Tensor Mechanics Master Action System

Set up stress divergence kernels with coordinate system aware logic

The TensorMechanics Master Action is a convenience object that simplifies part of the mechanics system setup. It performs

Add StressDivergence Kernels (for the current coordinate system)
Add WeakPlaneStress Kernel (for weak enforcement of the plane stress condition)
Add Strain calculation material (for the chosen strain model)
Correctly set use of displaced mesh
Optional: Setup of displacement variables (with the correct order for the current mesh)
Optional: Add AuxVariables and AuxKernels for various tensor components and quantity outputs
Optional: Set up out-of-plane stress/strain consistently

Constructed MooseObjects

The Tensor Mechanics Master Action is used to construct the kernels, displacement variables, and strain materials in a consistent manner as required for a continuum mechanics simulation simulation. Optionally it generates aux variables and auxkernels to aid in the output of tensor components and scalar quantities.

Table 1: Correspondence Among Action Functionality and MooseObjects for the Tensor Mechanics Master Action

Functionality	Replaced Classes	Associated Parameters
Calculate stress divergence equilibrium for the given coordinate system	StressDivergenceTensors and optionally WeakPlaneStress or StressDivergenceRZTensors or StressDivergenceRSphericalTensors	`displacements` : a string of the displacement field variables
Add the displacement variables	Variables	`add_variables`: boolean
Calculation of strain for the given coordinate system	ComputeFiniteStrain or ComputePlaneFiniteStrain or ComputeAxisymmetric1DFiniteStrain or ComputeAxisymmetricRZFiniteStrain	`strain`: MooseEnum to select finite or strain formulations
	ComputeSmallStrain or ComputePlaneSmallStrain or ComputeAxisymmetric1DSmallStrain or ComputeAxisymmetricRZSmallStrain
	ComputeIncrementalSmallStrain or ComputePlaneIncrementalStrain or ComputeAxisymmetric1DIncrementalStrain or ComputeAxisymmetricRZIncrementalStrain	`incremental` : boolean for using a incremental strain formulation
Add AuxVariables and AuxKernels for various tensor component and quantity outputs	AuxVariables and RankTwoAux or RankTwoScalarAux or RankFourAux	`generate_output`: a string of the quantities to add
Add the optional global strain contribution to the strain calculation	Couples the GlobalStrain system	`global_strain`: name of the material property that computes the global strain tensor

Note that there are many variations for the calculation of the stress divergence and the strain measure. Review the theoretical introduction for the Stress Divergence and the Strain Formulations for more information.

Example Input File Syntax

Subblocks

The subblocks of the Master action are what triggers MOOSE objects to be built. If none of the mechanics is subdomain restricted a single subblock can be used

[./Master]
  [./all]
    strain = FINITE
    add_variables = true
  [../]
[../]

/opt/civet/build_0/moose/modules/tensor_mechanics/test/tests/finite_strain_elastic/finite_strain_elastic_new_test.i

[Mesh]
  type = GeneratedMesh
  dim = 3
  elem_type = HEX8
[]

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

[Functions]
  [./tdisp]
    type = ParsedFunction
    value = '0.01 * t'
  [../]
[]

[Modules]
  [./TensorMechanics]
    [./Master]
      [./all]
        strain = FINITE
        add_variables = true
      [../]
    [../]
  [../]
[]

[BCs]
  [./symmy]
    type = DirichletBC
    variable = disp_y
    boundary = bottom
    value = 0
  [../]
  [./symmx]
    type = DirichletBC
    variable = disp_x
    boundary = left
    value = 0
  [../]
  [./symmz]
    type = DirichletBC
    variable = disp_z
    boundary = back
    value = 0
  [../]
  [./tdisp]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = front
    function = tdisp
  [../]
[]

[Materials]
  [./elasticity_tensor]
    type = ComputeElasticityTensor
    C_ijkl = '1.684e5 0.176e5 0.176e5 1.684e5 0.176e5 1.684e5 0.754e5 0.754e5 0.754e5'
    fill_method = symmetric9
  [../]
  [./stress]
    type = ComputeFiniteStrainElasticStress
  [../]
[]

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

[Executioner]
  type = Transient
  dt = 0.05

  #Preconditioned JFNK (default)
  solve_type = 'PJFNK'

  petsc_options_iname = -pc_hypre_type
  petsc_options_value = boomeramg
  nl_abs_tol = 1e-10
  nl_rel_step_tol = 1e-10
  dtmax = 10.0
  nl_rel_tol = 1e-10
  end_time = 1
  dtmin = 0.05
  num_steps = 10
  nl_abs_step_tol = 1e-10
[]

[Outputs]
  exodus = true
[]

if different mechanics models are needed, multiple subblocks with subdomain restrictions can be used.

[Modules/TensorMechanics/Master]
  # parameters that apply to all subblocks are specified at this level. They
  # can be overwritten in the subblocks.
  add_variables = true
  strain = FINITE
  generate_output = 'stress_xx'

  [./block1]
    # the `block` parameter is only valid insde a subblock.
    block = 1
  [../]
  [./block2]
    block = 2
    # the `additional_generate_output` parameter is also only valid inside a
    # subblock. Values specified here are appended to the `generate_output`
    # parameter values.
    additional_generate_output = 'strain_yy'
  [../]
[]

/opt/civet/build_0/moose/modules/tensor_mechanics/test/tests/action/two_block_new.i

[Mesh]
  [generated_mesh]
    type = GeneratedMeshGenerator
    dim = 2
    nx = 4
    ny = 4
  []
  [block1]
    type = SubdomainBoundingBoxGenerator
    block_id = 1
    bottom_left = '0 0 0'
    top_right = '0.5 1 0'
    input = generated_mesh
  []
  [block2]
    type = SubdomainBoundingBoxGenerator
    block_id = 2
    bottom_left = '0.5 0 0'
    top_right = '1 1 0'
    input = block1
  []
[]

[GlobalParams]
  displacements = 'disp_x disp_y'
[]

[Modules/TensorMechanics/Master]
  # parameters that apply to all subblocks are specified at this level. They
  # can be overwritten in the subblocks.
  add_variables = true
  strain = FINITE
  generate_output = 'stress_xx'

  [./block1]
    # the `block` parameter is only valid insde a subblock.
    block = 1
  [../]
  [./block2]
    block = 2
    # the `additional_generate_output` parameter is also only valid inside a
    # subblock. Values specified here are appended to the `generate_output`
    # parameter values.
    additional_generate_output = 'strain_yy'
  [../]
[]

[AuxVariables]
  [./stress_theta]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./strain_theta]
    order = CONSTANT
    family = MONOMIAL
  [../]
[]

[AuxKernels]
  [./stress_theta]
    type = RankTwoAux
    rank_two_tensor = stress
    index_i = 2
    index_j = 2
    variable = stress_theta
    execute_on = timestep_end
  [../]
  [./strain_theta]
    type = RankTwoAux
    rank_two_tensor = total_strain
    index_i = 2
    index_j = 2
    variable = strain_theta
    execute_on = timestep_end
  [../]
[]

[Materials]
  [./elasticity_tensor]
    type = ComputeIsotropicElasticityTensor
    youngs_modulus = 1e10
    poissons_ratio = 0.345
  [../]
  [./_elastic_stress1]
    type = ComputeFiniteStrainElasticStress
    block = 1
  [../]
  [./_elastic_stress2]
    type = ComputeFiniteStrainElasticStress
    block = 2
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    boundary = 'left'
    variable = disp_x
    value = 0.0
  [../]
  [./top]
    type = DirichletBC
    boundary = 'top'
    variable = disp_y
    value = 0.0
  [../]
  [./right]
    type = DirichletBC
    boundary = 'right'
    variable = disp_x
    value = 0.01
  [../]
  [./bottom]
    type = DirichletBC
    boundary = 'bottom'
    variable = disp_y
    value = 0.01
  [../]
[]

[Debug]
  show_var_residual_norms = true
[]

[Executioner]
  type = Steady

  petsc_options_iname = '-ksp_gmres_restart -pc_type -pc_hypre_type -pc_hypre_boomeramg_max_iter'
  petsc_options_value = '  201               hypre    boomeramg      10'

  line_search = 'none'

  nl_rel_tol = 5e-9
  nl_abs_tol = 1e-10
  nl_max_its = 15

  l_tol = 1e-3
  l_max_its = 50
[]

[Outputs]
  exodus = true
[]

Parameters supplied at the [Modules/TensorMechanics/Master] level act as defaults for the Master action subblocks.

Input Parameters

displacementsThe nonlinear displacement variables for the problem
C++ Type:std::vector
Options:
Description:The nonlinear displacement variables for the problem

Required Parameters

active__all__ If specified only the blocks named will be visited and made active
Default:__all__
C++ Type:std::vector
Options:
Description:If specified only the blocks named will be visited and made active
add_variablesFalseAdd the displacement variables
Default:False
C++ Type:bool
Options:
Description:Add the displacement variables
base_nameMaterial property base name
C++ Type:std::string
Options:
Description:Material property base name
decomposition_methodTaylorExpansionMethods to calculate the finite strain and rotation increments
Default:TaylorExpansion
C++ Type:MooseEnum
Options:TaylorExpansion EigenSolution
Description:Methods to calculate the finite strain and rotation increments
eigenstrain_namesList of eigenstrains to be applied in this strain calculation
C++ Type:std::vector
Options:
Description:List of eigenstrains to be applied in this strain calculation
extra_vector_tagsThe tag names for extra vectors that residual data should be saved into
C++ Type:std::vector
Options:
Description:The tag names for extra vectors that residual data should be saved into
global_strainName of the global strain material to be applied in this strain calculation. The global strain tensor is constant over the whole domain and allows visualization of the deformed shape with the periodic BC
C++ Type:MaterialPropertyName
Options:
Description:Name of the global strain material to be applied in this strain calculation. The global strain tensor is constant over the whole domain and allows visualization of the deformed shape with the periodic BC
inactiveIf specified blocks matching these identifiers will be skipped.
C++ Type:std::vector
Options:
Description:If specified blocks matching these identifiers will be skipped.
incrementalFalseUse incremental or total strain
Default:False
C++ Type:bool
Options:
Description:Use incremental or total strain
strainSMALLStrain formulation
Default:SMALL
C++ Type:MooseEnum
Options:SMALL FINITE
Description:Strain formulation
strain_base_nameThe base name used for the strain. If not provided, it will be set equal to base_name
C++ Type:std::string
Options:
Description:The base name used for the strain. If not provided, it will be set equal to base_name
temperatureThe temperature
C++ Type:VariableName
Options:
Description:The temperature
use_automatic_differentiationFalseFlag to use automatic differentiation (AD) objects when possible
Default:False
C++ Type:bool
Options:
Description:Flag to use automatic differentiation (AD) objects when possible
use_displaced_meshFalseWhether to use displaced mesh in the kernels
Default:False
C++ Type:bool
Options:
Description:Whether to use displaced mesh in the kernels
use_finite_deform_jacobianFalseJacobian for corrotational finite strain
Default:False
C++ Type:bool
Options:
Description:Jacobian for corrotational finite strain
volumetric_locking_correctionFalseFlag to correct volumetric locking
Default:False
C++ Type:bool
Options:
Description:Flag to correct volumetric locking

Optional Parameters

additional_generate_outputAdd scalar quantity output for stress and/or strain (will be appended to the list in `generate_output`)
C++ Type:MultiMooseEnum
Options:creep_strain_xx creep_strain_xy creep_strain_xz creep_strain_yx creep_strain_yy creep_strain_yz creep_strain_zx creep_strain_zy creep_strain_zz elastic_strain_xx elastic_strain_xy elastic_strain_xz elastic_strain_yx elastic_strain_yy elastic_strain_yz elastic_strain_zx elastic_strain_zy elastic_strain_zz plastic_strain_xx plastic_strain_xy plastic_strain_xz plastic_strain_yx plastic_strain_yy plastic_strain_yz plastic_strain_zx plastic_strain_zy plastic_strain_zz strain_xx strain_xy strain_xz strain_yx strain_yy strain_yz strain_zx strain_zy strain_zz stress_xx stress_xy stress_xz stress_yx stress_yy stress_yz stress_zx stress_zy stress_zz firstinv_stress firstinv_strain hydrostatic_stress max_principal_stress mid_principal_stress min_principal_stress secondinv_stress secondinv_strain thirdinv_stress thirdinv_strain vonmises_stress
Description:Add scalar quantity output for stress and/or strain (will be appended to the list in `generate_output`)
generate_outputAdd scalar quantity output for stress and/or strain
C++ Type:MultiMooseEnum
Options:creep_strain_xx creep_strain_xy creep_strain_xz creep_strain_yx creep_strain_yy creep_strain_yz creep_strain_zx creep_strain_zy creep_strain_zz elastic_strain_xx elastic_strain_xy elastic_strain_xz elastic_strain_yx elastic_strain_yy elastic_strain_yz elastic_strain_zx elastic_strain_zy elastic_strain_zz plastic_strain_xx plastic_strain_xy plastic_strain_xz plastic_strain_yx plastic_strain_yy plastic_strain_yz plastic_strain_zx plastic_strain_zy plastic_strain_zz strain_xx strain_xy strain_xz strain_yx strain_yy strain_yz strain_zx strain_zy strain_zz stress_xx stress_xy stress_xz stress_yx stress_yy stress_yz stress_zx stress_zy stress_zz firstinv_stress firstinv_strain hydrostatic_stress max_principal_stress mid_principal_stress min_principal_stress secondinv_stress secondinv_strain thirdinv_stress thirdinv_strain vonmises_stress
Description:Add scalar quantity output for stress and/or strain

Output Parameters

blockThe list of ids of the blocks (subdomain) that the stress divergence kernels will be applied to
C++ Type:std::vector
Options:
Description:The list of ids of the blocks (subdomain) that the stress divergence kernels will be applied to
diag_save_inThe displacement diagonal preconditioner terms
C++ Type:std::vector
Options:
Description:The displacement diagonal preconditioner terms
save_inThe displacement residuals
C++ Type:std::vector
Options:
Description:The displacement residuals

Advanced Parameters

out_of_plane_directionzThe direction of the out-of-plane strain.
Default:z
C++ Type:MooseEnum
Options:x y z
Description:The direction of the out-of-plane strain.
out_of_plane_pressure0Function used to prescribe pressure in the out-of-plane direction (y for 1D Axisymmetric or z for 2D Cartesian problems)
Default:0
C++ Type:FunctionName
Options:
Description:Function used to prescribe pressure in the out-of-plane direction (y for 1D Axisymmetric or z for 2D Cartesian problems)
out_of_plane_strainVariable for the out-of-plane strain for plane stress models
C++ Type:VariableName
Options:
Description:Variable for the out-of-plane strain for plane stress models
planar_formulationNONEOut-of-plane stress/strain formulation
Default:NONE
C++ Type:MooseEnum
Options:NONE WEAK_PLANE_STRESS PLANE_STRAIN GENERALIZED_PLANE_STRAIN
Description:Out-of-plane stress/strain formulation
pressure_factor1Scale factor applied to prescribed pressure
Default:1
C++ Type:double
Options:
Description:Scale factor applied to prescribed pressure
scalar_out_of_plane_strainScalar variable for the out-of-plane strain (in y direction for 1D Axisymmetric or in z direction for 2D Cartesian problems)
C++ Type:VariableName
Options:
Description:Scalar variable for the out-of-plane strain (in y direction for 1D Axisymmetric or in z direction for 2D Cartesian problems)

Out-Of-Plane Stress/Strain Parameters

Associated Actions

Available Actions

Tensor Mechanics App
CommonTensorMechanicsAction
TensorMechanicsActionSet up stress divergence kernels with coordinate system aware logic

Constructed MooseObjects
Example Input File Syntax
Input Parameters
Associated Actions
Available Actions

Application Usage

Physics and Syntax

Application Development

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