Fatigue life estimation of notched specimens under bending and torsion with strain energy density parameter

This paper presents an energy damage parameter based on the critical plane under a complex loading state and stress concentration. Two criteria including combinations of the normal and shear strain energy density parameters have been proposed. The plane in which the normal or shear strain energy density parameter reaches its maximum is assumed to be the critical plane. The predictions of the proposed model have been compared with constant amplitude fatigue tests under combined proportional bending and torsion carried out on ring-notched specimens made of 42CrMo4V steel.