Abaqus Keywords Reference Manual  

*VISCOSITY
Specify material shear viscosity.

This option is used to specify the shear viscosity of the material. It must be used in conjunction with the *EOS option.

Products: Abaqus/Explicit  Abaqus/CFD  Abaqus/CAE  

Type: Model data

Level: Model  

Abaqus/CAE: Property module

References:

Optional parameters:

DEFINITION

Set DEFINITION=CARREAU-YASUDA to define the Carreau-Yasuda viscous shear behavior.

Set DEFINITION=CROSS to define the Cross viscous shear behavior.

Set DEFINITION=ELLIS-METER to define the Ellis-Meter viscous shear behavior.

Set DEFINITION=HERSCHEL-BULKEY to define the Herschel-Bulkey viscous shear behavior.

Set DEFINITION=NEWTONIAN (default) to define Newtonian (linear) viscous shear behavior.

Set DEFINITION=POWELL-EYRING to define the Powell-Eyring viscous shear behavior.

Set DEFINITION=POWER LAW to define the power law viscous shear behavior.

Set DEFINITION=TABULAR to define the non-Newtonian viscous shear behavior in tabular form.

Set DEFINITION=USER to define the viscous shear behavior in user subroutine VUVISCOSITY.

DEPENDENCIES

Set this parameter equal to the number of field variable dependencies included in the definition of the viscosity, in addition to temperature. If this parameter is omitted, it is assumed that the viscosity depends only on temperature. See “Using the DEPENDENCIES parameter to define field variable dependence” in “Material data definition,” Section 18.1.2 of the Abaqus Analysis User's Manual, for more information.

PROPERTIES

This parameter can be used only if DEFINITION=USER is specified.

Set this parameter equal to the number of property values needed as data in user subroutine VUVISCOSITY. The default value is 0.

Data lines to define the Carreau-Yasuda viscous shear behavior (DEFINITION=CARREAU-YASUDA): 

First line:

  1. Shear viscosity at low shear rates (Newtonian limit), . (Units of FL–2T.)

  2. Shear viscosity at large shear rates, . (Units of FL–2T.)

  3. Time constant, . (Units of T.)

  4. Flow behavior index, .

  5. .

  6. Temperature.

  7. First field variable.

  8. Second field variable.

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

  1. Third field variable.

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

Repeat this set of data lines as often as necessary to define the coefficients of the Carreau-Yasuda viscosity model as a function of temperature and other predefined field variables.

Data lines to define the Cross viscous shear behavior (DEFINITION=CROSS): 

First line:

  1. Shear viscosity at low shear rates (Newtonian limit), . (Units of FL–2T.)

  2. Shear viscosity at large shear rates, . (Units of FL–2T.)

  3. Time constant, . (Units of T.)

  4. Flow behavior index, .

  5. Temperature.

  6. First field variable.

  7. Second field variable.

  8. Third field variable.

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

  1. Fourth field variable.

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

Repeat this set of data lines as often as necessary to define the coefficients of the Cross viscosity model as a function of temperature and other predefined field variables.

Data lines to define the Ellis-Meter viscous shear behavior (DEFINITION=ELLIS-METER): 

First line:

  1. Shear viscosity at low shear rates (Newtonian limit), . (Units of FL–2T.)

  2. Shear viscosity at large shear rates, . (Units of FL–2T.)

  3. Effective shear stress, , at which the viscosity is 50% between the Newtonian limit, , and the infinite shear viscosity, . (Units of FL–2.)

  4. Flow behavior index, .

  5. Temperature.

  6. First field variable.

  7. Second field variable.

  8. Third field variable.

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

  1. Fourth field variable.

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

Repeat this set of data lines as often as necessary to define the coefficients of the Ellis-Meter viscosity model as a function of temperature and other predefined field variables.

Data lines to define the Herschel-Bulkey viscous shear behavior (DEFINITION=HERSCHEL-BULKEY): 

First line:

  1. Shear viscosity at low shear rates, . (Units of FL–2T.)

  2. Yield shear stress, . (Units of FL–2.)

  3. Consistency index, . (Units of FL–2Tn.)

  4. Flow behavior index, .

  5. Temperature.

  6. First field variable.

  7. Second field variable.

  8. Third field variable.

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

  1. Fourth field variable.

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

Repeat this set of data lines as often as necessary to define the coefficients of the Herschel-Bulkey viscosity model as a function of temperature and other predefined field variables.

Data lines to define Newtonian viscous shear behavior (DEFINITION=NEWTONIAN): 

First line:

  1. Viscosity. (Units of FL–2T.)

  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 viscosity as a function of temperature and other predefined field variables.

Data lines to define the Powell-Eyring viscous shear behavior (DEFINITION=POWELL-EYRING): 

First line:

  1. Shear viscosity at low shear rates (Newtonian limit), . (Units of FL–2T.)

  2. Shear viscosity at large shear rates, . (Units of FL–2T.)

  3. Time constant, . (Units of T.)

  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 coefficients of the Powell-Eyring viscosity model as a function of temperature and other predefined field variables.

Data lines to define the power law viscous shear behavior (DEFINITION=POWER LAW): 

First line:

  1. Consistency index, . (Units of FL–2Tn.)

  2. Flow behavior index, .

  3. Maximum viscosity, . (Units of FL–2T.)

  4. Minimum viscosity, . (Units of FL–2T.)

  5. Temperature.

  6. First field variable.

  7. Second field variable.

  8. Third field variable.

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

  1. Fourth field variable.

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

Repeat this set of data lines as often as necessary to define the coefficients of the power law viscosity model as a function of temperature and other predefined field variables.

Data lines to define the viscous shear behavior in tabular form (DEFINITION=TABULAR): 

First line:

  1. Viscosity, . (Units of FL–2T.)

  2. Effective shear strain rate, . (Units of T–1.)

  3. Temperature.

  4. First field variable.

  5. Second field variable.

  6. 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 viscosity as a function of effective shear strain rate, temperature, and other predefined field variables.

Data lines to define the material properties for the user-defined viscosity model (DEFINITION=USER): 

No data lines are needed if the PROPERTIES parameter is omitted or set to 0. Otherwise, first line:

  1. Give the material properties, eight per line.

Repeat this data line as often as necessary to define the material properties.