Fretting Fatigue Life Estimations Based on the Critical Distance Stress Theory.

Abstract: Generally fretting fatigue S-N curve have two stages, one is high cycle (low stress) region and second is low cycle (high stress) region. In previous paper we introduced the fretting fatigue life estimation methods in high cycle region by considering the wear process. And in this estimation method the fretting fatigue limit can be estimated as the crack initiation limit at contact edge. In this paper we estimated the low cycle fretting fatigue life based on new critical distance theory, which is modified for high stress region using ultimate tensile strength σB, and fracture toughness KIC. Firstly the critical distance for estimating low cycle fatigue strength was calculated by interpolation of critical distance on fatigue limit (estimated from σw0 and ΔKth) with critical distance on static strength (estimated from σB and KIC). The validity of this method is confirmed by the V notch specimens. And then we applied this method on estimation of low cycle fretting fatigue strength and life. By unifying these low cycle fretting fatigue life estimation method with high cycle fretting fatigue life estimation method which was presented previous paper we can estimate the total fretting life easily. And to confirm the availability of this estimation method we perform the fretting fatigue test using Ni-Mo-V steel. [Copyright &y& Elsevier]