The Material failure can be classified into several types failure including fatigue which is also classified into plain fatigue and fretting fatigue. Many studies were carried out to understand the behavior of the material under the condition of one those two types only. None of the previous studies considered testing the material under a combination between plain and fretting fatigue where most of the components in engineering and industrial application subjected to. This study is directed to that end. Five tests were conducted with different ratio between the plain and fretting fatigue. When half of the whole fretting fatigue life was applied initially and then followed by the plain fatigue cycles until a failure, the plain fatigue was found to have no impact on the material life comparing to fretting fatigue. This shows that most of the fretting fatigue life is expended in the crack initiation. The ratio between the plain fatigue and the fretting fatigue has significant effect on fatigue life. If this ratio decreases the effect of the fretting fatigue increases that results in reduction of the fatigue life. This study was done under constant contact load, so it is recommended to investigate the material under combination between plain and fretting fatigue with variable contact load
Contact mechanics is concerned with the behavior of two materials in contact with each other under various load conditions. Many experimental studies were conducted to give a better understanding of this phenomenon as it is affected by several factors. It is imperative to incorporate the numerical methods in predicating such behavior for the sake of time and money. This study focused on the finite element analysis (FEA) using ABAQUS software program to investigate the parameter affecting the life of the materials in contact with each other. The data of this study was based on the experimental work conducted on Titanium Alloy under phase difference between the axial and contact load. The result from this study was also compared to the analytic solution for the contact mechanics as well as the experimental one. Findings show that the FEA was in a very good agreement with the Ruiz program and other experimental studies. The greatest value of tangential load to contact load ratio was found at in-phase condition while the Modified Shear Stress Range (MSSR) was higher for the out-of-phase condition. This result shows an increase of 145% in the fatigue life for the out-of-phase condition in comparison to in-phase condition. So the FEA can be adopted to predict the material fatigue life and the crack initiation location and orientation.