Investigation of the combined effect of notch and fretting on bending fatigue

Quazi Md. Zobaer Shah, Md. Arefin Kowser, Mohammad Asaduzzaman Chowdhury

Being a common phenomenon in failure mechanism, fretting fatigue has emerged as one of the major concerns in recent years both in research and industrial applications. In the present study, the effect of notch and fretting on bending fatigue has been examined by FEM analysis. Based on the available and validated FEM model, analyses have been carried out on single point fretting with a double notch and double point fretting with a single notch respectively. Along the predefined paths through the edge, thickness and notch, fatigue behavior and stress-strain distribution have been studied. It has been found that stress and strain distribution is uniformly spaced for constant fretting loads with a variable concentric load whereas variable fretting loads yield almost two times results. Stress and strain singularity is found for transverse loading when highly stressed. Peak stress was found on the stress distribution path for fretting action for the combined fretting and notch presence. Fatigue life was influenced more drastically by variable fretting loads than variable concentric loadings only in case of tension. Dual action of fretting with notches was found more detrimental than the single action of double fretting/notching.