ADComputeSmallStrain

Compute a small strain.

Description

The material ADComputeSmallStrain is designed for linear elasticity problems, which calculates the small, total strain. This material is useful for verifying material models with hand calculations because of the simplified strain calculations. This material supplies material properties with all derivatives required to form an exact Jacobian.

Linearized small strain theory assumes that 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:

For more details on the linearized small strain assumption and derivation, see a Continuum Mechanics text such as Malvern (1969) or Bower (2009), specifically Chapter 2.

Total strain theories are path independent: in MOOSE, path independence means that the total strain, from the beginning of the entire simulation, is used to calculate stress and other material properties. Incremental theories, on the other hand, use the increment of strain at timestep to calculate stress. Because the total strain formulation ADComputeSmallStrain is path independent, no old values of strain or stress from the previous timestep are stored in MOOSE. For a comparison of total strain vs incremental strain theories with experimental data, see Shammamy and Sidebottom (1967).

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.

  • 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

References

  1. A. F. Bower. Applied Mechanics of Solids. CRC press, 2009.[BibTeX]
  2. Lawrence E Malvern. Introduction to the Mechanics of a Continuous Medium. Prentice-Hall, 1969.[BibTeX]
  3. MR Shammamy and OM Sidebottom. Incremental versus total-strain theories for proportionate and nonproportionate loading of torsion-tension members. Experimental Mechanics, 7(12):497–505, 1967.[BibTeX]