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*CLAY HARDENING
Specify hardening for the clay plasticity model.

This option is used to define piecewise linear hardening/softening of the Cam-clay plasticity yield surface. It can be used only in conjunction with the *CLAY PLASTICITY 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, in addition to temperature, included in the definition of the hydrostatic pressure stress. If this parameter is omitted, the hydrostatic pressure stress may depend only on the volumetric plastic strain and, possibly, on the temperature. See “Specifying field variable dependence” in “Material data definition,” Section 21.1.2 of the Abaqus Analysis User's Guide, for more information.

SR

This parameter is relevant only when the *SOFTENING REGULARIZATION option is used.

Set SR=ON (default) to use softening regularization for the clay hardening data.

Set SR=OFF if softening regularization is not required.

TYPE

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

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

Compression hardening must always be defined. Tensile hardening is optional and can be specified, if needed, by repeating the *CLAY HARDENING option with TYPE=TENSION.

Data lines to define hardening for Cam-clay plasticity: 

First line:

  1. Value of the hydrostatic pressure stress at yield, or . is given as a positive value and must increase with increasing plastic strain. can be zero or a negative value and must decrease with increasing plastic strain.

  2. Absolute value of the corresponding compressive volumetric plastic strain. The first tabular value 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 the yield surface size on volumetric plastic strain and, if needed, on temperature and other predefined field variables.