Influence of fretting fatigue parameters on fatigue life and crack orientation

Coupled metallic structural components, subjected to vibrations or small oscillatory movements, are prone to fretting, which can significantly affect their fatigue behaviour. Despite the numerous efforts in recent decades to investigate the influence of fretting parameters (such as fretting loading, friction coefficient, relative slip amplitude, contact geometry, surface finishing, different materials, testing environment) on the fatigue behaviour of the analysed components, research in this field is still open. In the present paper, experimental tests available in the literature, carried out on Al-4Cu specimens in partial slip regime with cylindrical fretting pads, are simulated through an analytical methodology proposed by the present authors. Satisfactory results in terms of both crack orientation and fatigue life are obtained by employing such a methodology. Then, a parametric study on the fretting parameters used as input data for this analytical methodology is performed in the present research work, in order to evaluate their influence on the fatigue life and crack orientation of fretting-affected structural components.