Using an isotropic hardening model to define classical metal plasticity

The isotropic hardening model is useful for cases involving gross plastic straining or for cases where the straining at each point is essentially in the same direction in strain space throughout the analysis.

  1. From the menu in the Edit Material dialog box, select Mechanical Plasticity Plastic .

    (For information on displaying the Edit Material dialog box, see Creating or editing a material.)

  2. Click the arrow to the right of the Hardening field, and select Isotropic.
  3. Select Use strain-rate-dependent data if you want enter test 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. See Defining rate-dependent yield with yield stress ratios” for details. For background information on rate dependence, see Rate-Dependent Yield.

  4. Select Use temperature-dependent data to define behavior data that depend on temperature.

    A column labeled Temp appears in the Data table.

  5. To define behavior data that depend on field variables, click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables.
  6. Enter the following data in the Data table:

    Yield Stress

    The stress at which yield is initiated.

    Plastic Strain

    Plastic strain.

    Rate

    Equivalent plastic strain rate, ε¯˙p⁢l, for which the stress-strain 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.

  7. If desired, use the Suboptions menu to enter additional data.

    See the following sections for details:

  8. Click OK to create the material and to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (For more information, see Browsing and modifying material behaviors.)