ProductsAbaqus/StandardAbaqus/Explicit
TypeModel data LevelModel
Required parameters
- TYPE
-
Set TYPE=DISPLACEMENT to define the evolution of damage as a function of the total
(for elastic materials in cohesive elements) or the plastic (for bulk
elastic-plastic materials) displacement after the initiation of damage.
Set TYPE=ENERGY to define the evolution of damage in terms of the energy
required for failure (fracture energy) after the initiation of damage.
Set
TYPE=HYSTERESIS ENERGY
to define the evolution of damage in terms of the inelastic hysteresis energy density
dissipated per stabilized cycle after the initiation of damage in a low-cycle fatigue
analysis.
Optional parameters
- DEGRADATION
-
Set DEGRADATION=MAXIMUM (default) to specify that the current damage evolution
mechanism will interact with other damage evolution mechanisms in a maximum
sense to determine the total damage from multiple mechanisms.
Set DEGRADATION=MULTIPLICATIVE to specify that the current damage evolution mechanism will
interact with other damage evolution mechanisms using the same value of the DEGRADATION parameter in a multiplicative manner to determine the total
damage from multiple mechanisms.
- DEPENDENCIES
-
Set this parameter equal to the number of field variables included in the
definition of damage evolution. If this parameter is omitted, it is assumed
that properties defining the evolution of damage are constant or depend only on
temperature.
See Material Data Definition for more information.
- FAILURE INDEX
-
This parameter can be used only in conjunction with the user-defined damage
initiation criterion.
Set this parameter equal to the corresponding failure mechanism specified in
the user-defined damage initiation criterion for enriched elements.
- MIXED MODE BEHAVIOR
-
This parameter is meaningful only when the
DAMAGE EVOLUTION option is used to define the evolution of damage for
materials associated with cohesive elements or for surface-based cohesive
behavior. If this parameter is omitted,
Abaqus
assumes that the damage evolution behavior is mode independent.
Set MIXED MODE BEHAVIOR=TABULAR to specify the fracture energy or displacement (total or
plastic) directly as a function of the shear-normal mode mix for cohesive
elements. This method must be used to specify the mixed-mode behavior for
cohesive elements when TYPE=DISPLACEMENT.
Set MIXED MODE BEHAVIOR=POWER LAW to specify the fracture energy as a function of the mode mix
by means of a power law mixed mode fracture criterion.
Set MIXED MODE BEHAVIOR=BK to specify the fracture energy as a function of the mode mix
by means of the Benzeggagh-Kenane mixed mode fracture criterion.
- MODE MIX RATIO
-
This parameter can be used only in conjunction with the MIXED MODE BEHAVIOR parameter. The specification of the damage evolution properties
(fracture energy or effective displacement) as a function of the mode mix
depends on the value of this parameter. See
Defining Damage Evolution Data as a Tabular Function of Mode Mix
or
Defining Damage Evolution Data as a Tabular Function of Mode Mix
for further details.
Set
MODE MIX RATIO=ENERGY
(default for surface-based cohesive behavior in Abaqus/Standard and Abaqus/Explicit and for materials associated with cohesive elements) to define the mode mix in
terms of a ratio of fracture energy in the different modes. The fracture energy is
computed based on the current state of deformation only, not the deformation history.
This option can be used when
MIXED MODE BEHAVIOR=POWER LAW
or BK.
Set
MODE MIX RATIO=ACCUMULATED ENERGY
(default for surface-based cohesive behavior in Abaqus/Explicit) to define the mode mix in terms of a ratio of fracture energy in the different
modes. The fracture energy is computed based on the energy accumulated over the entire
deformation history at an integration point. This option can be used when
MIXED MODE BEHAVIOR=POWER LAW
or BK. This option is not
available for surface-based cohesive behavior in Abaqus/Explicit.
Set MODE MIX RATIO=TRACTION to define the mode mix in terms of a ratio of traction
components.
- POWER
-
This parameter can be used only in conjunction with MIXED MODE BEHAVIOR=POWER LAW or MIXED MODE BEHAVIOR=BK.
Set this parameter equal to the exponent in the power law or the
Benzeggagh-Kenane criterion that defines the variation of fracture energy with
mode mix for cohesive elements.
- RATE DEPENDENT
-
This parameter can be used only in conjunction with the
DAMAGE INITIATION option used with CRITERION=MAXE, CRITERION=MAXS, CRITERION=QUADE, or CRITERION=QUADS for either cohesive elements with traction separation behavior
or cohesive contact in
Abaqus/Explicit.
Include this parameter to define the damage evolution criterion as a
function of the effective rate of separation.
-
REF ENERGY
-
This parameter can be used only in conjunction with
TYPE=HYSTERESIS ENERGY.
Set this parameter equal to a reference value of the accumulated inelastic hysteresis
energy density per cycle. The default is 1.0.
- SOFTENING
-
Set SOFTENING=LINEAR (default) to specify a linear softening stress-strain response
(after the initiation of damage) for linear elastic materials or a linear
evolution of the damage variable with deformation (after the initiation of
damage) for elastic-plastic materials.
Set SOFTENING=EXPONENTIAL to specify an exponential softening stress-strain response
(after the initiation of damage) for linear elastic materials or an exponential
evolution of the damage variable with deformation (after the initiation of
damage) for elastic-plastic materials.
Set SOFTENING=TABULAR to specify the evolution of the damage variable with
deformation (after the initiation of damage) in tabular form. SOFTENING=TABULAR can be used only in conjunction with TYPE=DISPLACEMENT.
Data lines
to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=LINEAR without the MIXED MODE BEHAVIOR and the RATE DEPENDENT parameters
- First line
-
Effective total or plastic displacement at failure, measured from the time
of damage initiation.
-
Temperature, if temperature dependent.
-
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 total or the plastic displacement at
failure as a function of temperature and other predefined field
variables.
Data lines to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=LINEAR, RATE DEPENDENT without the MIXED MODE BEHAVIOR parameter
- First line
-
Effective total or plastic displacement at failure, measured from the time
of damage initiation.
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
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 total or the plastic displacement at
failure as a function of temperature and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=ENERGY, SOFTENING=LINEAR without the MIXED MODE BEHAVIOR and the RATE DEPENDENT parameters
- First line
-
Fracture energy.
-
Temperature, if temperature dependent.
-
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 fracture energy as a function of
temperature and other predefined field
variables.
Data lines to specify damage evolution for TYPE=ENERGY, SOFTENING=LINEAR, RATE DEPENDENT without the MIXED MODE BEHAVIOR parameter
- First line
-
Fracture energy.
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
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 fracture energy as a function of
temperature and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=LINEAR, MIXED MODE BEHAVIOR=TABULAR and without the RATE DEPENDENT parameter
- First line
-
Total displacement at failure, measured from the time of damage initiation.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the total displacement at failure as a function
of mode mix, temperature, and other predefined field
variables.
Data lines to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=LINEAR, MIXED MODE BEHAVIOR=TABULAR, RATE DEPENDENT
- First
line
-
Total displacement at failure, measured from the time of damage initiation.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the total displacement at failure as a function
of mode mix, temperature, and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=ENERGY, SOFTENING=LINEAR, MIXED MODE BEHAVIOR=TABULAR and without the RATE DEPENDENT parameter
- First line
-
Fracture energy.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the fracture energy as a function of mode mix,
temperature, and other predefined field
variables.
Data lines to specify damage evolution for TYPE=ENERGY, SOFTENING=LINEAR, MIXED MODE BEHAVIOR=TABULAR, RATE DEPENDENT
- First
line
-
Fracture energy.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the fracture energy as a function of mode mix,
temperature, and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=EXPONENTIAL without the MIXED MODE BEHAVIOR and the RATE DEPENDENT parameters
- First line
-
Effective total or plastic displacement at failure, measured from the time
of damage initiation.
-
Exponential law parameter.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to five field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)
-
Sixth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the total or the plastic displacement at
failure and the exponential law parameter as a function of temperature and
other predefined field
variables.
Data lines to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=EXPONENTIAL, RATE DEPENDENT without the MIXED MODE BEHAVIOR parameter
- First line
-
Effective total or plastic displacement at failure, measured from the time
of damage initiation.
-
Exponential law parameter.
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to five field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)
-
Sixth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the total or the plastic displacement at
failure and the exponential law parameter as a function of temperature and
other predefined field
variables.
Data lines
to specify damage evolution for TYPE=ENERGY, SOFTENING=EXPONENTIAL without the MIXED MODE BEHAVIOR and the RATE DEPENDENT parameters
- First line
-
Fracture energy.
-
Temperature, if temperature dependent.
-
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 fracture energy as a function of
temperature and other predefined field
variables.
Data lines to specify damage evolution for TYPE=ENERGY, SOFTENING=EXPONENTIAL, RATE DEPENDENT without the MIXED MODE BEHAVIOR parameter
- First line
-
Fracture energy.
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
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 fracture energy as a function of
temperature and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=EXPONENTIAL, MIXED MODE BEHAVIOR=TABULAR and without the RATE DEPENDENT parameter
- First line
-
Total displacement at failure, measured from the time of damage initiation.
-
Exponential law parameter.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Third field variable.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than three)
-
Fourth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the total displacement at failure and the
exponential law parameter as a function of mode mix, temperature, and other
predefined field
variables.
Data lines to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=EXPONENTIAL, MIXED MODE BEHAVIOR=TABULAR, RATE DEPENDENT
- First
line
-
Total displacement at failure, measured from the time of damage initiation.
-
Exponential law parameter.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Third field variable.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than three)
-
Fourth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the total displacement at failure and the
exponential law parameter as a function of mode mix, temperature, and other
predefined field
variables.
Data lines
to specify damage evolution for TYPE=ENERGY, SOFTENING=EXPONENTIAL, MIXED MODE BEHAVIOR=TABULAR and without the RATE DEPENDENT parameter
- First line
-
Fracture energy.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the fracture energy as a function of mode mix,
temperature, and other predefined field
variables.
Data lines to specify damage evolution for TYPE=ENERGY, SOFTENING=EXPONENTIAL, MIXED MODE BEHAVIOR=TABULAR, RATE DEPENDENT
- First
line
-
Fracture energy.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the fracture energy as a function of mode mix,
temperature, and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=TABULAR without the MIXED MODE BEHAVIOR and the RATE DEPENDENT parameters
- First line
-
Damage variable.
-
Effective total or plastic displacement, measured from the time of damage
initiation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to five field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)
-
Sixth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the damage variable as a function of the total
or the plastic displacement, temperature, and other predefined field
variables.
Data lines to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=TABULAR, RATE DEPENDENT without the MIXED MODE BEHAVIOR parameter
- First line
-
Damage variable.
-
Effective total or plastic displacement, measured from the time of damage
initiation.
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to five field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)
-
Sixth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the damage variable as a function of the total
or the plastic displacement, temperature, and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=TABULAR, MIXED MODE BEHAVIOR=TABULAR and without the RATE DEPENDENT parameter
- First line
-
Damage variable.
-
Effective total displacement, measured from the time of damage initiation.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Third field variable.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than three)
-
Fourth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the damage variable as a function of the total
displacement, mode mix, temperature, and other predefined field
variables.
Data lines to specify damage evolution for TYPE=DISPLACEMENT, SOFTENING=TABULAR, MIXED MODE BEHAVIOR=TABULAR, RATE DEPENDENT
- First
line
-
Damage variable.
-
Effective total displacement, measured from the time of damage initiation.
-
Appropriate mode mix ratio.
-
Appropriate mode mix ratio (if relevant, for three-dimensional problems with
anisotropic shear behavior).
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Third field variable.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than three)
-
Fourth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the damage variable as a function of the total
displacement, mode mix, temperature, and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=ENERGY, SOFTENING=LINEAR or EXPONENTIAL, MIXED MODE BEHAVIOR=POWER LAW or BK and without the RATE DEPENDENT parameter
- First line
-
Normal mode fracture energy.
-
Shear mode fracture energy for failure in the first shear direction.
-
Shear mode fracture energy for failure in the second shear direction.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the fracture energy as a function of
temperature and other predefined field
variables.
Data lines to specify damage evolution for TYPE=ENERGY, SOFTENING=LINEAR or EXPONENTIAL, MIXED MODE BEHAVIOR=POWER LAW or BK, RATE DEPENDENT
- First
line
-
Normal mode fracture energy.
-
Shear mode fracture energy for failure in the first shear direction.
-
Shear mode fracture energy for failure in the second shear direction.
-
Effective rate of separation.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to four field variables.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
-
Fifth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the fracture energy as a function of
temperature and other predefined field
variables.
Data lines to specify damage evolution for
TYPE=ENERGY,
SOFTENING=LINEAR
for the damage model for unidirectional fiber-reinforced materials- First
line
-
Fracture energy of the lamina in the longitudinal tensile direction.
-
Fracture energy of the lamina in the longitudinal compressive direction.
-
Fracture energy of the lamina in the transverse tensile direction.
-
Fracture energy of the lamina in the transverse compressive direction.
-
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Third field variable.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than three)
-
Fourth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the dependence of fracture energies on
temperature and other predefined field
variables.
Data lines to specify damage evolution for
TYPE=ENERGY,
SOFTENING=EXPONENTIAL
for the damage model for bidirectional fabric-reinforced materials
- First line
-
Tensile fracture energy in local 1-direction,
.
Compressive fracture energy in local 1-direction,
.
Tensile fracture energy in local 2-direction,
.
Compressive fracture energy in local 2-direction,
.
Parameter for shear damage,
.
Maximum shear damage,
.
Temperature, if temperature dependent.
First field variable.
- Subsequent lines (only needed if the
DEPENDENCIES parameter has a value
greater than one)
-
Second field variable.
Etc., up to five field variables per line.
Repeat this set of data lines as often as necessary to define the
dependence of material constants on temperature and other predefined field
variables.
Data lines
to specify damage evolution for TYPE=HYSTERESIS ENERGY in a low-cycle fatigue analysis
- First line
Material constant,
. (Units of
.) Material constant,
. -
Temperature, if temperature dependent.
-
First field variable.
-
Second field variable.
-
Etc., up to five field variables per line.
- Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)
-
Sixth field variable.
-
Etc., up to eight field variables per line.
Repeat this set of data lines
as often as necessary to define the dependence of material constants on
temperature and other predefined field
variables.
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