Defining tensile clay hardening for a clay plasticity model

The Suboption Editor allows you to provide the hydrostatic tensile yield stress as a function of volumetric plastic strain to define piecewise linear hardening/softening of the Cam-clay plasticity yield surface. For more information on this form of the hardening law, see Piecewise linear form.

  1. Create a material model as described in Specifying clay plasticity behavior.”

  2. From the Suboptions menu in the Edit Material dialog box, select Tensile Clay Hardening.

    A Suboption Editor appears.

  3. Toggle on Use temperature-dependent data to define data that depend on temperature.

    A column labeled Temp appears in the Data table.

  4. Click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables on which the data depend.

  5. In the Data table, enter the following data:

    Yield Stress

    Value of the hydrostatic pressure stress at yield, pt. pt can be zero or a negative value and must decrease with increasing volumetric plastic strain.

    Vol Plas Strain

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

    Temp

    Temperature.

    Field n

    Predefined field variables.

    You may need to expand the dialog box to see all the columns in the Data table. For detailed information on how to enter data, see Entering tabular data.

  6. Click OK to return to the Edit Material dialog box.