Investigation into Tangential Force and Axial Stress Effects on Fretting Fatigue Behavior

Fretting fatigue behavior of a titanium alloy was investigated using a dual actuator test setup which was capable to apply the pad displacement independent of the applied cyclic load on specimen. Fretting fatigue tests were conducted using this setup with a phase difference between cyclic load on the specimen and tangential force on the fretting pad with cylinder-on-flat contact configuration under partial slip condition. Two axial stress ratios were used. The relative slip range and tangential force range were related to each other and this relationship was not influenced by phase difference, axial stress ratio, and contact load under the partial slip condition. Change in the phase difference caused the change in relative slip as well as tangential force for a given applied pad displacement and axial load. However, there was no effect of phase difference on fretting fatigue life at a given relative slip level. Fretting fatigue tests with a fully reversed axial stress showed longer fatigue life than tension-tension counterparts at a given relative slip, tangential force range, and axial stress range. Finite element analysis was conducted by including the complete load history effects, which showed that stress distribution on the contact surface stabilized after the first fatigue cycle. Unlike relative slip and∕or tangential force range, a critical plane-based parameter appears to take into account the stress ratio effects to characterize fretting fatigue behavior.