Fretting Wear and Fretting Fatigue


Book Description

Fretting Wear and Fretting Fatigue: Fundamental Principles and Applications takes a combined mechanics and materials approach, providing readers with a fundamental understanding of fretting phenomena, related modeling and experimentation techniques, methods for mitigation, and robust examples of practical applications across an array of engineering disciplines. Sections cover the underpinning theories of fretting wear and fretting fatigue, delve into experimentation and modeling methods, and cover a broad array of applications of fretting fatigue and fretting wear, looking at its impacts in medical implants, suspension ropes, bearings, heating exchangers, electrical connectors, and more. - Covers theoretical fundamentals, modeling and experimentation techniques, and applications of fretting wear and fatigue - Takes a combined mechanics and materials approach - Discusses the differences and similarities between fretting wear and fretting fatigue as well as combined experimental and modeling methods - Covers applications including medical implants, heat exchangers, bearings, automotive components, gas turbines, and more




Mechanics of Fretting and Fretting Fatigue


Book Description

This book, which has only one very distant forerunner authored by David A. Hills with David Nowell, represents a very big step that is the quantification of these problems and represents the twenty-five years’ worth of work which have gone on at Oxford since the first book on the subject. Fatigue (popularly ‘metal fatigue’) is the primary failure mode of all machines, engines, transmissions and indeed almost all mechanical devices. The propagation of cracks is well understood and is treated in the subject Fracture Mechanics. By contrast, the nucleation of cracks is very hard to quantify and this remains the case with so-called ‘free initiation’ and, to a lesser extent, at cracks nucleated from stress raising features. But the third form of nucleation, where cracks start from the edges of rubbing components, that is, at joints, is potentially a very much better-defined environment, and therefore, the problem is amendable to attack by applied mechanics and experiment. The contents are of value both to those embarking on research on the subject and to practitioner in industry.




Mechanics of Fretting Fatigue


Book Description

Failures of many mechanical components in service result from fatigue. The cracks which grow may either originate from some pre-existing macroscopic defect, or, if the component is of high integrity but highly stressed, a region of localized stress concentration. In turn, such concentrators may be caused by some minute defect, such as a tiny inclusion, or inadvertent machining damage. Another source of surface damage which may exist between notionally 'bonded' components is associated with minute relative motion along the interface, brought about usually be cyclic tangential loading. Such fretting damage is quite insidious, and may lead to many kinds of problems such as wear, but it is its influence on the promotion of embryo cracks with which we are concerned here. When the presence of fretting is associated with decreased fatigue performance the effect is known as fretting fatigue. Fretting fatigue is a subject drawing equally on materials science and applied mechanics, but it is the intention in this book to concentrate attention entirely on the latter aspects, in a search for the quantification of the influence of fretting on both crack nucleation and propagation. There have been very few previous texts in this area, and the present volume seeks to cover five principal areas; (a) The modelling of contact problems including partial slip under tangentialloading, which produces the surface damage. (b) The modelling of short cracks by rigorous methods which deal effectively with steep stress gradients, kinking and closure. (c) The experimental simulation of fretting fatigue.




Fretting Wear, Fretting Fatigue and Damping of Structures


Book Description

This book provides a comprehensive overview of the mechanical distinctions between fretting damage under axial or bending external forces and fretting damage under a torsional load. It emphasizes the importance of studying practical accident cases to efficiently acquire technical skills. The book is structured around the fundamental technologies of material science, tribology, and mechanics, which are vital for understanding and addressing technical issues. The author has incorporated all fretting countermeasure technologies, which were previously often sensory and empirical in nature, and repositioned them as technologies grounded in fundamental principles. The book proposes an economical approach to product operation that maintains reliability by integrating not only design technology but also maintenance practices. It delves into specific materials, such as titanium alloys and aluminum alloys, which have seen increased use for weight reduction in industries like aerospace. In this book, “Critical Distance Stress Theory” that can easily derive the fatigue limit and fatigue life of the stress singular field at the contact edge was presented. As a result, the fretting fatigue strength and life can be predicted from the same FEM stress analysis as the normal stress concentration part. And finally, introducing a novel fretting mechanical model, the book focuses on scenarios where pressure force (N) and repeated tangential force (F) are applied to two planar objects, with the tangential force being transmitted solely through friction at the contact surface. This model finds relevance in turbine blade connection structures, among other applications. The author references Asai's research example, which encompasses fretting mechanical analysis, fretting wear evaluation, fatigue assessment, and structural damping evaluation using this model.




Fretting Fatigue


Book Description

This volume includes 36 of the 40 papers presented at the symposium, and a collection of six keynote papers providing background on the subject. Topics covered include parameter effects, environmental effects, crack nucleation, material and microstructural effects, damage analysis, fracture mechanic







Fretting Fatigue


Book Description

Contains 29 contributions drawn from the Third International Symposium on Fretting Fatigue held in Nagaoka, Japan in May 2001. Sections of the volume address fretting wear and crack initiation; fretting fatigue crack and damage; life prediction; fretting fatigue parameter effects; loading condition




Introduction to Thermodynamics of Mechanical Fatigue


Book Description

Fatigue is probabilistic in nature and involves a complex spectrum of loading history with variable amplitudes and frequencies. Yet most available fatigue failure prediction methods are empirical and concentrate on very specific types of loading. Taking a different approach, Introduction to Thermodynamics of Mechanical Fatigue examines the treatment of fatigue via the principles of thermodynamics. It starts from the premise that fatigue is a dissipative process and must obey the laws of thermodynamics. In general, it can be hypothesized that mechanical degradation is a consequence of irreversible thermodynamic processes. This suggests that entropy generation offers a natural measure of degradation. An Entropic Approach to Fatigue and Degradation Drawing on recent cutting-edge research and development, the authors present a unified entropic approach to problems involving fatigue. They introduce the fundamentals of fatigue processes and explore a wide range of practical engineering applications. Fundamental Concepts and Methodologies The book reviews commonly observed failure modes, discusses how to analyze fatigue problems, and examines the deformation characteristics of a solid material subjected to fatigue loading. It also looks at how to use thermodynamics to determine the onset of fatigue failure. In addition, the book presents methodologies for improving fatigue life and for accelerated fatigue testing. Learn How to Apply the Entropic Approach to Fatigue Problems Comprehensive and well organized, this work helps readers apply powerful thermodynamics concepts to effectively treat fatigue problems at the design stage. It offers an accessible introduction to a new and exciting area of research in the field of fatigue failure analysis.