As the cof varies along the direction of motion the fretting loop given by. Some of these parameters include differing materials, relative displacement amplitudes, normal force at the fretting contact, alternating tangential force, the contact geometry, surface integrity parameters such as finish, and the environment. For example, fretting in railway axles was reported by maxwell et al. Arefin kowser, mohammad asaduzzaman chowdhury, and quazi md. Fretting loop is a hysteresis plot for coefficient of. Suresh a systematic investigation of the fretting fatigue behavior of.
Finite element simulation of fretting wearfatigue interaction in spline couplingsj. Tests were conducted at various maximum loads and normal pressures. Clickhere to see several clear photos of fretting which resulted in fatigue fracture. Fretting fatigue crack initiation and propagation behavior. The best overview of fretting fatigue tests known to the authors dates from 1994 in mechanics of fretting fatigue 2 by hills and nowell. Fretting is a special wear process that occurs at the contact area between two materials under load and subject to slight relative movement by vibration or some other force. This damage is induced under load and in the presence of repeated relative surface motion, as induced for example by vibration.
There are some features of frettingfatigue cracking that are unique. A fretting fatigue model has been implemented in comsol validation of fretting fatigue models vs. In the present chapter, the fretting corrosion mechanism is discussed in section 15. The fretting damage process is a synergistic competition among wear, corrosive and fatigue phenomena driven by both the microslip at the contact surface and. Based on continuum damage mechanics, an elastic plastic. Fretting fatigue experiments and finite element analysis were carried out. For flatonflat contact, a fretting fatigue crack is likely to nucleate at the. The damage due to fretting in air increases with increasing pressure between faying parts, increasing relative motion and increasing number of cycles. This article focuses on measures to avoid or minimize crack initiation and fretting fatigue. Ten specimens were prepared and tested to fit the sn curve. Request pdf fretting fatigue fracture this chapter deals with the investigation of contact interaction of two bodies under the conditions of fretting fatigue. Life predictionaddresses fretting fatigue life estimations, based on various approaches including fracture mechanics, notch fatigue analysis and. Fretting fatigue behavior of ti6al4v and ti10v2fe3al. From a structural standpoint, fretting can have much in.
Pdf a study of fretting fatigue in aircraft components. Several aspects of the mechanics of cracks originating at sites of fretting are considered. This projection piece reduces the local stiffness and releases the. A unified fracture mechanics approach to fretting fatigue crack. Preventing fretting fatigue in blade dovetail roots by. Pdf fretting fatigue experiment and analysis of alsi9cu2mg alloy. Fretting fatigue is the fatigue damage phenomena due to cyclic stress on the components affected by fretting and reduces the fatigue life extensively compared with non fretting fatigue. Common features of frettingfatigue cracking in steels. Fretting fatigue fatigue and fracture handbooks asm. Fretting fatigue analysis of fullscale railway axles in. Fretting fatigue crack and damagediscusses fretting fatigue crack propagation under mixed mode, based on the fracture mechanics approach.
We present in this paper a strategy to combine existing contact. Fatigue and fretting fatigue life prediction of doublelap. This work aims to investigate the fretting fatigue life and failure mode of steel q235b plates in singlelap bolted joints. Hills i mechanics of fretting fatigue 1 under these conditions, modelling of the final phase of the initiation process will be even more. Fretting can occur when repeated loading on a structure or part causes repetitive relative movement at contacting metallic surfaces. Mechanics of fretting fatigue crack formation sciencedirect. Fretting is characterized by the production of large amounts of debris consisting mostly of powdered metal oxide with some flakes of unoxidized metal. On the other hand, the minimum strengths of samples a and b differed little about 5% under lc conditions. Nevertheless, additional research on fretting fatigue crack initiation and propagation behavior is necessary in order to evaluate its fretting fatigue life more accurately. Movement can be as short as 1 micron, due to mechanical vibration can be a microscopic contact within the contact area, without gross sliding damage is hidden in contact area. Numerical estimation of fretting fatigue life of bolted. A special wear process that occurs at the contact area between two materials under load and subject to minute. In this study, crack growth tests of fretting fatigue are conducted, and the characteristics of fatigue crack initiation and propagation are analyzed on inconel 690 alloy. Fretting fatigue is the phenomenon of crack initiation and propagation from the region of stress concentration in reciprocating frictional contacts.
Fretting corrosion has been the cause of countless failures at the contact points of machinery components. The effect of fretting on fatigue performance of different microstructures for titanium alloy was studied using a highfrequency pushpull fatigue testing machine. Fretting corrosion and fretting fatigue springerlink. Fretting is a special wear process that occurs at the contact area between two. Various types of fretting pads were used in order to determine the effects of contact geometries. Download fulltext pdf download fulltext pdf on the convergence of stresses in fretting fatigue. An experimental investigation of fretting fatigue in ti. Mechanics of fretting fatigue solid mechanics and its. Fatigue and fretting fatigue are the main failure mode in bolted joints when subjected to cyclic load. Pdf on the convergence of stresses in fretting fatigue. Analysis of fretting fatigue crack initiation in a. Performing organization name and address quality and integrity design engineering center qedec department of mechanical engineering university of utah. Fretting fatigue of engineering ceramics has yet to be investigated sufficiently.
Hills department received of engineering science, university of oxford, parks road. Several of these features are illustrated in three case histories described in. Nishimura department of mechanical and system engineering, gifu university, japan abstract in this paper we present the estimation methods of fretting wear process and fretting fatigue life using this wear process. Fretting fatigue crack initiation in titanium alloy, ti. Fretting fatigue life estimations based on the critical. Sem scanning electron microscope was then employed to observe fatigue crack surfaces and identify crack initiation, crack propagation, and transient fracture zones. Important variables on fretting corrosion are discussed in section 15. The friction stress is maximum on the contact surface of the. Fretting corrosion is a practical problem because it can cause significant reductions of fatigue properties of structural elements. An experimental investigation of fretting fatigue in ti6al4v. All stages of damage evolution, from initiation to failure, are encompassed. Fretting refers to wear and sometimes corrosion damage at the asperities of contact surfaces.
The impact of material properties and surface treatments is investigated. The asm handbook on fatigue and fracture defines fretting as. It is argued that the problem may be distilled into three separate parts. From a structural standpoint, fretting can have much in common with pitting. The fretting damage process is a synergistic competition among wear, corrosive and fatigue phenomena driven by both the microslip at the contact surface and cyclic fretting contact stresses. Experimental and numerical investigations of fretting. Under pc, sample b exhibited 1025% higher frettingfatigue strength than sample a. Mechanics of fretting fatigue pdf free download kundoc. Fretting fatigue has been responsible for a large number of service failures across a wide range of applications. This paper studies the contact mechanics in a line contact during fretting fatigue conditions. Shipwaythis paper describes a finite element based method for simulating the effects of material removal,associated with fretting wear, on fretting fatigue parameters in a spline coupling. Based on continuum damage mechanics, an elasticplastic. On the mechanics of fretting fatigue sciencedirect.
However, a unified solution valid for all loading cases during fretting fatigue conditions is not available. Fretting fatigue strength and life estimation considering the fretting wear process t. Fretting wear and crack nucleationcovers the process of fretting crack nucleation under fretting wear through both detailed insitu observations and mechanical models, which included not only fracture mechanics but also interface mechanics. Furthermore, if the oxide layer that is constantly being removed by the fretting has a higher hardness than the base material, then the previously worn off oxide layer in between the two materials will. Fretting fatigue is defined as damage resulting from small magnitude 0. 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. The result shows that the strength, plain fatigue of ti6al4v titanium is.
The severity of this type of fretting can be minimized by ensuring. Fretting fatigue crack initiation mechanism in ti6al4v. Based on the existing experiment results, the fretting fatigue contact geometry of a riveted two aluminum specimen was studied using the finite. Fretting fatigue analysis of fullscale railway axles in presence of artificial micronotches. For fretting fatigue, microslipping often causes initial microcracks in the contact surfaces, which gradually propagate and eventually result in fracture failure. The grooves and pits caused by fretting reduce the fatigue strength of the material because the grooves and pits act as stress concentrators. The roughness effects on fretting fatigue of aluminium alloy also have been studied 23, especially. Astm e2789 102015 standard guide for fretting fatigue. In literature one can find numerical and analytical solutions of normal and tangential stresses for a variety of.
Fatigue loading was applied at 30 hz in a laboratory environment with the fatigue specimen loaded in fatigue and fretting applied to the specimen central section through a fretting pad made of the same material as the specimen. In literature one can find numerical and analytical solutions of normal and tangential stresses for a variety of loading cases. Finite element simulation of fretting wear fatigue. Proceedings of the 8th international symposium on fretting. Therefore, a new test rig to investigate fretting fatigue using four point bending. The fretting process may cause local metal loss and impact the initiation andor propagation of fatigue cracks. Proceedings of the 8th international symposium on fretting fatigue. Pdf an investigation was carried out in order to study the fretting fatigue behavior of an alsi9cu2mg aluminum alloy.
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