- displacementsThe displacements appropriate for the simulation geometry and coordinate system
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:The displacements appropriate for the simulation geometry and coordinate system
Compute Plane Small Strain
Compute a small strain under generalized plane strain assumptions where the out of plane strain is generally nonzero.
Description
The material ADComputePlaneSmallStrain calculates the small total strain for 2D plane strain problems. It can be used for classical plane strain or plane stress problems, or in Generalized Plane Strain simulations.
Out of Plane Strain
In the classical plane strain problem, it is assumed that the front and back surfaces of the body are constrained in the out-of-plane direction, and that the displacements in that direction on those surfaces are zero. As a result, the strain and deformation gradient components in the out-of-plane direction are held constant at zero: (1) is the strain tensor diagonal component for the direction of the out-of-plane strain.
Plane Stress and Generalized Plane Strain
In the cases of the plane stress and generalized plane strain assumptions, the component of strain and the deformation gradient in the out-of-plane direction is non-zero. To solve for this out-of-plane strain, we use the out-of-plane strain variable as the strain tensor component (2) where is the strain tensor diagonal component for the direction of the out-of-plane strain and is a prescribed out-of-plane strain value: this strain value can be given either as a scalar variable or a nonlinear field variable. The Generalized Plane Strain problems use scalar variables. Multiple scalar variables can be provided such that one strain calculator is needed for multiple generalized plane strain models on different subdomains.
For the case of plane stress, the ADWeakPlaneStress kernel is used to integrate the out-of-plane component of the stress over the area of each element, and assemble that integral to the residual of the out-of-plane strain field variable. This results in a weak enforcement of the condition that the out-of-plane stress is zero, which allows for re-use of the same constitutive models for models of all dimensionality.
Strain and Deformation Gradient Formulation
The definition of a small total linearized strain is (3) The values of each of the strain tensor components depends on the direction selected by the user as the out-of-plane direction.
-Direction of Out-of-Plane Strain (Default)
The default out-of-plane direction is along the -axis. For this direction the strain tensor, Eq. (3), is given as (4) where is defined in Eq. (2). As in the classical presentation of the strain tensor in plane strain problems, the components of the strain tensor associated with the -direction are zero; these zero components indicate no coupling between the in-plane and the out-of-plane strains.
-Direction of Out-of-Plane Strain
If the user selects the out-of-plane direction as along the -direction, the strain tensor from Eq. (3) is given as (5) so that the off-diagonal components of the strain tensor associated with the -direction are zeros.
-Direction of Out-of-Plane Strain
If the user selects the out-of-plane direction as along the -direction, the strain tensor from Eq. (3) is given as (6) so that the off-diagonal components of the strain tensor associated with the -direction are zeros.
Volumetric Locking Correction for Strain Tensor
If selected by the user, the strain tensor is conditioned with a formulation to mitigate volumetric locking of the elements. The volumetric locking correction is applied to the total strain (7) where is the volumetric strain and is the Rank-2 identity tensor. For more details about the theory behind Eq. (7) see the Volumetric Locking Correction documentation.
Example Input Files
Plane Stress
The solid mechanics QuasiStatic Physics can be used to create the ADComputePlaneSmallStrain class by setting planar_formulation = WEAK_PLANE_STRESS and strain = SMALL in the QuasiStatic Physics block.
[Physics]
[SolidMechanics]
[QuasiStatic]
[plane_stress]
planar_formulation = WEAK_PLANE_STRESS
strain = SMALL
generate_output = 'stress_xx stress_xy stress_yy stress_zz strain_xx strain_xy strain_yy'
eigenstrain_names = eigenstrain
[]
[]
[]
[]
Note that for plane stress analysis, the out_of_plane_strain parameter must be defined, and is the name of the out-of-plane strain field variable.
[./strain_zz]
[../]
In the case of this example, out_of_plane_strain is defined in the GlobalParams block.
Generalized Plane Strain
The use of this plane strain class for Generalized Plane Strain simulations uses the scalar out-of-plane strains. The solid mechanics QuasiStatic Physics is used to create the ADComputePlaneSmallStrain class with the planar_formulation = GENERALIZED_PLANE_STRAIN and strain = SMALL settings.
[Physics]
[SolidMechanics]
[QuasiStatic]
[all]
strain = SMALL
add_variables = true
displacements = 'disp_x disp_y'
generate_output = 'stress_xx stress_xy stress_yy stress_zz strain_xx strain_xy strain_yy strain_zz'
planar_formulation = GENERALIZED_PLANE_STRAIN
eigenstrain_names = eigenstrain
scalar_out_of_plane_strain = scalar_strain_zz
temperature = temp
save_in = 'saved_x saved_y'
[]
[]
[]
[]
Note that the argument for the scalar_out_of_plane_strain parameter is the name of the scalar strain variable
[Variables]
[scalar_strain_zz]
order = FIRST
family = SCALAR
[]
[]
-Direction of Out-of-Plane Strain
This plane strain class is used to model plane strain with an out-of-plane strain in directions other than in the -direction. As an example, the solid mechanics QuasiStatic Physics can be used to create the ComputePlaneFiniteStrain class for a -direction out-of-plane strain with the planar_formulation = PLANE_STRAIN and the out_of_plane_direction = y settings.
[./plane_strain]
block = 1
strain = SMALL
out_of_plane_direction = y
planar_formulation = PLANE_STRAIN
eigenstrain_names = 'eigenstrain'
generate_output = 'stress_xx stress_xz stress_yy stress_zz strain_xx strain_xz strain_yy strain_zz'
[../]
Input 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
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
Controllable:No
Description:Optional material property holding a global strain tensor applied to the mesh as a whole
- out_of_plane_directionzThe direction of the out-of-plane strain.
Default:z
C++ Type:MooseEnum
Unit:(no unit assumed)
Controllable:No
Description:The direction of the out-of-plane strain.
- out_of_plane_strainNonlinear variable for plane stress condition
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Nonlinear variable for plane stress condition
- 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
Unit:(no unit assumed)
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.
- scalar_out_of_plane_strainScalar variable for generalized plane strain
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Scalar variable for generalized plane strain
- subblock_index_providerSubblockIndexProvider user object name
C++ Type:UserObjectName
Unit:(no unit assumed)
Controllable:No
Description:SubblockIndexProvider user object name
- 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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
Controllable:No
Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object