Effects of Stress-Relieving Slots on Fretting Fatigue Behavior of Ti-6Al-4V

Fretting is a complex phenomenon, it alters the stress and strain fields in the contact region between two bodies, due to micro-slip, which decreases the fatigue resistance of materials. This study investigates the effect of stress-relieving slots, machined in flat pads, on the fretting fatigue behavior of Ti-6Al-4V alloy. Three types of slots including U-notch, V-notch, and a simple hole were used. Conventional fretting fatigue model, involving a contact between a flat pad with rounded edges and a fatigue specimen loaded by a cyclic axial load, was used. Several fretting fatigue parameters such as the maximum tensile stress, Smith Watson Topper, Maximum Shear Stress Range, and MSSR parameters were considered for this study. The stress, strain, and displacement distribution in the contact region of fatigue specimen were computed using the finite element analysis code ABAQUS. The data were used to calculate the fretting fatigue parameters and evaluate the effectiveness of the slots in improving the fretting fatigue resistance. The analytical results were verified by the experimental data.