*DAMPING

Specify material damping.

Warning: The use of stiffness proportional material damping or band-limited damping in Abaqus/Explicit may reduce the stable time increment dramatically and can lead to longer analysis times. See Material Damping.

This option is used to provide material damping for mode-based analyses and direct-integration dynamic analyses in Abaqus/Standard and for explicit dynamic analysis in Abaqus/Explicit.

Damping is defined in a material data block except in the case of elements defined with the BEAM GENERAL SECTION option, the SHELL GENERAL SECTION option, the ROTARY INERTIA option, the MASS option, or the SUBSTRUCTURE PROPERTY option. For the BEAM GENERAL SECTION, the SHELL GENERAL SECTION, and the SUBSTRUCTURE PROPERTY options the DAMPING option must be used in conjunction with the property references. For the MASS and the ROTARY INERTIA options damping must be specified using either the ALPHA or the COMPOSITE parameter associated with these options. Damping can also come from damper elements like connectors and dashpots, and it may also be defined as step data using the GLOBAL DAMPING and MODAL DAMPING options.

You must use multiple DAMPING options if you want to define temperature dependence (and/or field dependence in Abaqus/Explicit) for more than one material damping coefficient.

This option is ignored in mode-based procedures that use Lanczos or subspace iteration eigenvalue extraction that does not use the SIM architecture (FREQUENCY, EIGENSOLVER=SUBSPACE, SIM=NO).

This page discusses:

Optional parameters

ALPHA

Set this parameter equal to the αR factor to create Rayleigh mass proportional damping in the following procedures:

The default is ALPHA=0. (Units of T−1.)

In Abaqus/Standard set ALPHA=TABULAR to specify that the mass proportional viscous damping is dependent on temperature.

In Abaqus/Explicit set ALPHA=TABULAR to specify that the mass proportional damping is dependent on temperature and/or field variables.

BAND LIMITED

This parameter applies only to Abaqus/Explicit analyses.

Set this parameter equal to the damping ratio, η d , used in the band-limited damping. The default is BAND LIMITED=0.

Set BAND LIMITED=TABULAR to specify that the damping ratio in band-limited damping is dependent on temperature and/or field variables.

BETA

Set this parameter equal to the βR factor to create Rayleigh stiffness proportional damping in the following procedures:

The default is BETA=0. (Units of T.)

In Abaqus/Standard set BETA=TABULAR to specify that the stiffness proportional viscous damping is dependent on temperature.

In Abaqus/Explicit set BETA=TABULAR to specify that the stiffness proportional damping is dependent on temperature and/or field dependent variables.

COMPOSITE

This parameter applies only to Abaqus/Standard analyses.

Set this parameter equal to the fraction of critical damping to be used with this material in calculating composite damping factors for the modes. Composite damping is used in mode-based procedures that follow subspace iteration eigenvalue extraction or eigenvalue extraction using the Lanczos eigensolver with SIM=NO, except for STEADY STATE DYNAMICS, SUBSPACE PROJECTION. Use the MODAL DAMPING, VISCOUS=COMPOSITE option to activate composite modal damping.

The default is COMPOSITE=0.

DEPENDENCIES

This parameter applies only to Abaqus/Explicit analyses when ALPHA=TABULAR and/or BETA=TABULAR.

Set this parameter equal to the number of field variables included in the definition of the αR and/or βR factors, in addition to temperature. If this parameter is omitted, it is assumed that Rayleigh damping is constant or depends only on temperature. See Specifying Field Variable Dependence for more information.

HIGH FREQUENCY CUTOFF

This parameter applies only to Abaqus/Explicit analyses and is valid only when the BAND LIMITED parameter is used.

Set this parameter equal to the frequency value, f h , to define the upper limit of the frequency range. (Units of cycles/time.)

LOW FREQUENCY CUTOFF

This parameter applies only to Abaqus/Explicit analyses and is valid only when the BAND LIMITED parameter is used.

Set this parameter equal to the frequency value, f l , to define the lower limit of the frequency range. (Units of cycles/time.)

STRUCTURAL

Set this parameter equal to the s factor to create stiffness proportional structural damping in the following procedures:

The default is STRUCTURAL=0.

In Abaqus/Standard set STRUCTURAL=TABULAR to specify that the stiffness proportional structural damping is dependent on temperature.

Data lines to define temperature and/or field variable-dependent mass proportional damping (ALPHA=TABULAR) in Abaqus/Explicit

First line

  1. αR. (Units of T−1.)

  2. Temperature.

  3. First field variable.

  4. Second field variable.

  5. Etc., up to six field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than six)

  1. Seventh field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the alpha damping as a function of temperature and other predefined field variables.

Data lines to define temperature-dependent mass proportional viscous damping (ALPHA=TABULAR) in Abaqus/Standard

First line

  1. αR. (Units of T−1.)

  2. Temperature.

Repeat this data line as often as necessary to define the alpha damping as a function of temperature.

Data lines to define a temperature and/or field variable-dependent damping ratio in band-limited damping (BAND LIMITED=TABULAR) in Abaqus/Explicit

First line

  1. η d .

  2. Temperature.

  3. First field variable.

  4. Second field variable.

  5. Etc., up to six field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than six)

  1. Seventh field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the damping ratio as a function of temperature and other predefined field variables.

Data lines to define temperature and/or field variable-dependent stiffness proportional damping (BETA=TABULAR) in Abaqus/Explicit

First line

  1. βR. (Units of T.)

  2. Temperature.

  3. First field variable.

  4. Second field variable.

  5. Etc., up to six field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than six)

  1. Seventh field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the beta damping as a function of temperature and other predefined field variables.

Data lines to define temperature-dependent stiffness proportional viscous damping (BETA=TABULAR) in Abaqus/Standard

First line

  1. βR. (Units of T.)

  2. Temperature.

Repeat this data line as often as necessary to define the stiffness proportional viscous damping as a function of temperature.

Data lines to define temperature-dependent stiffness proportional structural damping (STRUCTURAL=TABULAR) in Abaqus/Standard

First line

  1. s.

  2. Temperature.

Repeat this data line as often as necessary to define the structural damping as a function of temperature.

Data lines to define both temperature and/or field variable-dependent mass and stiffness proportional damping (both ALPHA=TABULAR and BETA=TABULAR) in Abaqus/Explicit

First line

  1. αR. (Units of T−1.)

  2. βR. (Units of T.)

  3. Temperature.

  4. First field variable.

  5. Second field variable.

  6. Etc., up to five field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)

  1. Sixth field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the alpha and beta damping as a function of temperature and other predefined field variables.

Data lines to define both temperature and/or field variable-dependent mass proportional damping and band-limited damping (both ALPHA=TABULAR and BAND LIMITED=TABULAR) in Abaqus/Explicit

First line

  1. α R . (Units of T−1.)

  2. η d .

  3. Temperature.

  4. First field variable.

  5. Second field variable.

  6. Etc., up to five field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)

  1. Sixth field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the mass proportional and band-limited damping as a function of temperature and other predefined field variables.

Data lines to define both temperature and/or field variable-dependent stiffness proportional damping and band-limited damping (both BETA=TABULAR and BAND LIMITED=TABULAR) in Abaqus/Explicit

First line

  1. β R . (Units of T.)

  2. η d .

  3. Temperature.

  4. First field variable.

  5. Second field variable.

  6. Etc., up to five field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)

  1. Sixth field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the stiffness proportional and band-limited damping as a function of temperature and other predefined field variables.

Data lines to define temperature and/or field variable-dependent mass proportional, stiffness proportional, and band-limited damping (ALPHA=TABULAR, BETA=TABULAR, and BAND LIMITED=TABULAR) in Abaqus/Explicit

First line

  1. α R . (Units of T−1.)

  2. β R . (Units of T.)

  3. η d .

  4. Temperature.

  5. First field variable.

  6. Second field variable.

  7. Etc., up to four field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)

  1. Fifth field variable.

  2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the mass proportional, stiffness proportional, and band-limited damping as a function of temperature and other predefined field variables.

 

See Also
Material Damping
About Dynamic Analysis Procedures
Explicit Dynamic Analysis