Compute Variable Isotropic Elasticity Tensor

Compute an isotropic elasticity tensor for elastic constants that change as a function of material properties

Description

This model computes an elasticity tensor for which the elastic moduli, prescribed in terms of the Young's modulus and Poisson's ratio, vary as defined by user-specified material properties. Every time this material is evaluated, the full tensor is updated to reflect the current values of those elastic constants.

Example Input File Syntax

[./elasticity_tensor]
  type = ComputeVariableIsotropicElasticityTensor
  args = temp
  youngs_modulus = youngs_modulus
  poissons_ratio = poissons_ratio
[../]

Input Parameters

argsVariable dependence for the Young's Modulus and Poisson's Ratio materials
C++ Type:std::vector<VariableName>
Controllable:No
Description:Variable dependence for the Young's Modulus and Poisson's Ratio materials
poissons_ratioName of material property defining the Poisson's Ratio
C++ Type:MaterialPropertyName
Controllable:No
Description:Name of material property defining the Poisson's Ratio
youngs_modulusName of material property defining the Young's Modulus
C++ Type:MaterialPropertyName
Controllable:No
Description:Name of material property defining the Young's Modulus

Required Parameters

base_nameOptional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases
C++ Type:std::string
Controllable:No
Description:Optional parameter that allows the user to define multiple mechanics material systems on the same block, i.e. for multiple phases
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
computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
Default:True
C++ Type:bool
Controllable:No
Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
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
Controllable:No
Description:An optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
elasticity_tensor_prefactorOptional function to use as a scalar prefactor on the elasticity tensor.
C++ Type:FunctionName
Controllable:No
Description:Optional function to use as a scalar prefactor on the elasticity tensor.
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
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.

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
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

(../moose/modules/combined/test/tests/thermal_elastic/thermal_elastic.i)

# Patch Test

# This test is designed to compute constant xx, yy, zz, xy, yz, and xz
#  stress on a set of irregular hexes.  The mesh is composed of one
#  block with seven elements.  The elements form a unit cube with one
#  internal element.  There is a nodeset for each exterior node.

# The cube is displaced by 1e-6 units in x, 2e-6 in y, and 3e-6 in z.
#  The faces are sheared as well (1e-6, 2e-6, and 3e-6 for xy, yz, and
#  zx).  This gives a uniform strain/stress state for all six unique
#  tensor components.  This displacement is again applied in the second
#  step.

# With Young's modulus at 1e6 and Poisson's ratio at 0, the shear
#  modulus is 5e5 (G=E/2/(1+nu)).  Therefore, for the mechanical strain,
#
#  stress xx = 1e6 * 1e-6 = 1
#  stress yy = 1e6 * 2e-6 = 2
#  stress zz = 1e6 * 3e-6 = 3
#  stress xy = 2 * 5e5 * 1e-6 / 2 = 0.5
#             (2 * G   * gamma_xy / 2 = 2 * G * epsilon_xy)
#  stress yz = 2 * 5e5 * 2e-6 / 2 = 1
#  stress zx = 2 * 5e5 * 3e-6 / 2 = 1.5

# Young's modulus is a function of temperature for this test.  The
#  temperature changes from 100 to 500.  The Young's modulus drops
#  due to that temperature change from 1e6 to 6e5.

# Poisson's ratio also is a function of temperature and changes from
#  0 to 0.25.

# At the end of the temperature ramp, E=6e5 and nu=0.25.  This gives
#  G=2.4e=5.  lambda=E*nu/(1+nu)/(1-2*nu)=2.4E5.  The final stress
#  is therefore

#  stress xx = 2.4e5 * 12e-6 + 2*2.4e5*2e-6 = 3.84
#  stress yy = 2.4e5 * 12e-6 + 2*2.4e5*4e-6 = 4.80
#  stress zz = 2.4e5 * 12e-6 + 2*2.4e5*6e-6 = 5.76
#  stress xy = 2 * 2.4e5 * 2e-6 / 2 = 0.48
#             (2 * G   * gamma_xy / 2 = 2 * G * epsilon_xy)
#  stress yz = 2 * 2.4e5 * 4e-6 / 2 = 0.96
#  stress xz = 2 * 2.4e5 * 6e-6 / 2 = 1.44

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

[Mesh]
  file = thermal_elastic.e
[]

[Functions]
  [./ramp1]
    type = PiecewiseLinear
    x = '0. 1. 2.'
    y = '0. 1. 2.'
    scale_factor = 1e-6
  [../]
  [./ramp2]
    type = PiecewiseLinear
    x = '0. 1. 2.'
    y = '0. 1. 2.'
    scale_factor = 2e-6
  [../]
  [./ramp3]
    type = PiecewiseLinear
    x = '0. 1. 2.'
    y = '0. 1. 2.'
    scale_factor = 3e-6
  [../]
  [./ramp4]
    type = PiecewiseLinear
    x = '0. 1. 2.'
    y = '0. 1. 2.'
    scale_factor = 4e-6
  [../]
  [./ramp6]
    type = PiecewiseLinear
    x = '0. 1. 2.'
    y = '0. 1. 2.'
    scale_factor = 6e-6
  [../]
  [./tempFunc]
    type = PiecewiseLinear
    x = '0     1     2'
    y = '100.0 100.0 500.0'
  [../]
[]

[Variables]
  [./temp]
    initial_condition = 100.0
  [../]
[]

[Modules/TensorMechanics/Master]
  [./all]
    add_variables = true
    generate_output = 'stress_xx stress_yy stress_zz stress_xy stress_xz stress_yz'
    strain = FINITE
  [../]
[]

[Kernels]
  [./heat]
    type = Diffusion
    variable = temp
  [../]
[]

[BCs]
  [./node1_x]
    type = DirichletBC
    variable = disp_x
    boundary = 1
    value = 0.0
  [../]
  [./node1_y]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 1
    function = ramp2
  [../]
  [./node1_z]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 1
    function = ramp3
  [../]

  [./node2_x]
    type = FunctionDirichletBC
    variable = disp_x
    boundary = 2
    function = ramp1
  [../]
  [./node2_y]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 2
    function = ramp2
  [../]
  [./node2_z]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 2
    function = ramp6
  [../]

  [./node3_x]
    type = FunctionDirichletBC
    variable = disp_x
    boundary = 3
    function = ramp1
  [../]
  [./node3_y]
    type = DirichletBC
    variable = disp_y
    boundary = 3
    value = 0.0
  [../]
  [./node3_z]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 3
    function = ramp3
  [../]

  [./node4_x]
    type = DirichletBC
    variable = disp_x
    boundary = 4
    value = 0.0
  [../]
  [./node4_y]
    type = DirichletBC
    variable = disp_y
    boundary = 4
    value = 0.0
  [../]
  [./node4_z]
    type = DirichletBC
    variable = disp_z
    boundary = 4
    value = 0.0
  [../]

  [./node5_x]
    type = FunctionDirichletBC
    variable = disp_x
    boundary = 5
    function = ramp1
  [../]
  [./node5_y]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 5
    function = ramp4
  [../]
  [./node5_z]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 5
    function = ramp3
  [../]

  [./node6_x]
    type = FunctionDirichletBC
    variable = disp_x
    boundary = 6
    function = ramp2
  [../]
  [./node6_y]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 6
    function = ramp4
  [../]
  [./node6_z]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 6
    function = ramp6
  [../]

  [./node7_x]
    type = FunctionDirichletBC
    variable = disp_x
    boundary = 7
    function = ramp2
  [../]
  [./node7_y]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 7
    function = ramp2
  [../]
  [./node7_z]
    type = FunctionDirichletBC
    variable = disp_z
    boundary = 7
    function = ramp3
  [../]

  [./node8_x]
    type = FunctionDirichletBC
    variable = disp_x
    boundary = 8
    function = ramp1
  [../]
  [./node8_y]
    type = FunctionDirichletBC
    variable = disp_y
    boundary = 8
    function = ramp2
  [../]
  [./node8_z]
    type = DirichletBC
    variable = disp_z
    boundary = 8
    value = 0.0
  [../]

  [./temp]
    type = FunctionDirichletBC
    variable = temp
    boundary = '10 12'
    function = tempFunc
  [../]
[]

[Materials]
  [./youngs_modulus]
    type = PiecewiseLinearInterpolationMaterial
    x = '100 500'
    y = '1e6 6e5'
    property = youngs_modulus
    variable = temp
  [../]
  [./poissons_ratio]
    type = PiecewiseLinearInterpolationMaterial
    x = '100 500'
    y = '0   0.25'
    property = poissons_ratio
    variable = temp
  [../]

  [./elasticity_tensor]
    type = ComputeVariableIsotropicElasticityTensor
    args = temp
    youngs_modulus = youngs_modulus
    poissons_ratio = poissons_ratio
  [../]

  [./stress]
    type = ComputeFiniteStrainElasticStress
  [../]
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'

  nl_rel_tol = 1e-9
  nl_abs_tol = 1e-9

  l_max_its = 20

  start_time = 0.0
  dt = 1.0
  end_time = 2.0
[]

[Outputs]
  exodus = true
[]