Johnson-Cook damage

The Johnson-Cook damage initiation criterion is a special case of the ductile damage criterion model for predicting the onset of damage due to nucleation, growth, and coalescence of voids in ductile metals. The model assumes that the equivalent plastic strain at the onset of damage is a function of stress triaxiality and strain rate. The Johnson-Cook criterion can be used in conjunction with the Mises, Johnson-Cook, Hill, and Drucker-Prager plasticity models, including equation of state.

See Also
Ductile damage
In Other Guides
Damage Initiation for Ductile Metals
  1. From the menu bar in the Edit Material dialog box, select Mechanical Damage for Ductile Metals Johnson-Cook Damage .

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

  2. Enter the material parameter, Accumulation power, equal to the value of the power coefficient, N.
  3. Enter the damage parameters in the Data table:

    d 1 – d 5

    Failure parameters.

    Melting temperature

    θ melt .

    Transition temperature

    θ transition .

    Reference strain rate

    ε ˙ 0

    You might 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.

  4. Select Suboptions Damage Evolution to define the material degradation that takes place once damage begins.

    For more information, see Damage evolution.

  5. Click OK to exit the material editor.