LinearElasticTruss

Computes the linear elastic strain for a truss element

Description

This class computes the elastic stretch for a truss element by removing the stretch due to thermal expansion from the total stretch. This elastic stretch and Young's modulus are then used to compute the axial stress for the truss element in the truss local coordinate system.

Input Parameters

displacementsThe displacements appropriate for the simulation geometry and coordinate system
C++ Type:std::vector
Options:
Description:The displacements appropriate for the simulation geometry and coordinate system

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
Options:
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 block ids (SubdomainID) that this object will be applied
C++ Type:std::vector
Options:
Description:The list of block ids (SubdomainID) that this object will be applied
boundaryThe list of boundary IDs from the mesh where this boundary condition applies
C++ Type:std::vector
Options:
Description:The list of boundary IDs from the mesh where this boundary condition 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
Options:
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 computeSubdomainProperties() 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
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 computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
temperature273.0Temperature in Kelvin
Default:273.0
C++ Type:std::vector
Options:
Description:Temperature in Kelvin
temperature_ref273Reference temperature for thermal expansion in K
Default:273
C++ Type:double
Options:
Description:Reference temperature for thermal expansion in K
thermal_expansion_coeff0Thermal expansion coefficient in 1/K
Default:0
C++ Type:double
Options:
Description:Thermal expansion coefficient in 1/K
youngs_modulusVariable containing Young's modulus
C++ Type:std::vector
Options:
Description:Variable containing Young's modulus

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector
Options:
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
Description:Set the enabled status of the MooseObject.
implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Options:
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
Options:
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
Options:
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)
C++ Type:std::vector
Options:
Description:List of material properties, from this material, to output (outputs must also be defined to an output type)
outputsnone Vector of output names were you would like to restrict the output of variables(s) associated with this object
Default:none
C++ Type:std::vector
Options:
Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object

Outputs Parameters

Input Files

modules/tensor_mechanics/test/tests/truss/truss_2d.i
modules/tensor_mechanics/test/tests/truss/truss_hex_action.i
modules/tensor_mechanics/test/tests/truss/truss_2d_action.i
modules/tensor_mechanics/test/tests/truss/truss_3d_action.i
modules/tensor_mechanics/test/tests/truss/truss_3d.i
modules/tensor_mechanics/test/tests/truss/truss_hex.i

modules/tensor_mechanics/test/tests/truss/truss_2d.i

#
# Truss in two dimensional space
#
# The truss is made of five equilateral triangles supported at each end.
# The truss starts at (0,0).  At (1,0), there is a point load of 25.
# The reactions are therefore
#  Ryleft  = 2/3 * 25 = 16.7
#  Ryright = 1/3 * 25 = 8.33
# The area of each member is 0.8.
# Statics gives the stress in each member.  For example, for element 6 (from
#   (0,0) to (1/2,sqrt(3)/2)), the force is
#   f = 2/3 * 25 * 2/sqrt(3) = 100/3/sqrt(3) (compressive)
#   and the stress is
#   s = -100/3/sqrt(3)/0.8 = -24.06
#

[Mesh]
  type = FileMesh
  file = truss_2d.e
  displacements = 'disp_x disp_y'
[]

[Variables]
  [./disp_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./disp_y]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[AuxVariables]
  [./axial_stress]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_over_l]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./area]
    order = CONSTANT
    family = MONOMIAL
#    initial_condition = 1.0
  [../]
  [./react_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./x2]
    type = PiecewiseLinear
    x = '0  1 2 3'
    y = '0 .5 1 1'
  [../]
  [./y2]
    type = PiecewiseLinear
    x = '0 1  2 3'
    y = '0 0 .5 1'
  [../]
[]

[BCs]
  [./fixx1]
    type = DirichletBC
    variable = disp_x
    boundary = 1
    value = 0
  [../]
  [./fixy1]
    type = DirichletBC
    variable = disp_y
    boundary = 1
    value = 0
  [../]

  [./fixy4]
    type = DirichletBC
    variable = disp_y
    boundary = 4
    value = 0
  [../]
[]

[DiracKernels]
  [./pull]
    type = ConstantPointSource
    value = -25
    point = '1 0 0'
    variable = disp_y
  [../]
[]

[AuxKernels]
  [./axial_stress]
    type = MaterialRealAux
    block = 1
    property = axial_stress
    variable = axial_stress
  [../]
  [./e_over_l]
    type = MaterialRealAux
    block = 1
    property = e_over_l
    variable = e_over_l
  [../]
  [./area]
    type = ConstantAux
    block = 1
    variable = area
    value = 0.8
    execute_on = 'initial timestep_begin'
  [../]
[]

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

[Executioner]
  type = Transient

  solve_type = PJFNK

  petsc_options_iname = '-pc_type -ksp_gmres_restart'
  petsc_options_value = 'jacobi   101'

  nl_max_its = 15
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-10

  dt = 1
  num_steps = 1
  end_time = 1
[]

[Kernels]
  [./solid_x]
    type = StressDivergenceTensorsTruss
    block = 1
    displacements = 'disp_x disp_y'
    component = 0
    variable = disp_x
    area = area
    save_in = react_x
  [../]
  [./solid_y]
    type = StressDivergenceTensorsTruss
    block = 1
    displacements = 'disp_x disp_y'
    component = 1
    variable = disp_y
    area = area
    save_in = react_y
  [../]
[]

[Materials]
  [./linelast]
    type = LinearElasticTruss
    block = 1
    youngs_modulus = 1e6
    displacements = 'disp_x disp_y'
  [../]
[]

[Outputs]
  exodus = true
[]

modules/tensor_mechanics/test/tests/truss/truss_hex_action.i

# This test is designed to check
# whether truss element works well with other multi-dimensional element
# e.g. the hex element in this case, by assigning different block number
# to different types of elements.
[Mesh]
  type = FileMesh
  file = truss_hex.e
  displacements = 'disp_x disp_y disp_z'
[]

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

[AuxVariables]
  [./axial_stress]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_over_l]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./area]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./react_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./x2]
    type = PiecewiseLinear
    x = '0  1 2 3'
    y = '0 .5 1 1'
  [../]
  [./y2]
    type = PiecewiseLinear
    x = '0 1  2 3'
    y = '0 0 .5 1'
  [../]
[]

[BCs]
  [./fixx1]
    type = DirichletBC
    variable = disp_x
    boundary = 1
    value = 0.0
  [../]
  [./fixy1]
    type = DirichletBC
    variable = disp_y
    boundary = 1
    value = 0
  [../]
  [./fixz1]
    type = DirichletBC
    variable = disp_z
    boundary = 1
    value = 0
  [../]

  [./fixx2]
    type = DirichletBC
    variable = disp_x
    boundary = 2
    value = 0
  [../]
  [./fixz2]
    type = DirichletBC
    variable = disp_z
    boundary = 2
    value = 0
  [../]

  [./fixDummyHex_x]
    type = DirichletBC
    variable = disp_x
    boundary = 1000
    value = 0
  [../]

  [./fixDummyHex_y]
    type = DirichletBC
    variable = disp_y
    boundary = 1000
    value = 0
  [../]

  [./fixDummyHex_z]
    type = DirichletBC
    variable = disp_z
    boundary = 1000
    value = 0
  [../]
[]

[DiracKernels]
  [./pull]
    type = ConstantPointSource
    value = -25
    point = '0 -2 0'
    variable = disp_y
  [../]
[]

[AuxKernels]
  [./axial_stress]
    type = MaterialRealAux
    block = '1 2'
    property = axial_stress
    variable = axial_stress
  [../]
  [./e_over_l]
    type = MaterialRealAux
    block = '1 2'
    property = e_over_l
    variable = e_over_l
  [../]
  [./area1]
    type = ConstantAux
    block = 1
    variable = area
    value = 1.0
    execute_on = 'initial timestep_begin'
  [../]
  [./area2]
    type = ConstantAux
    block = 2
    variable = area
    value = 0.25
    execute_on = 'initial timestep_begin'
  [../]
[]

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

[Executioner]
  type = Transient

  solve_type = PJFNK

  petsc_options_iname = '-pc_type -ksp_gmres_restart'
  petsc_options_value = 'jacobi   101'

  nl_max_its = 15
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-10

  dt = 1
  num_steps = 1
  end_time = 1
[]

[Kernels]
  [./TensorMechanics]
    block = 1000
    displacements = 'disp_x disp_y disp_z'
  [../]
[]

[Modules/TensorMechanics/LineElementMaster]
   [./block]
     truss = true
     displacements = 'disp_x disp_y disp_z'

     area = area

     block = '1 2'
     save_in = 'react_x react_y react_z'
   [../]
[]

[Materials]
   [./elasticity_tensor]
    type = ComputeIsotropicElasticityTensor
    block = 1000
    youngs_modulus = 1e6
    poissons_ratio = 0
  [../]
  [./strain]
    type = ComputeSmallStrain
    block = 1000
    displacements = 'disp_x disp_y disp_z'
  [../]
  [./stress]
    type = ComputeLinearElasticStress
    block = 1000
  [../]
  [./linelast]
    type = LinearElasticTruss
    block = '1 2'
    displacements = 'disp_x disp_y disp_z'
    youngs_modulus = 1e6
  [../]
[]

[Outputs]
  file_base = 'truss_hex_out'
  exodus = true
[]

modules/tensor_mechanics/test/tests/truss/truss_2d_action.i

#
# Truss in two dimensional space
#
# The truss is made of five equilateral triangles supported at each end.
# The truss starts at (0,0).  At (1,0), there is a point load of 25.
# The reactions are therefore
#  Ryleft  = 2/3 * 25 = 16.7
#  Ryright = 1/3 * 25 = 8.33
# The area of each member is 0.8.
# Statics gives the stress in each member.  For example, for element 6 (from
#   (0,0) to (1/2,sqrt(3)/2)), the force is
#   f = 2/3 * 25 * 2/sqrt(3) = 100/3/sqrt(3) (compressive)
#   and the stress is
#   s = -100/3/sqrt(3)/0.8 = -24.06
#

[Mesh]
  type = FileMesh
  file = truss_2d.e
  displacements = 'disp_x disp_y'
[]

[AuxVariables]
  [./axial_stress]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_over_l]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./area]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./react_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./x2]
    type = PiecewiseLinear
    x = '0  1 2 3'
    y = '0 .5 1 1'
  [../]
  [./y2]
    type = PiecewiseLinear
    x = '0 1  2 3'
    y = '0 0 .5 1'
  [../]
[]

[BCs]
  [./fixx1]
    type = DirichletBC
    variable = disp_x
    boundary = 1
    value = 0
  [../]
  [./fixy1]
    type = DirichletBC
    variable = disp_y
    boundary = 1
    value = 0
  [../]

  [./fixy4]
    type = DirichletBC
    variable = disp_y
    boundary = 4
    value = 0
  [../]
[]

[DiracKernels]
  [./pull]
    type = ConstantPointSource
    value = -25
    point = '1 0 0'
    variable = disp_y
  [../]
[]

[AuxKernels]
  [./axial_stress]
    type = MaterialRealAux
    block = 1
    property = axial_stress
    variable = axial_stress
  [../]
  [./e_over_l]
    type = MaterialRealAux
    block = 1
    property = e_over_l
    variable = e_over_l
  [../]
  [./area]
    type = ConstantAux
    block = 1
    variable = area
    value = 0.8
    execute_on = 'initial timestep_begin'
  [../]
[]

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

[Executioner]
  type = Transient

  solve_type = PJFNK

  petsc_options_iname = '-pc_type -ksp_gmres_restart'
  petsc_options_value = 'jacobi   101'

  nl_max_its = 15
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-10

  dt = 1
  num_steps = 1
  end_time = 1
[]

[Modules/TensorMechanics/LineElementMaster]
  [./block]
    truss = true
    add_variables = true
    displacements = 'disp_x disp_y'

#    area = area # commented out for error check

    block = 1
    save_in = 'react_x react_y'
  [../]
[]

[Materials]
  [./linelast]
    type = LinearElasticTruss
    block = 1
    youngs_modulus = 1e6
    displacements = 'disp_x disp_y'
  [../]
[]

[Outputs]
  file_base = 'truss_2d_out'
  exodus = true
[]

modules/tensor_mechanics/test/tests/truss/truss_3d_action.i

[Mesh]
  type = FileMesh
  file = truss_3d.e
  displacements = 'disp_x disp_y disp_z'
[]

[AuxVariables]
 [./axial_stress]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_over_l]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./area]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./react_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./x2]
    type = PiecewiseLinear
    x = '0  1 2 3'
    y = '0 .5 1 1'
  [../]
  [./y2]
    type = PiecewiseLinear
    x = '0 1  2 3'
    y = '0 0 .5 1'
  [../]
[]

[BCs]
  [./fixx1]
    type = DirichletBC
    variable = disp_x
    preset = false
    boundary = 1
    value = 0.0
  [../]
  [./fixx2]
    type = FunctionDirichletBC
    variable = disp_x
    preset = false
    boundary = 2
    function = x2
  [../]
  [./fixx3]
    type = DirichletBC
    variable = disp_x
    preset = false
    boundary = 3
    value = 0.0
  [../]
  [./fixy1]
    type = DirichletBC
    variable = disp_y
    preset = false
    boundary = 1
    value = 0
  [../]
  [./fixy2]
    type = FunctionDirichletBC
    variable = disp_y
    preset = false
    boundary = 2
    function = y2
  [../]
  [./fixy3]
    type = DirichletBC
    variable = disp_y
    preset = false
    boundary = 3
    value = 0
  [../]
  [./fixz1]
    type = DirichletBC
    variable = disp_z
    preset = false
    boundary = 1
    value = 0
  [../]
  [./fixz2]
    type = DirichletBC
    variable = disp_z
    preset = false
    boundary = 2
    value = 0
  [../]
  [./fixz3]
    type = DirichletBC
    variable = disp_z
    preset = false
    boundary = 3
    value = 0
  [../]
[]

[AuxKernels]
  [./axial_stress]
    type = MaterialRealAux
    block = '1 2'
    property = axial_stress
    variable = axial_stress
  [../]
  [./e_over_l]
    type = MaterialRealAux
    block = '1 2'
    property = e_over_l
    variable = e_over_l
  [../]
  [./area]
    type = ConstantAux
    block = '1 2'
    variable = area
    value = 1.0
    execute_on = 'initial timestep_begin'
  [../]
[]

[Executioner]
  type = Transient
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -ksp_gmres_restart'
  petsc_options_value = 'jacobi   101'
  line_search = 'none'

  nl_max_its = 15
  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-10

  dt = 1
  num_steps = 3
  end_time = 3
[]

[Modules/TensorMechanics/LineElementMaster]
  [./block]
    truss = true
    add_variables = true
    displacements = 'disp_x disp_y disp_z'

    area = area

    block = '1 2'

    save_in = 'react_x react_y react_z'
  [../]
[]

[Materials]
  [./linelast]
    type = LinearElasticTruss
    block = '1 2'
    youngs_modulus = 1e6
    displacements = 'disp_x disp_y disp_z'
  [../]
[]

[Outputs]
  file_base = 'truss_3d_out'
  exodus = true
[]

modules/tensor_mechanics/test/tests/truss/truss_3d.i

[Mesh]
  type = FileMesh
  file = truss_3d.e
  displacements = 'disp_x disp_y disp_z'
[]

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

[AuxVariables]
 [./axial_stress]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_over_l]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./area]
    order = CONSTANT
    family = MONOMIAL
#    initial_condition = 1.0
  [../]
  [./react_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./x2]
    type = PiecewiseLinear
    x = '0  1 2 3'
    y = '0 .5 1 1'
  [../]
  [./y2]
    type = PiecewiseLinear
    x = '0 1  2 3'
    y = '0 0 .5 1'
  [../]
[]

[BCs]
  [./fixx1]
    type = DirichletBC
    variable = disp_x
    preset = false
    boundary = 1
    value = 0.0
  [../]
  [./fixx2]
    type = FunctionDirichletBC
    variable = disp_x
    preset = false
    boundary = 2
    function = x2
  [../]
  [./fixx3]
    type = DirichletBC
    variable = disp_x
    preset = false
    boundary = 3
    value = 0.0
  [../]
  [./fixy1]
    type = DirichletBC
    variable = disp_y
    preset = false
    boundary = 1
    value = 0
  [../]
  [./fixy2]
    type = FunctionDirichletBC
    variable = disp_y
    preset = false
    boundary = 2
    function = y2
  [../]
  [./fixy3]
    type = DirichletBC
    variable = disp_y
    preset = false
    boundary = 3
    value = 0
  [../]
  [./fixz1]
    type = DirichletBC
    variable = disp_z
    preset = false
    boundary = 1
    value = 0
  [../]
  [./fixz2]
    type = DirichletBC
    variable = disp_z
    preset = false
    boundary = 2
    value = 0
  [../]
  [./fixz3]
    type = DirichletBC
    variable = disp_z
    preset = false
    boundary = 3
    value = 0
  [../]
[]

[AuxKernels]
  [./axial_stress]
    type = MaterialRealAux
    block = '1 2'
    property = axial_stress
    variable = axial_stress
  [../]
  [./e_over_l]
    type = MaterialRealAux
    block = '1 2'
    property = e_over_l
    variable = e_over_l
  [../]
  [./area]
    type = ConstantAux
    block = '1 2'
    variable = area
    value = 1.0
    execute_on = 'initial timestep_begin'
  [../]
[]

[Executioner]
  type = Transient
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -ksp_gmres_restart'
  petsc_options_value = 'jacobi   101'
  line_search = 'none'

  nl_max_its = 15
  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-10

  dt = 1
  num_steps = 3
  end_time = 3
[]

[Kernels]
  [./solid_x]
    type = StressDivergenceTensorsTruss
    block = '1 2'
    displacements = 'disp_x disp_y disp_z'
    component = 0
    variable = disp_x
    area = area
    save_in = react_x
  [../]
  [./solid_y]
    type = StressDivergenceTensorsTruss
    block = '1 2'
    displacements = 'disp_x disp_y disp_z'
    component = 1
    variable = disp_y
    area = area
    save_in = react_y
  [../]
  [./solid_z]
    type = StressDivergenceTensorsTruss
    block = '1 2'
    displacements = 'disp_x disp_y disp_z'
    component = 2
    variable = disp_z
    area = area
    save_in = react_z
  [../]
[]

[Materials]
  [./linelast]
    type = LinearElasticTruss
    block = '1 2'
    youngs_modulus = 1e6
    displacements = 'disp_x disp_y disp_z'
  [../]
[]

[Outputs]
  exodus = true
[]

modules/tensor_mechanics/test/tests/truss/truss_hex.i

# This test is designed to check
# whether truss element works well with other multi-dimensional element
# e.g. the hex element in this case, by assigning different brock number
# to different types of elements.
[Mesh]
  type = FileMesh
  file = truss_hex.e
  displacements = 'disp_x disp_y disp_z'
[]

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

[AuxVariables]
  [./axial_stress]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./e_over_l]
    order = CONSTANT
    family = MONOMIAL
  [../]
  [./area]
    order = CONSTANT
    family = MONOMIAL
#    initial_condition = 1.0
  [../]
  [./react_x]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_y]
    order = FIRST
    family = LAGRANGE
  [../]
  [./react_z]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./x2]
    type = PiecewiseLinear
    x = '0  1 2 3'
    y = '0 .5 1 1'
  [../]
  [./y2]
    type = PiecewiseLinear
    x = '0 1  2 3'
    y = '0 0 .5 1'
  [../]
[]

[BCs]
  [./fixx1]
    type = DirichletBC
    variable = disp_x
    boundary = 1
    value = 0.0
  [../]
  [./fixy1]
    type = DirichletBC
    variable = disp_y
    boundary = 1
    value = 0
  [../]
  [./fixz1]
    type = DirichletBC
    variable = disp_z
    boundary = 1
    value = 0
  [../]

  [./fixx2]
    type = DirichletBC
    variable = disp_x
    boundary = 2
    value = 0
  [../]
  [./fixz2]
    type = DirichletBC
    variable = disp_z
    boundary = 2
    value = 0
  [../]

  [./fixDummyHex_x]
    type = DirichletBC
    variable = disp_x
    boundary = 1000
    value = 0
  [../]

  [./fixDummyHex_y]
    type = DirichletBC
    variable = disp_y
    boundary = 1000
    value = 0
  [../]

  [./fixDummyHex_z]
    type = DirichletBC
    variable = disp_z
    boundary = 1000
    value = 0
  [../]
[]

[DiracKernels]
  [./pull]
    type = ConstantPointSource
    value = -25
    point = '0 -2 0'
    variable = disp_y
  [../]
[]

[AuxKernels]
  [./axial_stress]
    type = MaterialRealAux
    block = '1 2'
    property = axial_stress
    variable = axial_stress
  [../]
  [./e_over_l]
    type = MaterialRealAux
    block = '1 2'
    property = e_over_l
    variable = e_over_l
  [../]
  [./area1]
    type = ConstantAux
    block = 1
    variable = area
    value = 1.0
    execute_on = 'initial timestep_begin'
  [../]
  [./area2]
    type = ConstantAux
    block = 2
    variable = area
    value = 0.25
    execute_on = 'initial timestep_begin'
  [../]
[]

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

[Executioner]
  type = Transient

  solve_type = PJFNK

  petsc_options_iname = '-pc_type -ksp_gmres_restart'
  petsc_options_value = 'jacobi   101'

  nl_max_its = 15
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-10

  dt = 1
  num_steps = 1
  end_time = 1
[]

[Kernels]
  [./truss_x]
    type = StressDivergenceTensorsTruss
    block = '1 2'
    variable = disp_x
    displacements = 'disp_x disp_y disp_z'
    component = 0
    area = area
    save_in = react_x
  [../]
  [./truss_y]
    type = StressDivergenceTensorsTruss
    block = '1 2'
    variable = disp_y
    component = 1
    displacements = 'disp_x disp_y disp_z'
    area = area
    save_in = react_y
  [../]
  [./truss_z]
    type = StressDivergenceTensorsTruss
    block = '1 2'
    variable = disp_z
    component = 2
    displacements = 'disp_x disp_y disp_z'
    area = area
    save_in = react_z
  [../]
  [./TensorMechanics]
    block = 1000
    displacements = 'disp_x disp_y disp_z'
  [../]
#  [./hex_x]
#    type = StressDivergenceTensors
#    block = 1000
#    variable = disp_x
#    component = 0
#    displacements = 'disp_x disp_y disp_z'
#  [../]
#  [./hex_y]
#    type = StressDivergenceTensors
#    block = 1000
#    variable = disp_y
#    component = 1
#    displacements = 'disp_x disp_y disp_z'
#  [../]
#  [./hex_z]
#    type = StressDivergenceTensors
#    block = 1000
#    variable = disp_z
#    component = 2
#    displacements = 'disp_x disp_y disp_z'
#  [../]
[]

[Materials]
   [./elasticity_tensor]
    type = ComputeIsotropicElasticityTensor
    block = 1000
    youngs_modulus = 1e6
    poissons_ratio = 0
  [../]
  [./strain]
    type = ComputeSmallStrain
    block = 1000
    displacements = 'disp_x disp_y disp_z'
  [../]
  [./stress]
    type = ComputeLinearElasticStress
    block = 1000
  [../]
  [./linelast]
    type = LinearElasticTruss
    block = '1 2'
    displacements = 'disp_x disp_y disp_z'
    youngs_modulus = 1e6
  [../]
[]

[Outputs]
  exodus = true
[]

Child Objects

modules/tensor_mechanics/include/materials/PlasticTruss.h

modules/tensor_mechanics/include/materials/PlasticTruss.h

// This file is part of the MOOSE framework
// https://www.mooseframework.org
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "LinearElasticTruss.h"

class PlasticTruss;

template <>
InputParameters validParams<PlasticTruss>();

class PlasticTruss : public LinearElasticTruss
{
public:
  static InputParameters validParams();

  PlasticTruss(const InputParameters & parameters);

protected:
  virtual void computeQpStrain();
  virtual void computeQpStress();
  virtual void initQpStatefulProperties();

  virtual Real computeHardeningValue(Real scalar);
  virtual Real computeHardeningDerivative(Real scalar);

  //  yield stress and hardening property input
  Real _yield_stress;
  const Real _hardening_constant;
  const Function * _hardening_function;

  /// convergence tolerance
  Real _absolute_tolerance;
  Real _relative_tolerance;

  const MaterialProperty<Real> & _total_stretch_old;
  MaterialProperty<Real> & _plastic_strain;
  const MaterialProperty<Real> & _plastic_strain_old;
  const MaterialProperty<Real> & _stress_old;

  MaterialProperty<Real> & _hardening_variable;
  const MaterialProperty<Real> & _hardening_variable_old;

  /// maximum no. of iterations
  const unsigned int _max_its;
};

References

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