*DASHPOT

Define dashpot behavior.

This option is used to define the dashpot behavior for dashpot elements.

In Abaqus/Standard analyses it is also used to define the dashpot behavior for ITS and JOINTC elements. If the DASHPOT option is being used to define part of the behavior of ITS or JOINTC elements, it must be used in conjunction with the ITS or JOINT options and the ELSET and ORIENTATION parameters should not be used.

Related Topics
In Other Guides
Dashpots
Flexible joint element
Tube support elements

ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE

TypeModel data

LevelPartPart instanceAssembly

Abaqus/CAEProperty module and Interaction module; supported only for linear behavior independent of field variables. For nonlinear behavior or to include field variables, model connectors in the Interaction module.

Required parameter if the behavior of dashpot elements is being defined

ELSET

Set this parameter equal to the name of the element set containing the dashpot elements for which this behavior is being defined.

Optional parameters

DEPENDENCIES

Set this parameter equal to the number of field variable dependencies included in the definition of the dashpot coefficient, in addition to temperature. If this parameter is omitted, it is assumed that the dashpot coefficient is independent of field variables. See Material data definition for more information.

NONLINEAR

Include this parameter to define nonlinear dashpot behavior. Omit this parameter to define linear dashpot behavior.

ORIENTATION

This parameter applies only to Abaqus/Standard analyses.

If the option is being used to define the behavior of DASHPOT1 or DASHPOT2 elements, this parameter can be used to refer to an orientation definition so that the dashpot is acting in a local system. Set this parameter equal to the name of the ORIENTATION definition (Orientations).

RTOL

This parameter applies only to Abaqus/Explicit analyses.

Set this parameter equal to the tolerance to be used for regularizing the material data. The default is RTOL=0.03. See Material data definition for a discussion of data regularization.

Data lines to define linear dashpot behavior for DASHPOTA or ITS elements

First line

  1. Enter a blank line.

Second line

  1. Dashpot coefficient (force per relative velocity).

  2. In an Abaqus/Standard analysis this field corresponds to frequency (in cycles per time, for STEADY STATE DYNAMICS, DIRECT and STEADY STATE DYNAMICS, SUBSPACE PROJECTION analyses only). Leave this field blank in an Abaqus/Explicit analysis.

  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 dashpot coefficient as a function of frequency, temperature, and other predefined field variables.

Data lines to define nonlinear dashpot behavior for DASHPOTA or ITS elements

First line

  1. Enter a blank line.

Second line

  1. Force.

  2. Relative velocity.

  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 dashpot coefficient as a function of temperature and other predefined field variables.

Data lines to define linear dashpot behavior for DASHPOT1, DASHPOT2, or JOINTC elements

First line

  1. Give the degree of freedom with which the dashpots are associated at their first nodes or, for JOINTC elements, the degree of freedom in the local corotational system for which the dashpot behavior is being defined.

  2. For DASHPOT2 elements give the degree of freedom with which the dashpots are associated at their second nodes.

If the ORIENTATION parameter is included on the DASHPOT option when defining dashpot elements or on the JOINT option when defining joint elements, the degrees of freedom specified here are in the local system defined by the ORIENTATION option referenced.

Second line

  1. Dashpot coefficient (force per relative velocity).

  2. Frequency (in cycles per time, for STEADY STATE DYNAMICS, DIRECT and STEADY STATE DYNAMICS, SUBSPACE PROJECTION analyses only).

  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 variables per line.

Repeat this set of data lines as often as necessary to define the dashpot coefficient as a function of frequency, temperature, and other predefined field variables.

Data lines to define nonlinear dashpot behavior for DASHPOT1, DASHPOT2, or JOINTC elements

First line

  1. Give the degree of freedom with which the dashpots are associated at their first nodes or, for JOINTC elements, the degree of freedom in the local corotational system for which the dashpot behavior is being defined.

  2. For DASHPOT2 elements give the degree of freedom with which the dashpots are associated at their second nodes.

If the ORIENTATION parameter is included on the DASHPOT option when defining dashpot elements or on the JOINT option when defining joint elements, the degrees of freedom specified here are in the local system defined by the ORIENTATION option referenced.

Second line

  1. Force.

  2. Relative velocity.

  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 dashpot coefficient as a function of temperature and other predefined field variables.