Fatigue Life Prediction of Notched Specimens Using a new model in the framework of Entropy Generation Theory

In this paper, a new entropy based criterion is proposed, and applied to fatigue life prediction of the notchedspecimens subjected to remote constant amplitude displacement. The hypothesis of proposed approach is, theaccumulation of generated entropy up to the final failure might be constant, independent of load, geometry andfrequency. The plastic energy measured from hysteresis loops of fatigue loading considered as the only driver ofentropy generation. In order to extract hysteresis loop of fatigue cycles, an elasto-plastic constitutive model is employedconsidering the non-linear kinematic hardening of Chaboche in the ABAQUS software capabilities. The results ofproposed approach are evaluated by fatigue test results of the Al-7075-T6 and Al-2024-T42 specimens subjected totension-tension loading. Finally, by comparing the results of the proposed method with the obtained results of wellknownstrain based criteria, it is shown that the proposed method has a more accurate prediction lives than othermethods.

Keywords:

Notch , Entropy , Strain based criterion , Low cycle