Fatigue life prediction under variable loading based on a new non-linear continuum damage mechanics model

This work presents a non-linear continuum damage mechanics model based on general thermodynamic framework developed by Lemaitre and Chaboche. The proposed model has been formulated to take into account the material damage evolution at different load levels and it allows the effect of the loading sequence to be included; by means of a recurrence formula derived for multilevel loading, complex load sequences can be considered. The fatigue test data for a hardened and tempered steel have been used to verify the model proposed in this paper and the results show a good agreement to predict fatigue life under complex load sequences.