Compute Incremental Small Strain

Compute a strain increment and rotation increment for small strains.

Description

The material ComputeIncrementalSmallStrain is designed for linear elasticity problems formulated within an incremental framework. As with ComputeSmallStrain, this material is useful for verifying material models with hand calculations because of the simplified strain calculations. As in the small strain material, the incremental small strain class assumes the gradient of displacement with respect to position is much smaller than unity, and the squared displacement gradient term is neglected in the small strain definition to give: As the class name suggests, ComputeIncrementalSmallStrain is an incremental formulation. The stress increment is calculated from the current strain increment at each time step. In this class, the rotation tensor is defined to be the rank-2 Identity tensor: no rotations are allowed in the model. Stateful properties, including strain_old and stress_old, are stored. This incremental small strain material is useful as a component of verifying more complex finite incremental strain-stress calculations.

Example Input File Syntax

The incremental small strain calculator can be activated in the input file through the use of the Solid Mechanics Physics, as shown below.

[Physics]
  [SolidMechanics]
    [QuasiStatic]
      [./all]
        strain = SMALL
        incremental = true
        add_variables = true
        eigenstrain_names = eigenstrain
        generate_output = 'strain_xx strain_yy strain_zz'
      [../]
    [../]
  [../]
[]
(modules/solid_mechanics/test/tests/thermal_expansion/constant_expansion_coeff.i)
commentnote:Use of the Solid Mechanics QuasiStatic Physics Recommended

The Solid Mechanics Physics is designed to automatically determine and set the strain and stress divergence parameters correctly for the selected strain formulation. We recommend that users employ the Solid Mechanics Physics whenever possible to ensure consistency between the test function gradients and the strain formulation selected.

Although not recommended, it is possible to directly use the ComputeIncrementalSmallStrain material in the input file.

[./small_strain]
  type = ComputeIncrementalSmallStrain
  eigenstrain_names = 'eigenstrain1 eigenstrain2'
[../]
(modules/solid_mechanics/test/tests/thermal_expansion/multiple_thermal_eigenstrains.i)

Input Parameters

  • displacementsThe displacements appropriate for the simulation geometry and coordinate system

    C++ Type:std::vector<VariableName>

    Controllable:No

    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

    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.

  • eigenstrain_namesList of eigenstrains to be applied in this strain calculation

    C++ Type:std::vector<MaterialPropertyName>

    Controllable:No

    Description:List of eigenstrains to be applied in this strain calculation

  • global_strainOptional material property holding a global strain tensor applied to the mesh as a whole

    C++ Type:MaterialPropertyName

    Controllable:No

    Description:Optional material property holding a global strain tensor applied to the mesh as a whole

  • 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.

  • 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.

  • volumetric_locking_correctionFalseFlag to correct volumetric locking

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Flag to correct volumetric locking

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

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

Input Files

Child Objects