Defining creep parameters for a cap plasticity model

The cap creep model has two possible mechanisms that are active in different loading regions: one is a cohesion mechanism, which follows the type of plasticity active in the shear-failure plasticity region, and the other is a consolidation mechanism, which follows the type of plasticity active in the cap plasticity region.

Context:

For more information, see Creep formulation.

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

  2. From the Suboptions menu in the Edit Material dialog box, select either Cap Creep Cohesion or Cap Creep Consolidation. (See Creep formulation, for detailed information on the two creep mechanisms.)

    A Suboption Editor appears.

  3. Click the arrow to the right of the Law field, and select the creep law option of your choice:

    • Select Strain to choose a strain hardening power law.

    • Select Time to choose a time hardening power law

    • Select SinghM to choose a Singh-Mitchell type law.

    • Select User to specify the creep law with user subroutine CREEP.

    For more information, see Specifying creep laws.

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

    A column labeled Temp appears in the Data table.

  5. 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.

  6. If you selected either the Strain or the Time creep law option, enter the following data in the Data table:

    A, n, and m

    Creep material parameters.

    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 you selected the SinghM creep law option, enter the following data in the Data table:

    A, alpha, m, and t1

    Creep material parameters A, α, m, and t1.

    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.