Forming limit stress diagram (FLSD) damage

The FLSD damage initiation criterion is intended to predict the onset of necking instability in sheet metal forming. The strain-based forming limit curves (as used in the FLD criterion) are converted to stress-based curves to reduce the dependence on the strain path. This improves the performance of the FLSD damage model under conditions of arbitrary loading.

Context:

Similar to the FLD criterion, damage due to bending deformation cannot be evaluated using this model. For more information, see Damage initiation for ductile metals.

  1. From the menu bar in the Edit Material dialog box, select MechanicalDamage for Ductile MetalsFLSD Damage.

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

  2. To define material damage data that depend on temperature, toggle on Use temperature-dependent data.

    A column labeled Temp appears in the Data table.

  3. 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.

    Field variable columns appear in the Data table.

  4. Enter damage parameters in the Data table:

    Major Principal Stress

    The maximum value of the in-plane principal limit stress.

    Minor Principal Stress

    The minimum value of the in-plane principal limit stress.

    Temp

    Temperature, θ.

    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.

  5. Select SuboptionsDamage Evolution to define the material degradation that takes place once damage begins.

    For more information, see Damage evolution.”

  6. Click OK to exit the material editor.