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*DRUCKER PRAGER HARDENING
Specify hardening for Drucker-Prager plasticity models.

This option is used to specify the hardening data for elastic-plastic materials that use any of the generalized Drucker-Prager yield criteria defined in the *DRUCKER PRAGER option.

This option is also used in Abaqus/Standard analyses to specify the type of creep test with which the creep laws defined in the *DRUCKER PRAGER CREEP option are measured. It must be used in conjunction with the *DRUCKER PRAGER option and, if creep material behavior is included in an Abaqus/Standard analysis, with the *DRUCKER PRAGER CREEP option.

Products: Abaqus/Standard  Abaqus/Explicit  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 yield stress, in addition to temperature. If this parameter is omitted, the yield stress depends only on the plastic strain and, possibly, on temperature. See “Using the DEPENDENCIES parameter to define field variable dependence” in “Material data definition,” Section 21.1.2 of the Abaqus Analysis User's Guide, for more information.

RATE

Set this parameter equal to the equivalent plastic strain rate, , for which this hardening curve applies. This parameter should be omitted if the *RATE DEPENDENT option or the *DRUCKER PRAGER CREEP option is used. Rate-independent behavior is assumed if the RATE parameter, the *RATE DEPENDENT option, and the *DRUCKER PRAGER CREEP option are not used.

TYPE

Set TYPE=COMPRESSION (default) to define the hardening behavior by giving the uniaxial compression yield stress, , as a function of uniaxial compression plastic strain, .

Set TYPE=TENSION to define the hardening behavior by giving the uniaxial tension yield stress, , as a function of uniaxial tension plastic strain, .

Set TYPE=SHEAR to define the hardening behavior by giving the cohesion, , as a function of equivalent shear plastic strain, , where is the yield stress in shear, K is the ratio of flow stress in triaxial tension to the flow stress in triaxial compression, and is the engineering shear plastic strain.

Data lines to define Drucker-Prager hardening: 

First line:

  1. Yield stress.

  2. Absolute value of the corresponding plastic strain. (The first tabular value entered must always be zero.)

  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 dependence of yield stress on plastic strain and, if needed, on temperature and other predefined field variables.