Defining Drucker-Prager hardening

Use the Suboption Editor to specify hardening data for a Drucker-Prager model. For more information on Drucker-Prager hardening, see Hardening and rate dependence.

  1. Create a material model as described in Defining a Drucker-Prager model.”

  2. From the Suboptions menu in the Edit Material dialog box, select Drucker Prager Hardening.

    A Suboption Editor appears.

  3. Select the Hardening behavior type of your choice.

    The evolution of the yield surface with plastic deformation is described in terms of the equivalent stress σ¯, which you can choose to be either the uniaxial Compression yield stress, the uniaxial Tension yield stress, or the Shear (cohesion) yield stress

  4. Toggle on Use strain-rate-dependent data if you want enter data showing yield stress values versus equivalent plastic strain at different equivalent plastic strain rates.

    A Rate column appears in the Data table.

    Alternatively, if you want to define strain rate dependence using yield stress ratios, you must select Rate Dependent from the Suboptions menu in the Edit Material dialog box. See Defining rate-dependent yield with yield stress ratios” for details. For background information on rate dependence, see Rate-dependent yield.

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

    A column labeled Temp appears in the Data table.

  6. 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.

  7. Enter the following data in the Data table:

    Yield Stress

    Yield stress.

    Abs Plastic Strain

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

    Rate

    Equivalent plastic strain rate, ε¯˙pl, for which this hardening curve applies.

    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.

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