Fundamental Investigations of Fretting Fatigue : Part 6, Effects of Contact Pressure and Hardness of Materials

Abstract

Fretting fatigue tests have been made about the effect of clamping pressure, p₀, and hardness of materials on the initiation of non-propagating cracks and also complete fracture under the conditions where the relative slip is fully controlled. The main results obtained are as follows. (1) Fretting fatigue strength based on the initiation of fatigue cracks, σ_w1, decreases linearly with the increase of p₀. (2) Fretting fatigue strength based on fracture, σ_w2, decreases gradually with the increase of contact pressure, and reaches a critical strength when p₀ is beyond a certain value. (3) These results in (1) and (2) are analogous to fatigue phenomena of notched specimens, when the stress concentration caused by fretting is considered. (4) When the relative slip of fretting is relatively large, σ_w1 is affected by the susceptibility of materials to wear.