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*CREEP
Define a creep law.

This option is used when metal creep behavior is to be included in a material definition. Metal creep behavior defined is active only during *DIRECT CYCLIC; *SOILS, CONSOLIDATION; *COUPLED TEMPERATURE-DISPLACEMENT; *STEADY STATE TRANSPORT; and *VISCO procedures. This option can also be used to define creep behavior in the thickness direction in a gasket; in this case the option is active only during the *VISCO procedure.

Products: Abaqus/Standard  Abaqus/CAE  

Type: Model data

Level: Model  

Abaqus/CAE: Property module

References:

Optional parameters:

DEPENDENCIES

Set this parameter equal to the number of field variable dependencies included in the definition of the creep constants in addition to temperature. If this parameter is omitted, it is assumed that the creep constants have no dependencies or depend only on temperature. See “Specifying field variable dependence” in “Material data definition,” Section 21.1.2 of the Abaqus Analysis User's Guide, for more information.

LAW

Set LAW=STRAIN (default) to choose a strain-hardening power law.

Set LAW=TIME to choose a time-hardening power law.

Set LAW=HYPERB to choose a hyperbolic-sine law.

Set LAW=USER to input the creep law using user subroutine CREEP.

Set LAW=ANAND to choose an Anand law.

Set LAW=DARVEAUX to choose a Darveaux law.

Set LAW=DOUBLE POWER to choose a double power law.

TIME

This parameter is relevant only when LAW=TIME is used.

Set TIME=CREEP to use creep time in the time-hardening relation.

Set TIME=TOTAL (default) to use total time in the time-hardening relation.

Data lines for LAW=TIME or LAW=STRAIN: 

First line:

  1. A. (Units of FLT.)

  2. n.

  3. m.

  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 dependence of the creep constants on temperature and other predefined field variables.

Data lines for LAW=HYPERB: 

First line:

  1. A. (Units of T–1.)

  2. B. (Units of F–1L2.)

  3. n.

  4. . (Units of JM–1.) (This value can be left blank if temperature dependence is not needed.)

  5. R. (Units of JM–1–1.)

  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 dependence of the creep constants on predefined field variables.

Data lines for LAW=ANAND: 

First line:

  1. S1. (Units of FL–2.)

  2. . (Units of .)

  3. A. (Units of T–1.)

  4. .

  5. m.

  6. A0. (Units of FL–2.)

  7. . (Units of FL–2.)

  8. n.

Second line:

  1. a.

  2. S2. (Units of FL–2.)

  3. S3. (Units of FL–2.)

  4. A1. (Units of FL–2.)

  5. A2. (Units of FL–2.)

  6. A3. (Units of FL–2T.)

  7. A4. (Units of FL–2T2.)

Data lines for LAW=DARVEAUX: 

First line:

  1. Css. (Units of T–1.)

  2. . (Units of .)

  3. . (Units of F–1L2.)

  4. n.

  5. .

  6. B.

Data lines for LAW=DOUBLE POWER: 

First line:

  1. A1. (Units of T–1.)

  2. B1. (Units of .)

  3. C1.

  4. A2. (Units of T–1.)

  5. B2. (Units of .)

  6. C2.

  7. . (Units of FL–2.)