LAUSR

Abstract The fretting fatigue behavior of functionally graded material (FGM) coatings under the out-of-phase loading condition is investigated in this work. A numerical model is developed by using the finite element method. Dimensional analysis is utilized to identify various dimensionless variables that are involved in associated quantities of interest. The effects of interface stiffness ratio, inhomogeneity index of the FGM coating and loading phase are examined on the contact width, contact pressure, stresses as well as the damage initiation location induced by the fretting fatigue. It is found that both the magnitude and distribution of stresses are sensitive to the out-of-phase loading. The contact surface traction, interfacial stresses and the initiation location of fretting damage can be effectively adjusted by varying the characteristic parameters of the FGM coating. These results are expected to provide a promising approach to enhance the fretting fatigue resistance of materials via FGM coating design.