.. code-block:: sierrainput

   #
     #
     # Hardening model
     #
     HARDENING MODEL = LINEAR | POWER_LAW | VOCE | USER_DEFINED |
     FLOW_STRESS | DECOUPLED_FLOW_STRESS | JOHNSON_COOK | 
     POWER_LAW_BREAKDOWN
     #
     # Linear hardening
     #
     HARDENING MODULUS = <real>
     #
     # Power-law hardening
     #
     HARDENING CONSTANT = <real>
     HARDENING EXPONENT = <real> (0.5)
     LUDERS STRAIN      = <real> (0.0)
     #
     # Voce hardening
     #
     HARDENING MODULUS       = <real>
     EXPONENTIAL COEFFICIENT = <real>
     #
     # Johnson-Cook hardening
     #
     HARDENING FUNCTION = <string>hardening_function_name
     RATE CONSTANT      = <real>
     REFERENCE RATE     = <real>
     #
     # Power law breakdown hardening
     #
     HARDENING FUNCTION = <string>hardening_function_name
     RATE COEFFICIENT   = <real>
     RATE EXPONENT      = <real>
     # User defined hardening
     #
     HARDENING FUNCTION = <string>hardening_function_name
     #
