Effect of Equivalent Stress Amplitude on Multiaxial Fretting Fatigue Behavior of Al–Zn–Mg Alloy

The fretting fatigue behavior in Al–Zn–Mg alloy is investigated under conditions of various equivalent stress amplitudes of cyclic multiaxial loadings and the same contact pressure with a point contact. The ANSYS finite element analysis is used to analyze stress distribution by a numerical study using the 3D finite element method. Fretting regions’ morphology and fracture of specimens are characterized by scanning electron microscopy. Results obtained indicate that at the contact stress of 180 MPa, with increasing of equivalent stress amplitude, the degree of cyclic softening under tension/torsional fretting fatigue loading increases, and the fretting fatigue durability drops with the equivalent stress amplitude. The different equivalent stress amplitudes play a very important role in fretting regions’ morphology and fracture forming. Their influence on the fretting fatigue life is discussed by the comparison of the experimental results.