Model keywords; keyword@Author keyword@Bounds keyword@Coef keyword@ConstantMaterialProperty keyword@DSL keyword@Date keyword@Description keyword@Domain keyword@Domains keyword@ExternalStateVariable keyword@Function keyword@Import keyword@Includes keyword@Input keyword@LocalParameter keyword@Material keyword@MaterialLaw keyword@MaterialProperty keyword@Model keyword@Output keyword@Parameter keyword@Parser keyword@PhysicalBounds keyword@StateVariable keyword@StaticVar keyword@StaticVariable keyword@UnitSystem keyword@UseQt keyword; keywordThe keyword ; is not documented yet
@Author keywordThe @Author keyword is used to give the name of the person who wrote the mfront file.
All the following words are appended to the author’s name up to a final semi-colon.
Note: The name of the person who formulated the material property, behaviour or model shall be given in the description section (see the @Description keyword).
@Author Éric Brunon;@Bounds keywordThe @Bounds keyword let the user define the domain of validity of the law.
The @Bounds keyword is followed by a variable name, the keyword in and an interval. The interval may contain the infinity, represented by the ’*’ character.
What happens if a variable if found to be out of its bounds depends on the interface used. Most interfaces let the user choose one of three following policies:
None, which means that nothing is done.Warning, which means that a message is displayed, but computations are not stopped.Strict, which means that computations are stopped with an error message.@Bounds T in [293.15:873.15];@Coef keywordThe @Coef keyword is a deprecated synonymous of @MaterialProperty.
@ConstantMaterialProperty keywordThe @ConstantMaterialPropery let the user define a specific kind of input to a model which is meant to be constant and uniform during the computations. This allows the interfaces to optimize the generated code. This keyword is followed by the names of the material properties. Those names must be valid C++ identifiers.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
It is recommended to associate to a constant material property a glossary or an entry name through the methods setGlossaryName or setEntryName respectively.
@ConstantMaterialProperty E;
E.setEntryName("EnergyReleasedByFission");@DSL keywordThe @DSL keyword specify the domain specific language (dsl) used.
The list of available dsl’s is returned by the --list-dsl option of mfront:
$ mfront --list-dslAs the time of writting this notice, the following dsl’s are available:
DefaultDSL: this parser is the most generic one as it does not make any restriction on the behaviour or the integration method that may be used.DefaultCZMDSL: this parser is the most generic one as it does not make any restriction on the behaviour or the integration method that may be used.DefaultFiniteStrainDSL: this parser is the most generic one as it does not make any restriction on the behaviour or the integration method that may be used.Implicit: this parser provides a generic integrator based on an implicit scheme. The elastic strain is automatically defined as a state variableImplicitII: this parser provides a generic integrator based on a theta method. Unlike Implicit, the elastic strain is not automatically defined as a state variable.ImplicitFiniteStrain: this parser provides a generic integrator based on a theta method..IsotropicMisesCreep: this parser is used for standard creep behaviours of the form \(\dot{p}=f(s)\) where \(p\) is the equivalent creep strain and \(s\) the equivalent mises stress.IsotropicPlasticMisesFlow: this parser is used for standard plastics behaviours with yield surface of the form \(f(s,p)=0\) where \(p\) is the equivalent creep strain and \(s\) the equivalent mises stress.IsotropicStrainHardeningMisesCreep: this parser is used for standard strain hardening creep behaviours of the form \(\dot{p}=f(s,p)\) where \(p\) is the equivalent creep strain and \(s\) the equivalent mises stress.MaterialLaw: this parser is used to define material properties.Model: this parser is used to define simple material models.MultipleIsotropicMisesFlows: this parser is used to define behaviours combining several isotropic flows. Supported flow type are ‘Creep’ (\(\dot{p}=f(s)\)) ‘StrainHardeningCreep’ (\(\dot{p}=f(s,p)\)) and ‘Plasticity’ (\(f(p,s)=0\)) where \(p\) is the equivalent plastic strain and \(s\) the equivalent mises stress.RungeKutta: this parser provides a generic integrator based on one of the many Runge-Kutta algorithm.A DSL’ behaviour may be changed using options defined either in the MFront file using a JSON-like syntax or as a command line argument.
The options related to a specific DSL can be retrieved using the --list-dsl-options command line argument, as follows:
$ mfront --list-dsl-options=Model
- parameters_as_static_variables: boolean stating if the parameter shall be treated as static variables.
- build_identifier : string specifying a build identifier. This option shall only be specified on the command line.DSL options in the MFront fileOptions can be passed to a DSL as follows:
@DSL Default{
parameters_as_static_variables : true
};DSL options on the command line:MFront have various command line arguments to define options passed to DSLs:
--dsl-option, which allows to define options passed to domain specific languages.--behaviour-dsl-option, which allows to define options passed to domain specific languages related to behaviours.--material-property-dsl-option, which allows to define options passed to domain specific languages related to material properties.--model-dsl-option, which allows to define options passed to domain specific languages related to models.For example, the --dsl-option can be used as follows:
$ mfront --obuild --interface=cyrano --dsl-option=build_identifier:\"Cyrano-3.2\" Elasticity.mfrontThis example illustrates that special care must be taken when defining an option expecting a string value.
The following options are available for all DSLs:
build_identifier (string), which must be associated to a string value. However, the build_identifier is not meant to be directly specified in the MFront source file. It shall rather be defined on the command line.parameters_as_static_variables (boolean), which states if parameters shall be treated as static variables.parameters_initialization_from_file (boolean), which states if parameters can be modified from a external state file. This feature is only implemented by a few interfaces and is enabled by default.default_out_of_bounds_policy (string), which selects the default out of bounds policy. Allowed values ar None (the default), Warning or Strict.out_of_bounds_policy_runtime_modification (boolean), which states if the out of bounds policy can be changed at runtime. By default, this option is true.automatic_declaration_of_the_temperature_as_first_external_state_variable (boolean), which states if the temperature shall be automatically declared as an external state variable.overriding_parameters, which allows to specify overriding parameters. This parameters must be a map associating variables names and default values of the overriding parameters.@DSL Implicit;@Date keywordThe @Date keyword allows the user to precise when the mfront file was written.
All the following words are appended to the date up to a final semi-colon.
@Date 2008-11-17;@Description keywordThe @Description describes the material property, behaviour or model which is implemented in a mfront file.
This keyword is followed by a block containing all the relevant piece of information including:
@Description
{
Corrélation établie sur la nuance V-4Cr-4Ti.
Propriétés extraites du document :
Propriétés et comportement mécanique d alliages
de Vanadium avant, après et sous irradiation
Marion Le Flem, Jean-Luc Bechade, Annick Bougault,
Aurore Michaux, Lionel Gosmain, Jean-Louis Seran
DMN/SRMA/LA2M/NT/2008-2967/A
}@Domain keywordThe @Domain let the user define the default domain on which a model shall be applied. This keyword is followed by the name of the domain.
This keyword is deprecated as domains shall be explicitely specified by specialisation.
@Domain "Fuel";@Domains keywordThe @Domains let the user define the default domains on which a model shall be applied. This keyword is followed by an array of strings.
This keyword is deprecated as domains shall be explicitely specified by specialisation.
@Domains {"MATRIX","CLADDING"};@ExternalStateVariable keywordThe ExternalStateVariable keyword introduces one or several new external state variables. It is followed by a type name and the name(s) of the variable(s) declared, separated by commas.
The external state variables names must be valid C++ identifiers.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
One may declare an array of external state variables by specifying the array size after the external state variable name.
It is recommended to associate to a external state variable a glossary or an entry name through the methods setGlossaryName or setEntryName respectively.
// scalar external state variable
@ExternalStateVariable strain s;@Function keywordThe @Function keyword defines a computational part of the model. This keyword is followed by a string defining the name of this part of the computation.
@Function compute
{
const real coef1 = 8.e-3;
const real coef2 = 4.e-2;
const real p_ = 0.5*(p+p_1);
s = s_1 + coef1*exp(coef2-p_)*(Bu-Bu_1);
} // end of function compute@Import keywordThe @Import keyword allows the inclusion of one or several (external) mfront files. This keyword is followed by a string or an array of strings. Each string stands for a mfront file name that is meant to be imported.
This instruction interrupts the treatment of the current file and starts the sequential treatment of each file to be imported.
Files to be imported are searched, in that order:
--search-path or the --include (-I) mfront’ command line options.MFRONT_INCLUDE_PATH environment variable.@Import "SlidingSystemsCC.mfront";@Includes keywordThe @Includes introduces a block were the user may define some preprocessor directives, typically #include directives (hence the name).
@Includes{
#include<fstream>
}@Input keywordThe @Input keyword specifies one or several inputs of a material law. This keyword is followed by the names of the inputs, separated by commas.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
The depth of a variable is the number of preceedings values of this variable needed to perform the computations. A depth of \(0\) means that only the value at the end of the time step is required. A depth of \(1\) means that we need the value of the variable a the end of the time step and the value at the beginning of the time step.
The depth of a variable is set using the setDepth method.
If p is the variable of interest, p is its value at the end of the time step, p_1 is the value at the beginning of the time step.
It is recommended to associate to an input a glossary or an entry name through the methods setGlossaryName or setEntryName respectively.
@Input T,p;
T.setGlossaryName("Temperature");
p.setGlossaryName("Porosity");
// we need the value at the end of the time step and the value at the
// beginning at the time step
p.setGlossaryName("Porosity");@LocalParameter keywordThe @LocalParameter keyword let the user defines specialisation parameters. This keyword is followed by the type and the names of the parameters, separated by commas. The names of the variables must be valid C++ identifiers.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
The user may attribute a default value to a local parameter through the setDefaultValue method.
@LocalParameter real a;
a.setDefaultValue(1.23);@Material keywordThe @Material keyword let the user specify which material is treated by the current file. This keyword is followed by the name of the material.
This name must be a valid C++ identifier. The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
@Material UO2;@MaterialLaw keywordThe @MaterialLaw keyword imports the definition of a material law defined in a mfront file and compiles, as part of the current library, an function using the mfront interface. This function is available in every standard code blocks.
The @MaterialLaw keyword is followed by a string or an array of string identifying mfront files.
Files to be imported are searched, in that order:
--search-path or the --include (-I) mfront’ command line options.MFRONT_INCLUDE_PATH environment variable.The mfront interface has been created to avoid names conflict.
For internal reasons, mfront reports the creation of an auxiliary library which is of no use.
@MaterialLaw "UO2_YoungModulus.mfront";@MaterialProperty keywordThe @MaterialProperty keyword let the user define one or several material properties. This keyword is followed by the type of the material property and a list of material properties names separated by commas.
The material properties names must be valid C++ identifiers.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
One may declare an array of material properties by specifying the array size after the material property name.
It is recommended to associate to a material property a glossary or an entry name through the methods setGlossaryName or setEntryName respectively.
// scalar material property
@MaterialProperty stress young;
young.setGlossaryName("YoungModulus");@Model keywordThe @Model defines the name of the model. The name must be a valid C++ class name.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
@Model SolidSwelling;@Output keywordThe @Output keyword specifies one or several outputs of a material law. This keyword is followed by the names of the outputs, separated by commas.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
The depth of a variable is the number of preceedings values of this variable needed to perform the computations. A depth of \(0\) means that only the value at the end of the time step is required. A depth of \(1\) means that we need the value of the variable a the end of the time step and the value at the beginning of the time step.
The depth of a variable is set using the setDepth method.
If p is the variable of interest, p is its value at the end of the time step, p_1 is the value at the beginning of the time step.
It is recommended to associate to an output a glossary or an entry name through the methods setGlossaryName or setEntryName respectively.
@Output T,p;
T.setGlossaryName("Temperature");
p.setGlossaryName("Porosity");@Parameter keywordThe @Parameter keyword declares a new parameter or a list of new parameters. Optionally, the default value of the declared parameters may also be given following various C++ standard assignment syntaxes.
The default value of a parameter can also be declared after its declaration using the setDefaultValue method.
@Parameter R0 = 500;
@Parameter Q1{1000000000},b1{0.000001};
@Parameter Q2(0),b2(0);
@Parameter fc;
fc.setDefaultValue(1.e-2);@Parser keywordThe @Paser keyword is a deprecated synonymous of @DSL.
@PhysicalBounds keywordThe @PhysicalBounds keyword let the use define the physical domain of a variable.
The @PhysicalBounds keyword is followed by a variable name, the keyword in and an interval. The interval may contain the infinity, represented by the ’*’ character.
In implicit schemes, if physical bounds are set on a integration variable, this variable is bounded to satisfy them during the internal iterations.
If a variable is found to be out of its physical bounds, the computations are stopped. The tests are performed at different stages of the integration depending on the nature of the variable.
// a temperature (in Kelvin) can't be negative
@PhysicalBounds T in [0:*[;@StateVariable keywordThe StateVariable keyword introduces one or several new state variables. It is followed by a type name and the name(s) of the variable(s) declared, separated by commas.
The state variables names must be valid C++ identifiers.
The following characters are legal as the first character of an identifier, or any subsequent character:
_ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The following characters are legal as any character in an identifier except the first:
0 1 2 3 4 5 6 7 8 9
One may declare an array of state variables by specifying the array size after the state variable name.
It is recommended to associate to a state variable a glossary or an entry name through the methods setGlossaryName or setEntryName respectively.
// scalar state variable
@StateVariables strain p;
// symmetric tensors state variable
@StateVariables StrainStensor evp,evp2;@StaticVar keywordThe @StaticVar keyword is a deprecated synonymous of @StaticVariable.
@StaticVariable keywordThe @StaticVariable keyword let the user define a constant value. Unlike parameters (see the @Parameter keyword), static variables’ values can’t be changed after compilation.
This keyword must be followed by the type of the constant, its name, an equal sign and its value.
@StaticVariable real A = 1.234e56;@UnitSystem keywordThe @UnitSystem keyword declares that the state variables, external state variables an parameters are expressed in a given unit system. In the current version of MFront, the only supported unit system is the international system of units, denoted SI.
One advantage of declaring an unit system is that physical bounds of variables associated with a glossary entry can automatically be declared by MFront.
For instance the declaration of the physical bounds for the temperature and the porosity is automatic if the SI unit system is used.
@UnitSystem SI;@UseQt keywordThe UseQt keyword (use quantities) specify if the behaviour compilation should perform compile-time units checks. It is followed by a boolean.
This feature is still experimental and is disabled in most cases.
@UseQt true;