In HEAT the total damage for thermomechanical fatigue consists of three terms:
Dmech ... the mechanical damage component according to COFFIN/MANSON
Dox ....... the oxidation damage/ambient damage component
Dcreep ... the creep damage component
Dtotal = Dmech + Dox + Dcreep
In the oxidation damage according to BOISMIER, KADIOGLU and SEHITOGLU the oxidation phase Fox and the strain rate (e) are very highly dependent on the strain history over time.
Creep damage is most prominent for an in-phase TMF load (mechanical loads enhance thermal strain) and is integrated over the cycle time.
This naturally implies that damage is time-dependent.
The time information (unit: seconds) can be defined in a number of ways. Either the step time from the stress, strain or temperature results can be used (which makes more uncommon step time definitions necessary) or a separate table is imported as a text file. This can be performed on the "Time information" tab.