to account for T
A1 = 0.0181
n1 = 1.162
A2 = 0.3986
n2 = 9.6768
A = 0.01
# A = 0.0172 # * 1.72345 to account for T
n = 13.5
B = 0.0
m = 2.0
Tr = 289
Ar = 1725
#Psalt1 = 8
#Psalt2 = 8
Psalt3 = 10.0
#Psalt4 = 15
#Qsalt1 = 12.0
#Qsalt2 = 12.0
Qsalt3 = 12.0
#Qsalt4 = 19.4
# Nz = 0.0241
# nz = 1.2644
# Mz = 0.024
# mz = 1.028
# z = 0.4523

[Mesh]
  type = GeneratedMesh
  dim = 3
  # nx = 5
  # ny = 10
  # nz = 5
  nx = 1
  ny = 1
  nz = 1
  xmin = 0
  xmax = 65e-03
  ymin = 0
  ymax = 130e-03
  zmin = 0
  zmax = 65e-03
[]
  
[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]
  
[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]
  
[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 313.15 #note: temperature for salt2 is 313.15K
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
[]
  
[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 313
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
  [strain_zz_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_zz_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
[]
  
[Functions]
  [salt1loading]
    type = ParsedFunction 
    expression = 'if(t<=14,12,if(t<=28,16,20))' 
  []
  [salt2loading]
    type = ParsedFunction 
    expression = 'if(t<=15,12,if(t<=29,16,if(t<=32,20,20.2)))' 
  []
  [salt3loading]
    type = ParsedFunction 
    expression = 'if(t<=15,15,if(t<=28,20,25))' 
  []
  [salt4loading]
    type = ParsedFunction 
    expression = 'if(t<=12,19.4,if(t<=29,23.4,27))' 
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      value = ${Psalt3}
    []
    [pressure_front]
      boundary = 'front'
      displacement_vars = 'disp_x disp_y disp_z'
      value = ${Psalt3}
    []
    [pressure_top]
      boundary = 'top'
      displacement_vars = 'disp_x disp_y disp_z'
      function = salt3loading 
    []
  []
[]
  
[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${Psalt3} -${Qsalt3} -${Psalt3}'
    inelastic_models = 'viscoelastic'
  []
  #[viscoelastic]
  #  type = BVModifiedLemaitreModelUpdate 
  #  alpha = ${alpha}
  #  kr1 = ${kr1}
  #  beta1 = ${beta1} 
  #  kr2 = ${kr2}
  #  beta2 = ${beta2}
  #[]
  #[viscoelastic]
  #  type = BVBlancoMartinModelUpdate 
  #  alpha = ${alpha}
  #  kr1 = ${kr1}
  #  beta1 = ${beta1} 
  #  kr2 = ${kr2}
  #  beta2 = ${beta2}
  #  A1 = ${A1}
  #  n1 = ${n1}
  #  A = ${A}
  #  n = ${n}
  #  B = 0.0
  #  m = ${n}
  #[]
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = false
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    # Nz = ${Nz}
    # nz = ${nz}
    # Mz = ${Mz}
    # mz = ${mz}
    # z = ${z}
  []
[]

[Postprocessors]
   [eqv_strain_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
  [strain_zz]
    type = ElementAverageValue
    variable = strain_yy
    outputs = csv
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_yy
    outputs = csv
  []
  [q]
    type = ElementAverageValue
    variable = eqv_stress
    outputs = csv
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it
                           -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
  [superlu]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason -ksp_gmres_modifiedgramschmidt -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-snes_type
                           -snes_atol -snes_rtol -snes_max_it
                           -pc_type -pc_factor_mat_solver_package
                           -snes_linesearch_type'
    petsc_options_value = 'newtonls
                           1e-10 1e-12 50
                           lu superlu_dist
                           l2'
  []
  [asm]
    type = SMP
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-ksp_type
                           -pc_type
                           -sub_pc_type
                           -snes_type -snes_atol -snes_rtol -snes_max_it -snes_linesearch_type
                           -ksp_gmres_restart'
    petsc_options_value = 'fgmres
                           asm
                           ilu
                           newtonls 1e-10 1e-10 120 basic
                           201'
  []
[]
  
[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  automatic_scaling = true
  start_time = 0.0
  end_time = 50 # 50 days
  dt = 0.02
  timestep_tolerance = 1.0e-10
[]
  
[Outputs]
  perf_graph = true
  exodus = true
  [csv]
  type = CSV
  execute_on = 'timestep_end'
  []
[]

(examples/viscoelasticity/lemaitre/lemaitre.i)

# Input file for purely Lemaitre creep model based on RTL2020 model (Azabou et al. (2021)). 
# Note: Parameter A is set to zero to ensure the Munson-Dawson component is zero.
# Also, volumetric part is set to false and parameter z is set to zero.  
# Parameters
# Units used for the simulation: stress in MPa, time in days, strain in m / m

E = 6000
nu = 0.000044
alpha = 0.1 
A2 = 1
n2 = 14.8
Ar = 1
Tr = 289
# parameters for Munson-Dawson part
A1 = 1
n1 = 1
A = 0.0   
n = 10
B = 0.0
m = 2.2195
P = 1
# parameters for volumetric part
z = 0.0
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
  type = GeneratedMesh
  dim = 3
  nx = 1
  ny = 1
  nz = 2
  xmin = 0
  xmax = 1
  ymin = 0
  ymax = 1
  zmin = 0
  zmax = 0.1
[]

[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]

[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]

[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 289
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
[]

[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 289
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [strain_yy_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'front back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      value = 0.0
    []
    [pressure_top]
      boundary = 'top'
      displacement_vars = 'disp_x disp_y disp_z'
      value = -2.0
    []
  []
[]

[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} ${P} 0.0'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = false
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason  -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
[]

[Postprocessors]
  [e]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [e_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
[]

[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  start_time = 0.0
  end_time = 1 
  dt = 0.0001
[]

[Outputs]
  perf_graph = true
  execute_on = 'TIMESTEP_END'
  print_linear_residuals = false
  exodus = true
  [csv]
    type = CSV
  []
[]

(examples/viscoelasticity/parametric/parametric.i)

E = 22126
nu = 0.2
alpha = 0.5812 
A1 = 0.1854
n1 = 2.1012
A2 = 3.7009
n2 = 6.7562
A = 155.6582
n = 11.989
B = 0.01918
m = 2.2195
Tr = 289
Ar = 1725
P = 8.7
P_TCT = 5
Q = 12.7
z = 0.4523
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
    [efm]
    type = FileMeshGenerator
    file = regular.msh
    []
[]
  
[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]
  
[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]
  
[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 313
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_R]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_zz]
    order = CONSTANT
    family = MONOMIAL
  []
[]
  
[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 313
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_R_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_R
    property = eqv_creep_strain_R
    execute_on = 'TIMESTEP_END'
  []
  [strain_zz_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_yy_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_zz_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = z
    index_j = z
    execute_on = 'TIMESTEP_END'
  []
[]
  
[Functions]
  [Q_loading]
    type = ParsedFunction 
    expression = 'if(t<=10,12.7,if(t<=40,15,if(t<=90,20,if(t<=140,22,24))))' 
  []
  [P_loading]
    type = ParsedFunction 
    expression = 'if(t<=10,8.7,if(t<=40,7.5,if(t<=90,5,if(t<=140,4,3))))' 
  []
  [strain_rate]
  type = ParsedFunction
  vars = 'e_dot L'
  vals = '1.0e-06 130e-03'
  expression = 'e_dot*L*t'
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'West'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'Bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'North'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'East'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P_TCT} #P_loading, use P_TCT for the triaxial compress. test
    []
    [pressure_front]
      boundary = 'South'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P_TCT} #P_loading
    []
  #  [pressure_top]
  #    boundary = 'Top'
  #    displacement_vars = 'disp_x disp_y disp_z'
  #    function = Q_loading
  #  []
  []
  [strain_rate]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 'Top'
    function = strain_rate
  []
[]
  
[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} -${Q} -${P}'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = false
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Postprocessors]
   [eqv_strain_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
  [eqv_strain_R]
    type = ElementAverageValue
    variable = eqv_creep_strain_R
    outputs = csv
  []
  [strain_zz]
    type = ElementAverageValue
    variable = strain_yy
    outputs = csv
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_zz
    outputs = csv
  []
  [q]
    type = ElementAverageValue
    variable = eqv_stress
    outputs = csv
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it
                           -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
  [superlu]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason -ksp_gmres_modifiedgramschmidt -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-snes_type
                           -snes_atol -snes_rtol -snes_max_it
                           -pc_type -pc_factor_mat_solver_package
                           -snes_linesearch_type'
    petsc_options_value = 'newtonls
                           1e-10 1e-12 50
                           lu superlu_dist
                           l2'
  []
  [asm]
    type = SMP
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-ksp_type
                           -pc_type
                           -sub_pc_type
                           -snes_type -snes_atol -snes_rtol -snes_max_it -snes_linesearch_type
                           -ksp_gmres_restart'
    petsc_options_value = 'fgmres
                           asm
                           ilu
                           newtonls 1e-10 1e-10 120 basic
                           201'
  []
[]
  
[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  automatic_scaling = true
  start_time = 0.0
  end_time = 200 
  dt = 0.02
  timestep_tolerance = 1.0e-10
[]
  
[Outputs]
  perf_graph = true
  exodus = true
  [csv]
  type = CSV
  execute_on = 'timestep_end'
  []
[]

(examples/viscoelasticity/RTL2020/BVRTL2020salt5triaxialtest3.i)

# Modified Lemaitre creep model
# See the first three figures of Fig.8 in Azabou et al. (2021)
# Parameters
# Units: stress in MPa, time in days, strain in m / m
E = 22126
nu = 0.2
alpha = 0.5812 
A1 = 0.1854
n1 = 2.1012
A2 = 3.7009
n2 = 6.7562
A = 155.6582
n = 11.989
B = 0.01918
m = 2.2195
Tr = 289
Ar = 1725
P = 5 
z = 0.4523
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
  type = GeneratedMesh
  dim = 3
  # nx = 5
  # ny = 10
  # nz = 5
  nx = 1
  ny = 1
  nz = 1
  xmin = 0
  xmax = 65e-03
  ymin = 0
  ymax = 130e-03
  zmin = 0
  zmax = 65e-03
[]
  
[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]
  
[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]
  
[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 303.15 
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_R]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [vol_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [vol_strain_neg]
    order = CONSTANT
    family = MONOMIAL
  []
[]
  
[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 303.15 
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_R_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_R
    property = eqv_creep_strain_R
    execute_on = 'TIMESTEP_END'
  []
  [strain_zz_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_zz_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [vol_strain_aux]
    type = BVVolStrainAux
    variable = vol_strain
    execute_on = 'TIMESTEP_END'
  []
  [vol_strain_neg]
    type = ParsedAux
    coupled_variables = vol_strain 
    expression =  '-vol_strain'  
    variable = vol_strain_neg
  []
[]
  
[Functions]
  [P_confining]
  type = ParsedFunction
  symbol_names = 'p_dot'
  symbol_values = '-1e6' # Pa/s
  expression = '-p_dot*t' # no need to converted time to per days. final pressure is in Pa
  []
  [Q_axial]
  type = ParsedFunction
  symbol_names = 'P_c'
  symbol_values = 'P_confining'
  expression = '51-(2*P_c)'
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      function = P_confining 
    []
    [pressure_front]
      boundary = 'front'
      displacement_vars = 'disp_x disp_y disp_z'
      function = P_confining
    []
    [pressure_top]
      boundary = 'top'
     displacement_vars = 'disp_x disp_y disp_z'
      function = Q_axial
    []
  []
 # [axial_stress]
 #   type = FunctionDirichletBC
 #   variable = disp_y
 #   boundary = 'top'
 #   function = Q_axial
 # []
[]
  
[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} -${P} -${P}'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = true
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Postprocessors]
   [eqv_strain_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
  [eqv_strain_R]
    type = ElementAverageValue
    variable = eqv_creep_strain_R
    outputs = csv
  []
  [strain_zz]
    type = ElementAverageValue
    variable = strain_yy
    outputs = csv
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_yy
    outputs = csv
  []
  [q]
    type = ElementAverageValue
    variable = eqv_stress
    outputs = csv
  []
  [vol_strain]
    type = ElementAverageValue
    variable = vol_strain_neg   #used parsedaux kernel to turn the vol strain into negative 
    outputs = csv
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it
                           -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
  [superlu]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason -ksp_gmres_modifiedgramschmidt -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-snes_type
                           -snes_atol -snes_rtol -snes_max_it
                           -pc_type -pc_factor_mat_solver_package
                           -snes_linesearch_type'
    petsc_options_value = 'newtonls
                           1e-10 1e-12 50
                           lu superlu_dist
                           l2'
  []
  [asm]
    type = SMP
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-ksp_type
                           -pc_type
                           -sub_pc_type
                           -snes_type -snes_atol -snes_rtol -snes_max_it -snes_linesearch_type
                           -ksp_gmres_restart'
    petsc_options_value = 'fgmres
                           asm
                           ilu
                           newtonls 1e-10 1e-10 120 basic
                           201'
  []
[]
  
[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  automatic_scaling = true
  start_time = 0.0
  end_time =  0.8873456790123455  #200 
  num_steps = 800
  #dt = 0.001
  timestep_tolerance = 1.0e-10
[]
  
[Outputs]
  perf_graph = true
  exodus = true
  [csv]
  type = CSV
  execute_on = 'timestep_end'
  []
[]

(examples/viscoelasticity/RTL2020/BVRTL2020salt5triaxialtest1.i)

# Modified Lemaitre creep model
# See the first three figures of Fig.8 in Azabou et al. (2021)
# Parameters
# Units: stress in MPa, time in days, strain in m / m
E = 22126
nu = 0.2
alpha = 0.5812 
A1 = 0.1854
n1 = 2.1012
A2 = 3.7009
n2 = 6.7562
A = 155.6582
n = 11.989
B = 0.01918
m = 2.2195
Tr = 289
Ar = 1725
P = 5 
z = 0.4523
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
  type = GeneratedMesh
  dim = 3
  # nx = 5
  # ny = 10
  # nz = 5
  nx = 1
  ny = 1
  nz = 1
  xmin = 0
  xmax = 65e-03
  ymin = 0
  ymax = 130e-03
  zmin = 0
  zmax = 65e-03
[]
  
[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]
  
[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]
  
[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 292.15
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_R]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [vol_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [vol_strain_neg]
    order = CONSTANT
    family = MONOMIAL
  []
[]
  
[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 292.15
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_R_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_R
    property = eqv_creep_strain_R
    execute_on = 'TIMESTEP_END'
  []
  [strain_zz_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_zz_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [vol_strain_aux]
    type = BVVolStrainAux
    variable = vol_strain
    execute_on = 'TIMESTEP_END'
  []
  [vol_strain_neg]
    type = ParsedAux
    coupled_variables = vol_strain 
    expression =  '-vol_strain'  
    variable = vol_strain_neg
  []
[]
  
[Functions]
  [strain_rate]
  type = ParsedFunction
  symbol_names = 'e_dot L'
  symbol_values = '1.0e-06 130e-03'
  expression = '-e_dot*L*t*86400' #converted to per days
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P} 
    []
    [pressure_front]
      boundary = 'front'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P} 
    []
  []
  [strain_rate]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 'top'
    function = strain_rate
  []
[]
  
[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} -${P} -${P}'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = true
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Postprocessors]
   [eqv_strain_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
  [eqv_strain_R]
    type = ElementAverageValue
    variable = eqv_creep_strain_R
    outputs = csv
  []
  [strain_zz]
    type = ElementAverageValue
    variable = strain_yy
    outputs = csv
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_yy
    outputs = csv
  []
  [q]
    type = ElementAverageValue
    variable = eqv_stress
    outputs = csv
  []
  [vol_strain]
    type = ElementAverageValue
    variable = vol_strain_neg   #used parsedaux kernel to turn the vol strain into negative 
    outputs = csv
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it
                           -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
  [superlu]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason -ksp_gmres_modifiedgramschmidt -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-snes_type
                           -snes_atol -snes_rtol -snes_max_it
                           -pc_type -pc_factor_mat_solver_package
                           -snes_linesearch_type'
    petsc_options_value = 'newtonls
                           1e-10 1e-12 50
                           lu superlu_dist
                           l2'
  []
  [asm]
    type = SMP
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-ksp_type
                           -pc_type
                           -sub_pc_type
                           -snes_type -snes_atol -snes_rtol -snes_max_it -snes_linesearch_type
                           -ksp_gmres_restart'
    petsc_options_value = 'fgmres
                           asm
                           ilu
                           newtonls 1e-10 1e-10 120 basic
                           201'
  []
[]
  
[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  automatic_scaling = true
  start_time = 0.0
  end_time =  0.8873456790123455  #200 
  num_steps = 800
  #dt = 0.001
  timestep_tolerance = 1.0e-10
[]
  
[Outputs]
  perf_graph = true
  exodus = true
  [csv]
  type = CSV
  execute_on = 'timestep_end'
  []
[]

(examples/viscoelasticity/RTL2020/BVRTL2020salt5creeptest.i)

# Modified Lemaitre creep model
# See Fig. 7 and the first multistage creep test on Fig.8 of Azabou et al. (2021)
# Parameters
# Units: stress in MPa, time in days, strain in m / m
E = 22126
nu = 0.2
alpha = 0.5812 
A1 = 0.1854
n1 = 2.1012
A2 = 3.7009
n2 = 6.7562
A = 155.6582
n = 11.989
B = 0.01918
m = 2.2195
Tr = 289
Ar = 1725
P = 8.7
P_TCT = 5
Q = 12.7
z = 0.4523
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
  type = GeneratedMesh
  dim = 3
  # nx = 5
  # ny = 10
  # nz = 5
  nx = 1
  ny = 1
  nz = 1
  xmin = 0
  xmax = 65e-03
  ymin = 0
  ymax = 130e-03
  zmin = 0
  zmax = 65e-03
[]
  
[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]
  
[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]
  
[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 313
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_R]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_zz]
    order = CONSTANT
    family = MONOMIAL
  []
[]
  
[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 313
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_R_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_R
    property = eqv_creep_strain_R
    execute_on = 'TIMESTEP_END'
  []
  [strain_zz_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_yy_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_zz_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = z
    index_j = z
    execute_on = 'TIMESTEP_END'
  []
[]
  
[Functions]
  [Q_loading]
    type = ParsedFunction 
    expression = 'if(t<=10,12.7,if(t<=40,15,if(t<=90,20,if(t<=140,22,24))))' 
  []
  [P_loading]
    type = ParsedFunction 
    expression = 'if(t<=10,8.7,if(t<=40,7.5,if(t<=90,5,if(t<=140,4,3))))' 
  []
  [strain_rate]
  type = ParsedFunction
  vars = 'e_dot L'
  vals = '1.0e-06 130e-03'
  expression = 'e_dot*L*t'
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P_TCT} #P_loading, use P_TCT for the triaxial compress. test
    []
    [pressure_front]
      boundary = 'front'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P_TCT} #P_loading
    []
  #  [pressure_top]
  #    boundary = 'top'
  #    displacement_vars = 'disp_x disp_y disp_z'
  #    function = Q_loading
  #  []
  []
  [strain_rate]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 'top'
    function = strain_rate
  []
[]
  
[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} -${Q} -${P}'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = false
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Postprocessors]
   [eqv_strain_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
  [eqv_strain_R]
    type = ElementAverageValue
    variable = eqv_creep_strain_R
    outputs = csv
  []
  [strain_zz]
    type = ElementAverageValue
    variable = strain_yy
    outputs = csv
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_zz
    outputs = csv
  []
  [q]
    type = ElementAverageValue
    variable = eqv_stress
    outputs = csv
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it
                           -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
  [superlu]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason -ksp_gmres_modifiedgramschmidt -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-snes_type
                           -snes_atol -snes_rtol -snes_max_it
                           -pc_type -pc_factor_mat_solver_package
                           -snes_linesearch_type'
    petsc_options_value = 'newtonls
                           1e-10 1e-12 50
                           lu superlu_dist
                           l2'
  []
  [asm]
    type = SMP
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-ksp_type
                           -pc_type
                           -sub_pc_type
                           -snes_type -snes_atol -snes_rtol -snes_max_it -snes_linesearch_type
                           -ksp_gmres_restart'
    petsc_options_value = 'fgmres
                           asm
                           ilu
                           newtonls 1e-10 1e-10 120 basic
                           201'
  []
[]
  
[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  automatic_scaling = true
  start_time = 0.0
  end_time = 200 
  dt = 0.02
  timestep_tolerance = 1.0e-10
[]
  
[Outputs]
  perf_graph = true
  exodus = true
  [csv]
  type = CSV
  execute_on = 'timestep_end'
  []
[]

(examples/viscoelasticity/RTL2020/BVRTL2020salt5triaxialtest2.i)

# Modified Lemaitre creep model
# See the first three figures of Fig.8 in Azabou et al. (2021)
# Parameters
# Units: stress in MPa, time in days, strain in m / m
E = 22126
nu = 0.2
alpha = 0.5812 
A1 = 0.1854
n1 = 2.1012
A2 = 3.7009
n2 = 6.7562
A = 155.6582
n = 11.989
B = 0.01918
m = 2.2195
Tr = 289
Ar = 1725
P = 5 
z = 0.4523
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
  type = GeneratedMesh
  dim = 3
  # nx = 5
  # ny = 10
  # nz = 5
  nx = 1
  ny = 1
  nz = 1
  xmin = 0
  xmax = 65e-03
  ymin = 0
  ymax = 130e-03
  zmin = 0
  zmax = 65e-03
[]
  
[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]
  
[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]
  
[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 293.15
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_L]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_R]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [stress_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [vol_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [vol_strain_neg]
    order = CONSTANT
    family = MONOMIAL
  []
[]
  
[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 293.15
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_L_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_L
    property = eqv_creep_strain_L
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_R_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_R
    property = eqv_creep_strain_R
    execute_on = 'TIMESTEP_END'
  []
  [strain_zz_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [stress_zz_aux]
    type = BVStressComponentAux
    variable = stress_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [vol_strain_aux]
    type = BVVolStrainAux
    variable = vol_strain
    execute_on = 'TIMESTEP_END'
  []
  [vol_strain_neg]
    type = ParsedAux
    coupled_variables = vol_strain 
    expression =  '-vol_strain'  
    variable = vol_strain_neg
  []
[]
  
[Functions]
  [strain_rate]
  type = ParsedFunction
  symbol_names = 'e_dot L'
  symbol_values = '1.0e-05 130e-03'
  expression = '-e_dot*L*t*86400' #converted to per days
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P} 
    []
    [pressure_front]
      boundary = 'front'
      displacement_vars = 'disp_x disp_y disp_z'
      function = ${P} 
    []
  []
  [strain_rate]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 'top'
    function = strain_rate
  []
[]
  
[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} -${P} -${P}'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = true
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Postprocessors]
   [eqv_strain_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [eqv_strain_L]
    type = ElementAverageValue
    variable = eqv_creep_strain_L
    outputs = csv
  []
  [eqv_strain_R]
    type = ElementAverageValue
    variable = eqv_creep_strain_R
    outputs = csv
  []
  [strain_zz]
    type = ElementAverageValue
    variable = strain_yy
    outputs = csv
  []
  [stress_zz]
    type = ElementAverageValue
    variable = stress_yy
    outputs = csv
  []
  [q]
    type = ElementAverageValue
    variable = eqv_stress
    outputs = csv
  []
  [vol_strain]
    type = ElementAverageValue
    variable = vol_strain_neg   #used parsedaux kernel to turn the vol strain into negative 
    outputs = csv
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it
                           -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
  [superlu]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason -ksp_gmres_modifiedgramschmidt -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-snes_type
                           -snes_atol -snes_rtol -snes_max_it
                           -pc_type -pc_factor_mat_solver_package
                           -snes_linesearch_type'
    petsc_options_value = 'newtonls
                           1e-10 1e-12 50
                           lu superlu_dist
                           l2'
  []
  [asm]
    type = SMP
    petsc_options = '-snes_ksp_ew'
    petsc_options_iname = '-ksp_type
                           -pc_type
                           -sub_pc_type
                           -snes_type -snes_atol -snes_rtol -snes_max_it -snes_linesearch_type
                           -ksp_gmres_restart'
    petsc_options_value = 'fgmres
                           asm
                           ilu
                           newtonls 1e-10 1e-10 120 basic
                           201'
  []
[]
  
[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  automatic_scaling = true
  start_time = 0.0
  end_time =  0.8873456790123455  #200 
  num_steps = 800
  #dt = 0.001
  timestep_tolerance = 1.0e-10
[]
  
[Outputs]
  perf_graph = true
  exodus = true
  [csv]
  type = CSV
  execute_on = 'timestep_end'
  []
[]

(examples/viscoelasticity/munson-dawson/munson_dawson.i)

# Input file for purely Lemaitre creep model based on RTL2020 model (Azabou et al. (2021)). 
# Note: Parameter A is set to zero to ensure the Munson-Dawson component is zero.
# Also, volumetric part is set to false and parameter z is set to zero.  
# Parameters
# Units: stress in MPa, time in days, strain in m / m

E = 0.6
nu = 0.000044
alpha = 0.1 
A2 = 0.5
n2 = 4
Ar = 1
Tr = 289
# parameters for Munson-Dawson part
A1 = 0.3
n1 = 3
A = 0.5
n = 5
B = 0.05
m = 5
P = 1
# parameters for volumetric part
z = 0.0
Nz = 0.0241
nz = 1.2644
Mz = 0.024
mz = 1.028

[Mesh]
  type = GeneratedMesh
  dim = 3
  nx = 1
  ny = 1
  nz = 2
  xmin = 0
  xmax = 1
  ymin = 0
  ymax = 1
  zmin = 0
  zmax = 0.1
[]

[Variables]
  [disp_x]
    order = FIRST
    family = LAGRANGE
  []
  [disp_y]
    order = FIRST
    family = LAGRANGE
  []
  [disp_z]
    order = FIRST
    family = LAGRANGE
  []
[]

[Kernels]
  [stress_x]
    type = BVStressDivergence
    component = x
    variable = disp_x
  []
  [stress_y]
    type = BVStressDivergence
    component = y
    variable = disp_y
  []
  [stress_z]
    type = BVStressDivergence
    component = z
    variable = disp_z
  []
[]

[AuxVariables]
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 289
  []
  [eqv_stress]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_strain_rate]
    order = CONSTANT
    family = MONOMIAL
  []
  [strain_yy]
    order = CONSTANT
    family = MONOMIAL
  []
  [eqv_creep_strain_R]
    order = CONSTANT
    family = MONOMIAL
  []
[]

[AuxKernels]
  [temp_aux]
    type = ConstantAux
    variable = temp
    value = 289
    execute_on = 'TIMESTEP_END'
  []
  [eqv_stress_aux]
    type = BVMisesStressAux
    variable = eqv_stress
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_aux]
    type = BVEqvStrainAux
    variable = eqv_strain
    execute_on = 'TIMESTEP_END'
  []
  [eqv_strain_rate_aux]
    type = BVEqvStrainRateAux
    variable = eqv_strain_rate
    execute_on = 'TIMESTEP_END'
  []
  [strain_yy_aux]
    type = BVStrainComponentAux
    variable = strain_yy
    index_i = y
    index_j = y
    execute_on = 'TIMESTEP_END'
  []
  [eqv_creep_strain_R_aux]
    type = ADMaterialRealAux
    variable = eqv_creep_strain_R
    property = eqv_creep_strain_R
    execute_on = 'TIMESTEP_END'
  []
[]

[Functions]
  [Q_loading]
    type = ParsedFunction 
    expression = 'if(t<=15,10,5)' 
  []
[]

[BCs]
  [no_x]
    type = DirichletBC
    variable = disp_x
    boundary = 'left'
    value = 0.0
  []
  [no_y]
    type = DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
  []
  [no_z]
    type = DirichletBC
    variable = disp_z
    boundary = 'front back'
    value = 0.0
  []
  [BVPressure]
    [pressure_right]
      boundary = 'right'
      displacement_vars = 'disp_x disp_y disp_z'
      value = 0.0
    []
    [pressure_top]
      boundary = 'top'
      displacement_vars = 'disp_x disp_y disp_z'
      function = Q_loading
     # value = -10.0
    []
  []
[]

[Materials]
  [elasticity]
    type = BVMechanicalMaterial
    displacements = 'disp_x disp_y disp_z'
    young_modulus = ${E}
    poisson_ratio = ${nu}
    initial_stress = '-${P} ${P} 0.0'
    inelastic_models = 'viscoelastic'
  []
  [viscoelastic]
    type = BVRTL2020ModelUpdate
    volumetric = false
    temperature = temp
    Tr = ${Tr}
    Ar = ${Ar}
    alpha = ${alpha}
    A1 = ${A1}
    n1 = ${n1}
    A2 = ${A2}
    n2 = ${n2}
    A = ${A}
    n = ${n}
    B = ${B}
    m = ${m}
    Nz = ${Nz}
    nz = ${nz}
    Mz = ${Mz}
    mz = ${mz}
    z = ${z}
  []
[]

[Preconditioning]
  active = 'hypre'
  [hypre]
    type = SMP
    full = true
    petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason  -ksp_diagonal_scale -ksp_diagonal_scale_fix'
    petsc_options_iname = '-pc_type -pc_hypre_type
                           -snes_atol -snes_rtol -snes_stol -snes_max_it -snes_linesearch_type'
    petsc_options_value = 'hypre boomeramg
                           1.0e-10 1.0e-12 0 20
                           basic'
  []
[]

[Postprocessors]
  [e]
    type = ElementAverageValue
    variable = eqv_strain
    outputs = csv
  []
  [e_rate]
    type = ElementAverageValue
    variable = eqv_strain_rate
    outputs = csv
  []
  [eqv_strain_R]
    type = ElementAverageValue
    variable = eqv_creep_strain_R
    outputs = csv
  []
[]

[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  start_time = 0.0
  end_time = 30.0
  dt = 0.01
[]

[Outputs]
  perf_graph = true
  execute_on = 'TIMESTEP_END'
  print_linear_residuals = false
  exodus = true
  [csv]
    type = CSV
  []
[]

Overview
Example Input File Syntax
Input Parameters
Input Files