Influence of contact configuration in fretting fatigue testing

Abstract

Fretting fatigue tests are typically performed using either a flat-on-flat or a cylinder-on-flat contact configuration. To obtain a better understanding of the behavior of these two configurations, both contact configurations were imposed simultaneously on opposite sides of a fretting fatigue specimen under the same nominal contact load. The evolution of the surface and subsurface damage on both sides was characterized by measuring the frictional force/displacement hysteresis, and by post-test examination with a scanning electron microscope (SEM). Tests were performed on PH 13-8 Mo, a high strength martensitic stainless steel. Although the major fatigue crack which led to specimen failure always occurred at a cylinder-on-flat contact, a crack was often observed at a flat-on-flat site. Significant differences in the early evolution of damage between the two contact configurations were observed.