The Role of Fretting Wear in Fretting Fatigue Damage of Press-fitted Shaft

초록

Fretting wear and fretting fatigue occurs concurrently in most fretting environment. In this paper, we focus on the effect of fretting wear on fretting fatigue damage of press-fitted shaft through the analytical attempts based on experimental data. A finite element analysis was performed to analyze the evolution of contact variables due to fretting wear, considering the worn surface profiles of shaft measured from experiment. The evolutions of fretting fatigue damage as wearing of contact surface were evaluated by stress-life approach using fatigue notch factor. It is found that the distribution of contact pressure and stress concentration at the contact edge of press-fitted shaft varies rapidly as a result of fretting wear at the initial stage of total fatigue life. Furthermore, the presence of fretting wear in the contact surface of press fits led to the remarkable reduction of fretting fatigue damage. Therefore, it is suggested that the evolution of contact variables in consequence of material removal needs to be incorporated on fretting fatigue life prediction of press fits.