Session: 13-11-03: Friction, Fracture, and Damage III

Paper Number: 164198

The Complex Roles of Friction and Surface Roughness on Fretting Fatigue: A Literature Review 

Friction plays a fundamental role in many mechanical failures, particularly in tribological contact conditions where repeated loading and relative motion occur. Fretting is a specific type of contact damage that arises when two surfaces experience small-amplitude oscillatory motion under normal compressive loading. This process leads to significant stress concentrations, surface wear, and the initiation of cracks, which can propagate and result in catastrophic failures. Among the various failure modes influenced by fretting, fretting fatigue is of particular concern due to its ability to significantly reduce the life of structural components.

Keywords: Friction, Fretting Fatigue, Fretting Fatigue Modeling, Additive Manufacturing.

Fretting fatigue occurs in components subjected to cyclic loads with restricted relative motion at the contact interface, leading to localized damage and crack initiation. It is influenced by many factors, including microstructure, surface condition, contact geometry, slip amplitude, friction between contact surfaces, temperature, frequency, and the distribution and magnitude of stresses. This phenomenon is prevalent in many critical applications such as bolted lap joints, press-fit connections, splined couplings, power transmissions, bio-implants, bearing shafts, bolted and riveted connections, and turbine blade dovetail roots. The interaction between friction and fretting fatigue is complex, as it directly influences stress distributions, slip amplitudes, and wear mechanisms. High friction levels can increase tangential stresses and promote crack initiation, whereas lower friction values may enhance wear damage and modify fatigue life. A precise understanding of this interaction is essential for predicting fretting fatigue behavior and improving fatigue-resistant designs.

Predictive models for fretting fatigue typically fall into two categories: (1) multiaxial fatigue models, such as the Fatemi–Socie and Smith–Watson–Topper parameters, and (2) surface damage models, such as the Ruiz parameter. Numerical approaches, particularly Finite Element (FE) methods, offer powerful tools for modeling stress distributions and crack initiation mechanisms under fretting conditions. However, incorporating realistic frictional effects into these models remains a challenge due to variations in surface conditions, lubrication, and material properties. Despite the development of numerous predictive models for fretting fatigue, a universal approach that accurately captures its complexity across different materials and loading conditions has yet to be established. Additionally, improving fretting fatigue resistance remains a crucial engineering challenge.

As Additive Manufacturing (AM) gains increasing adoption in engineering applications, understanding the role of friction and fretting fatigue in AM metals has become a critical research area. The different features inherent in AM materials can significantly alter key fretting fatigue influencing factors such as surface conditions, stress distributions, and microstructure. These unique characteristics can lead to modified contact mechanics and fatigue performance compared to conventionally manufactured materials. AM may also present effective approaches for mitigating fretting fatigue, which would be extremely challenging, if not impossible, to achieve through conventional techniques. Such strategies include microstructural control, surface texturization, and the introduction of stress-relieving grooves and voids to redistribute contact stresses and delay crack initiation. Adapting existing fretting fatigue models to incorporate these AM-specific characteristics is essential for ensuring accurate life predictions and optimizing AM component designs for fatigue resistance.

This study synthesizes experimental findings, numerical modeling efforts, and mitigation strategies related to friction in fretting fatigue. It evaluates the impact of frictional forces on fretting fatigue behavior across different materials and contact conditions. Additionally, this work explores friction mitigation strategies, including surface treatments, coatings, and lubrication, as well as AM-enabled methods such as engineered surface textures and stress-relieving voids to enhance fatigue resistance. By integrating experimental data, numerical modeling, and tribological control strategies, this research aims to provide a systematic understanding of friction’s influence on fretting fatigue and propose advancements in predictive methodologies.

Presenting Author: Ali Fatemi The University of Memphis

Presenting Author Biography: Dr. Fatemi received his B.S. and M.S. degrees in structural analysis and design and his Ph.D. in Mechanical Engineering in 1985, all from The University of Iowa. He was on the faculty of Mechanical Engineering at Purdue University-Fort Wayne from 1985 to 1987 and on the faculty of Mechanical, Industrial and Manufacturing Engineering at the University of Toledo from 1987 to 2017 where he was a Distinguished University Professor prior to joining the University of Memphis in August 2017.

Dr. Fatemi has taught many subjects in mechanics and design. At the graduate level he has been teaching courses on fatigue of materials and structures, fracture mechanics, advanced mechanics of materials, mechanics of composite materials, and experimental mechanics. He has directed theses and dissertations of more than 50 students at the master and doctoral levels, as well as working with post-doctoral fellows. He has also been teaching short courses and seminars for academia and industry around the world.

Dr. Fatemi's primary research interests and publications involve materials mechanical behavior in general, and in fatigue and fracture mechanics in particular. He has published over 250 refereed papers dealing with fatigue and fracture, both at the basic level helping to understand fundamental fatigue damage mechanisms as well as in the applied areas facilitating applications of the knowledge learned to the design and life prediction of engineering components and structures. He has co-authored the second edition of a fatigue textbook entitled "Metal Fatigue in Engineering" published by Wiley in 2000. A list of Dr. Fatemi's publications can be found at "Google Scholar.com/citations". Dr. Fatemi has had sponsored research projects from many companies, foundations, and government agencies. The experimental Fatigue and Fracture Research Laboratory at the University of Memphis houses state of the art equipment including several servo-hydraulic testing systems.

Dr. Fatemi is a Fellow of the American Society of Mechanical Engineers (ASME), a member of the American Society for Testing and Materials (ASTM) Committee E-8 on Fatigue and Fracture, and the American Academy of Mechanics. He is on the editorial boards of the International Journal of Fatigue and the Journal of Theoretical and Applied Fracture Mechanics. He has received several awards for his research including the University of Toledo Outstanding Research Award in 2002, and the Sigma Xi/Dion Raftopoulos Award for Outstanding Research in 2008. He was awarded honorary membership in the German Association for Materials Research (DVM). He has been a member of the Scientific Committee of and a Keynote Speaker at international conferences on fatigue and fracture.

Authors:

Samira Ghadar The University of Memphis
Ali Fatemi The University of Memphis
Nam Phan Naval Air Systems Command