- databasePath to NEML XML database.
C++ Type:FileName
Controllable:No
Description:Path to NEML XML database.
- modelModel name in NEML database.
C++ Type:std::string
Controllable:No
Description:Model name in NEML database.
NEML Stress
Use a constitutive model in the NEML library to compute stress
Stress Calculator Based on NEML Constitutive Models
This material model provides an interface to the constitutive models for structural materials provided by the Nuclear Engineering Material model Library (NEML) developed by Argonne National Laboratory. This is a general interface to all of the models provided by that library, which are documented in detail in the NEML documentation.
NEML permits the definition of complex material constitutive models, the details of which are defined in an XML file that is independent of the MOOSE input file. The required inputs for this model on the MOOSE side simply provide the location of the XML file, which contains a database of potentially multiple material models, and the name of the model within that database to be used. This model computes the stress, elasticity tensor, and material Jacobian.
Using this model requires that the NEML source code is present. NEML is provided as a submodule in BlackBear under the directory blackbear/contrib/neml. The up-to-date version of the NEML submodule is obtained using:
git submodule init
git submodule update
in the blackbear directory. NEML is compiled using the MOOSE build system, so no separate compilation step is required to build the library.
Example Input Syntax
[Materials<<<{"href": "../../syntax/Materials/index.html"}>>>]
[stress]
type = NEMLStress<<<{"description": "Use a constitutive model in the NEML library to compute stress", "href": "NEMLStress.html"}>>>
model<<<{"description": "Model name in NEML database."}>>> = simple_example
database<<<{"description": "Path to NEML XML database."}>>> = 'examples.xml'
[]
[]The standard usage of NEMLStress is shown in this input file, where all material properties are provided in the xml file as shown:
<materials>
<simple_example type="SmallStrainElasticity">
<elastic type="IsotropicLinearElasticModel">
<m1_type>youngs</m1_type>
<m1>100000</m1>
<m2_type>poissons</m2_type>
<m2>0.30</m2>
</elastic>
<alpha>1.0e-4</alpha>
</simple_example>
A NEML xml file starts with the xml root <materials> and with in this root, multiple material models are defined within separate xml elements. This example xml file contains three material models, i.e. simple_elastic, variable_example, complex_example. The model keyword is used to select a particular model from the NEML xml file. The model name in the xml file is given in the xml tag that that begin and end the xml element. The xml tag containing the material model also contains the model type.
Example Input Syntax with Parameter Substitution
[Materials<<<{"href": "../../syntax/Materials/index.html"}>>>]
[stress]
type = NEMLStress<<<{"description": "Use a constitutive model in the NEML library to compute stress", "href": "NEMLStress.html"}>>>
database<<<{"description": "Path to NEML XML database."}>>> = 'examples.xml'
model<<<{"description": "Model name in NEML database."}>>> = variable_example
neml_variable_iname<<<{"description": "Names of NEML XML name/value pairs"}>>> = 'PoissonsVar YoungsVar'
neml_variable_value<<<{"description": "Corresponding NEML XML variable values"}>>> = '0.3 100000'
[]
[]Alternatively, this input file uses optional parameters that allow some of the NEML model parameters that would ordinarily be defined in the xml file to be defined in the MOOSE input file. This option is provided to allow selected values to be varied for sampling using the stochastic_tools module. The numerical values that are ordinarily used in the NEML xml file must be replaced by unique string identifiers enclosed in {}, which are then referenced in the neml_variable_iname parameter in the MOOSE input file. In this example, these identifiers are PoissonsVar and YoungsVar.
<variable_example type="SmallStrainElasticity">
<elastic type="IsotropicLinearElasticModel">
<m1_type>youngs</m1_type>
<m1>{YoungsVar}</m1>
<m2_type>poissons</m2_type>
<m2>{PoissonsVar}</m2>
</elastic>
<alpha>1.0e-4</alpha>
</variable_example>
The numerical values that get substituted for the identifiers defined in neml_variable_iname are prescribed using the neml_variable_value0 through neml_variable_value7 parameters. The numbers at the end of these parameters indicate the position in the neml_variable_iname vector of the identifier to be substituted. Up to 8 parameters are allowed to be defined in this way. These are specifed using separate parameters, rather than in a vector, to allow for their values to be sampled using stochastic_tools which does not currently support modifying parameter vector entries.
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
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
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
- debugFalsePrint history and strain state at the current quadrature point when a NEML stress update fails.
Default:False
C++ Type:bool
Controllable:No
Description:Print history and strain state at the current quadrature point when a NEML stress update fails.
- 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.
- neml_variable_inameNames of NEML XML name/value pairs
C++ Type:std::vector<std::string>
Controllable:No
Description:Names of NEML XML name/value pairs
- neml_variable_valueCorresponding NEML XML variable values
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Corresponding NEML XML variable values
- target_incrementL2 norm of the inelastic strain increment to target by adjusting the timestep
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:L2 norm of the inelastic strain increment to target by adjusting the timestep
- temperatureCoupled temperature
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Coupled temperature
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
- 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.
- 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.