ProductsAbaqus/StandardAbaqus/Explicit TypeModel data
LevelModel
Optional parameters
- DEFINITION
-
Set DEFINITION=WLF (default) to define the shift function by the
Williams-Landel-Ferry approximation.
Set DEFINITION=ARRHENIUS to define the shift function by the Arrhenius approximation.
Set DEFINITION=USER to define the shift function in user subroutines. In
Abaqus/Standard
analyses define the shift function in user subroutine
UTRS for the linear viscoelastic model (see
Time Domain Viscoelasticity)
or in user subroutine
UTRSNETWORK for the nonlinear viscoelastic model defined using the
parallel rheological framework (see
Parallel Rheological Framework).
In
Abaqus/Explicit
analyses define the shift function in user subroutine
VUTRS for the linear viscoelastic model.
Set DEFINITION=TNM to define the shift and response functions for the
Tool-Narayanaswamy-Moynihan model.
Set
DEFINITION=TABULAR
to define the shift function in tabular form.
-
DEPENDENCIES
-
This parameter is relevant only for
DEFINITION=TABULAR.
Set this parameter equal to the number of field variables included in the
specification of the shift function.
If this parameter is omitted, it is assumed that the shift function is constant or
depends only on temperature. For more information, see Material Data Definition.
- PROPERTIES
-
This parameter applies only to
Abaqus/Explicit
analyses and to
Abaqus/Standard
analyses if user subroutine
UTRSNETWORK is used to define the shift function.
Set this parameter equal to the number of properties being entered. The
properties are available for use in user subroutines
VUTRS or
UTRSNETWORK.
Data line to define the
shift function by the Williams-Landel-Ferry approximation
- First (and only) line
-
Reference temperature, .
-
Calibration constant, .
-
Calibration constant, .
Data line to define the shift function by the Arrhenius approximation by specifying
the reference temperature and the activation energy
- First (and only) line
-
-
Reference temperature, .
-
Activation energy, .
In addition, you need to specify the universal gas constant and absolute zero using the PHYSICAL CONSTANTS option.
Data line to define the shift function by the Arrhenius approximation by
specifying the reference temperature and the ratio of the activation energy to the universal
gas constant
- First (and only) line
-
Reference temperature,
.
Blank space.
Ratio of the activation energy to the universal gas constant,
.
In addition, you need to specify absolute zero using the PHYSICAL CONSTANTS option.
Data lines to define
material properties for a user-defined shift function (DEFINITION=USER)- No data
lines are needed if the PROPERTIES parameter is omitted or set to 0. Otherwise, first
line
-
Enter the material properties, eight per line.
Repeat this data line as
often as necessary to define all material
properties.
Data lines to define
the shift and response functions for the TNM model
- First
line
- Reference
temperature, .
- Activation energy, .
- Material parameter, .
- Initial fictive temperature, .
- Number of terms in the response
function.
- Second line
- Coefficient, ,
in the first term of the response function.
- Relaxation
time, ,
in the first term of the response function.
In addition, you need to specify the universal gas constant and absolute
zero using the
PHYSICAL CONSTANTS option.
Repeat this data line
as often as necessary to define the second, third, etc. terms of the response
function. There is no restriction on the number of terms in the response
function.
Data lines to define the shift function in tabular form
- First line
-
- Logarithm to base 10 of the shift function,
.
- Temperature,
.
- First field variable.
- Second field variable.
- Etc., up to six field variables.
- Subsequent lines (only needed if the
DEPENDENCIES parameter has a value
greater than six)
-
- Seventh field variable.
- Etc., up to eight field variables per line.
Repeat this set of data lines as often as necessary to define the
logarithm of the shift function as a function of temperature and other predefined
field variables.
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