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1
Kirkpatrick, Gary W. "Fretting fatigue analysis and palliatives." Thesis, Springfield, Va. : Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA372220.
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Thesis (Degree of Naval Engineer and M.S. in Materials Science and Engineering) Massaschusetts Institute of Technology, June 1999."June 1999". Includes bibliographical references (leaves 96-100). Also available online.
2
Nowell, D. "An analysis of fretting fatigue." Thesis, University of Oxford, 1988. http://ora.ox.ac.uk/objects/uuid:61c9f75d-7c81-4280-9997-91f6e79543fb.
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This thesis describes a series of fretting fatigue experiments carried out under closely controlled conditions of partial slip. These experiments confirm the existence of a size effect whereby the fretting fatigue life of an aluminium alloy is shown to vary with contact size. The configuration chosen, of cylindrical fretting pads contacting a plane specimen is amenable to classical stress analysis and the surface tractions between the contacting bodies are derived. The effects of tension in the specimen, finite specimen thickness, differing elastic constants, and surface roughness are all investigated and incorporated into the analysis where appropriate. A technique is then developed to calculate stress intensity factors for plane cracks growing under the contact load at an arbitrary angle to the free surface. The analysis is then applied to the experimental results and three possible explanations for the size effect are proposed, based on statistical effects, crack arrest, and crack initiation. These are examined in the light of the experimental evidence and it is proposed that the variation of fatigue life with contact size is due to an increase in the amount of fretting damage above a threshold level for crack initiation. A composite parameter is chosen to characterise the severity of fretting conditions and this is shown to describe the experimental results accurately. Finally, the use of this parameter in design calculations is discussed.
3
Xu, Yangjian. "Computational analysis of fretting fatigue." Düsseldorf VDI-Verl, 2009. http://d-nb.info/996624554/04.
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Kirkpatrick, Gary W. (Gary Wayne) 1966. "Fretting fatigue analysis and palliatives." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85327.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering; and, (Nav.E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1999.Includes bibliographical references (leaves 96-100).
by Gary W. Kirkpatrick.
S.M.
Nav.E.
5
Bellecave, Johan. "Stress Gradients In Fretting Fatigue." Thesis, Cachan, Ecole normale supérieure, 2015. http://www.theses.fr/2015DENS0036/document.
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Cette thèse fait partie d’un programme de recherche international (IRG Cognac). Lancé par le motoriste SNECMA (groupe SAFRAN), ce projet regroupe l’ENS Cachan, UnB, ENSMA, CNRS, Snecma, Turbomeca et Messier Bugatti Dowti, et se concentre sur l’effet du gradient des contraintes sur endommagement par fretting fatigue. Le fretting-fatigue se réfère au processus d’endommagement localisés en bord de fuite entre deux corps en contact soumis à un chargement de fatigue. La maitrise de ce phénomène est d’une importance cruciale dans la détermination des durées de vie des disques de turbine. En bord de contact, le champ de contrainte hérité des forces de contact est maximal à la surface mais présente un fort gradient en s’éloignant du contact.Il a été montré dans cette thèse que pour l’alliage Ti-6AL-4V, les approches locales, basés sur le niveau de contrainte au points critiques ne sont pas applicable dans ces conditions. Une approche non locale, s’appuyant sur la théorie de la distance critique a donc été utilisée. En effet, des fissures courtes initiées au point critique peuvent propager jusqu’à rupture ou peuvent s’arrêter si la diminution des contraintes est suffisamment sévère. Une seconde difficulté réside dans la nature multiaxial et localement non proportionnel du chargement. Le fretting fatigue est généralement créé par la superposition d’un chargement de fatigue cyclique, d’une force normale à la surface souvent considérée constante, et d’une force cyclique tangentiel à la surface mais dont la fréquence peut être différente de celle de la fatigue.Les résultats des essais réalisés ont mis en évidence l’effet du gradient des contraintes sur la fissuration et ont étaient utilisés pour évaluer le potentiel de diffèrent critères pour le dimensionnement en fatigue des structures. La simulation du phénomène a en effet été réalisé en utilisant différente approches. La première s’appuie sur la Théorie de la distance critique et utilise un critère multiaxial. La seconde utilise l’amplitude du facteur d’intensité des contraintes, ΔK, pour prédire l’arrêt des fissures courtes. Finalement un récent modèle construit comme un critère de plasticité en pointe de fissure a été appliqué au problème de fretting fatigue. Ce critère a pour particularité de prendre en compte la contrainte T dans le développement asymptotique en pointe de fissureThis thesis is part of an international research program (IRG Cognac) initiated by the engine manufacturer SNECMA (SAFRAN group) involving ENS Cachan, UnB, ENSMA, CNRS, Snecma, Turbomeca et Messier Bugatti Dowty. The thesis focuses on the effect of a stress gradient in fretting fatigue. Fretting-fatigue refers to the damage process localized at the frontier of the contact between two contacting bodies subjected to fatigue loadings. The prediction of this phenomenon is of major importance in determining, for instance, the lifetime of fan's disc. In the vicinity of the contact front, the stress field inherited from the contact loads is maximal at the surface and displays a strong gradient from the surface. It was shown in this thesis, for a Ti-6AL-4V alloy, that local approaches, based on local stresses at the most critical point, are not appropriate to predict fretting fatigue lives. As a matter of fact, short cracks initiated at the most critical point may stop if the stress decay from the surface is strong enough or may continue their growth, up to the failure of the component, if the stress gradient from the surface is not string enough. A second difficulty is the multiaxial and non-proportional nature of the loading conditions. Fatigue-fretting stems from the combination of loads that have neither the same spatial distribution nor the same time-dependency. In fretting-fatigue tests, three loading components are considered, the fatigue loading of the component (cyclic), the normal part (assumed to be constant) and the in-plane part (cyclic) of the loads between the two contacting components. To quantify the effect of the stress gradient, tests were carried out on a fatigue testing contact bench developed at the University of Brasilia, with experimental conditions ensuring different stress gradient while keeping the maximal stress the same. Damage mechanisms were studied using post-mortem analysis and optical microscopy on the contact elements tested. The prediction of the fretting fatigue life was done using different approaches. The first one is based on the Critical Distance Method and a fatigue criterion. The second is based on a K-based short crack arrest method. Finally, a new criterion was proposed. This method considers a generalized von Mises yield criterion for the crack tip region and accounts for the T-stresses in the asymptotic LEFM development
6
Swalla, Dana Ray. "Fretting fatigue damage prediction using multiaxial fatigue criteria." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/17033.
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Kim, Kyungmok. "The investigation of fretting wear and fretting fatigue of coated systems." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432361.
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Madge, Jason John. "Numerical modelling of the effect of fretting wear on fretting fatigue." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10681/.
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This thesis reports the development of a method for predicting the fretting fatigue life of a system which takes into consideration the material removed as a result of fretting wear. The first implementation is based on a critical plane, multiaxial fatigue model and a damage accumulation framework. The model is applied to both ‘cylinder on flat’ and ‘rounded edge punch on flat’ geometries, for which experimental data from the literature is used for comparison. The method is able to predict a number of key experimentally observed phenomena, which existing approaches are unable to do. The dependence of fretting fatigue life on slip amplitude is captured demonstrating a critical range of slip amplitudes, relating to the partial slip regime, for which a minimum in life is predicted. The method is also shown to predict the occurrence of cracking at specific locations in the slip region. The method indicates that these phenomena are dependent on the relative rates of wear and fatigue damage occurring across the contact. The second implementation treats the nucleation and propagation fatigue phases separately. The fatigue model adopted above is reformulated to serve as a nucleation model, whilst the crack propagation phase is based on a fracture mechanics perspective. The method is used to study the effect of wear on both the propagation and nucleation aspects of fatigue. The method is also employed to investigate the role of fretting wear in fretting fatigue crack arrest.
9
Van, Peteghem Benjamin. "Fretting et fretting-fatigue à haute température d'alliages de titane revêtus." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961238.
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Les endommagements provoqués par le fretting sont multiples et peuvent causer de sévères disfonctionnements. Il est donc nécessaire d'étudier le fretting, en particulier dans le cas des alliages de titanes fréquemment employés dans l'aéronautique. Les endommagements générés par fretting peuvent être de l'usure, de la fissuration ou bien une combinaison des deux. La distinction entre ces deux comportements entraine régulièrement une dichotomie dans le choix des sujets traités. L'étude présentée ici fait le choix de rassembler en une seule démarche les études d'usure et de fissuration. Cette approche permet d'avoir une vision d'ensemble du comportement en fretting et fretting-fatigue d'un contact aube-disque dans un compresseur haute pression. Afin de respecter les contraintes industrielles, l'étude est réalisée à haute température (450°C) avec un contact plan sur plan revêtu. Pour réaliser cette étude, un dispositif expérimental original a été mis en place et validé. Les premiers résultats tribologiques montrent un effet majeur de la pression de contact sur le comportement tribologique de l'interface. Le coefficient de frottement du traitement de surface étudié diminue quand la pression de contact augmente. Une hypothèse d'expulsion du lubrifiant solide inclus dans le dépôt est proposée pour expliquer ce phénomène. Les résultats d'usure et notamment les analyses physicochimiques montrent un comportement sacrificiel du dépôt qui est usé préférentiellement au contre-corps. Cette caractéristique est bénéfique car dans l'application industrielle le contre-corps (le disque) doit être protégé en priorité par rapport à la pièce revêtue (l'aube). Les résultats d'usure dans la configuration industrielle sont complétés par une étude plus fondamentale mettant en évidence l'influence de la fréquence et du cycle de chargement du contact. La morphologie des traces d'usure est modifiée par ces deux facteurs, et le taux d'usure énergétique est également modifié. L'étude de la fissuration est menée en fretting simple et en fretting-fatigue. La fissuration du contre-corps non revêtu est modifiée par l'application d'un dépôt sur le poinçon revêtu. L'effet est principalement observable sur la longueur maximale de fissure, qui est divisée par deux dans le cas revêtu. Les résultats en fretting-fatigue sont également modifiés par la présence du revêtement, dont l'effet est plus présent pour les grands nombre de cycles. Enfin, une représentation des résultats sous forme de diagramme polaire normalisé est proposée afin de donner une image claire de l'ensemble des performances du dépôt.
10
Rajasekaran, Ramesh. "Analysis of dovetails for fretting fatigue." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410672.
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Hooper, J. "Fretting fatigue under variable amplitude loading." Thesis, Cranfield University, 2003. http://dspace.lib.cranfield.ac.uk/handle/1826/11046.
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Fretting fatigue is a major concern in the design of engineering components that will be
subjected to clamping pressures whilst operating in a vibrational environment. The type
of loading environment generated in these applications is generally of a variable
amplitude nature. Therefore it is important for engineers to understand how such
loading affects the severity of fretting fatigue. In the absence of this understanding,
engineering designers are left to apply simplistic plain fatigue life prediction rules, such
as Miners linear damage law, to try to estimate the damage generated from a particular
loading history.
In order to try to establish a baseline for the understanding of fretting fatigue under
variable amplitude loading, a structured series of CAL and V AL tests were designed
and carried out. The aim of the CAL tests was to characterise the fretting fatigue test rig
(designed by the author) so that an experimental foundation could be developed, upon
which the fretting fatigue study was based. A structured investigation into the effects on
fretting fatigue of applying various specifically designed loading histories was carried
out and some very distinct relationships between the applied loading spectra and fretting
fatigue life were found. For the application of overloads it was observed that overload
size, overload application interval and the number of overloads in each application all
had a sizeable effect on the severity of fretting. Two-level, three-level and five-level
block loading tests were also investigated and numerous loading history dependent
results were obtained.
The applicability of Miners law to fretting fatigue was assessed. Combining Miners law
with well-defined CAL stress-life results gave reasonable predictions for all of the V AL
fretting fatigue tests carried out, with damage summations at failure ranging from 0.64
(non-conservative) to 3.19 (conservative). However, a more detailed investigation into
the relationship between fretting fatigue lives and damage summations due to the
individual loading levels highlighted that the assumption of linear damage may not be
applicable to fretting fatigue, especially during crack initiation and early crack growth.
A hypothesis was proposed to explain the fretting fatigue life and Miner damage results
observed for the different loading spectra, and reasonable success was obtained for tests
where the Miners law proved conservative (in 27 of 36 tests), although the hypothesis
was not able to explain the non-conservative results obtained in the other nine tests.
12
Hooper, Jeremy. "Fretting fatigue under variable amplitude loading." Thesis, Cranfield University, 2003. http://dspace.lib.cranfield.ac.uk/handle/1826/11046.
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Fretting fatigue is a major concern in the design of engineering components that will be subjected to clamping pressures whilst operating in a vibrational environment. The type of loading environment generated in these applications is generally of a variable amplitude nature. Therefore it is important for engineers to understand how such loading affects the severity of fretting fatigue. In the absence of this understanding, engineering designers are left to apply simplistic plain fatigue life prediction rules, such as Miners linear damage law, to try to estimate the damage generated from a particular loading history. In order to try to establish a baseline for the understanding of fretting fatigue under variable amplitude loading, a structured series of CAL and V AL tests were designed and carried out. The aim of the CAL tests was to characterise the fretting fatigue test rig (designed by the author) so that an experimental foundation could be developed, upon which the fretting fatigue study was based. A structured investigation into the effects on fretting fatigue of applying various specifically designed loading histories was carried out and some very distinct relationships between the applied loading spectra and fretting fatigue life were found. For the application of overloads it was observed that overload size, overload application interval and the number of overloads in each application all had a sizeable effect on the severity of fretting. Two-level, three-level and five-level block loading tests were also investigated and numerous loading history dependent results were obtained. The applicability of Miners law to fretting fatigue was assessed. Combining Miners law with well-defined CAL stress-life results gave reasonable predictions for all of the V AL fretting fatigue tests carried out, with damage summations at failure ranging from 0.64 (non-conservative) to 3.19 (conservative). However, a more detailed investigation into the relationship between fretting fatigue lives and damage summations due to the individual loading levels highlighted that the assumption of linear damage may not be applicable to fretting fatigue, especially during crack initiation and early crack growth. A hypothesis was proposed to explain the fretting fatigue life and Miner damage results observed for the different loading spectra, and reasonable success was obtained for tests where the Miners law proved conservative (in 27 of 36 tests), although the hypothesis was not able to explain the non-conservative results obtained in the other nine tests.
13
Cadario, Alessandro. "On fretting fatigue with a spherical indenter /." Stockholm : Department of Solid Mechanics, Royal Institute of Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1818.
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Mugadu, A. E. B. "Studies in fretting fatigue of complete contacts." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411156.
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Hu, Qinghua. "Fretting wear and fretting fatigue behaviour of a SiC particle reinforced aluminium alloy." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326537.
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Perier, Virginie. "Etude de l'influence des conditions environnementales sur le comportement en fretting, fatigue et fretting-fatigue des câbles du génie civil." Phd thesis, ECOLE CENTRALE DE LYON, 2010. http://tel.archives-ouvertes.fr/tel-00969179.
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Les câbles d'ouvrages d'art sont sujets à deux principales causes d'endommagement :le fretting-fatigue et la corrosion. Ces dernières peuvent s'activer simultanément sur une même zone de câble et interargir en entraînant la rupture prématurée de ls constitutifs des câbles. Un dispositif expérimental, le banc de fretting-fatigue, permet de reproduire, à l'échelle du fil, les conditions de sollicitation des câbles de ponts à haubans ou de ponts suspendus.Une étude de fatigue et de fretting-fatigue en milieu corrosif a été menée. Elle a consisté à étudier l'endommagement de fils soumis à du fretting-fatigue dans une solution de chlorure de sodium. Dans ce cas, les durées de vie ne sont que faiblement modifiées. Deux phases ont alors été dissociées : une phase d'amorçage et une phase de propagation des fissures. Dans les conditions d'essais retenues, le fretting est prépondérant dans la phase d'amorçage de la fissure. Il a été choisi d'amorcer une fissure en fretting-fatigue puis de la faire propager en fatigue-corrosion. Quelques solutions ont été testées. La propagation dans une solution de thiocyanate d'ammonium montre une réduction significative de la durée de vie de l'éprouvette. Cette étude va se poursuivre en accélérant les phénomènes corrosifs grâce à des méthodes électrochimiques (imposition d'un potentiel ou d'un courant).
17
Araujo, cardoso Raphael. "Études numériques sur la modélisation du fretting fatigue." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN004/document.
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Ce travail a été entrepris dans le cadre d’une coopération internationale entre l’Université de Brasilia, l’Agence spatiale brésilienne (AEB), l’ENS Paris-Saclay et le groupe SAFRAN. L’objet principal de cette coopération est l’étude du fretting-fatigue, problème de contact associé à des charges de fatigue qui réduisent considérablement la durée de vie des composants en raison de la concentration élevée de contraintes, de l’usure et des conditions de chargement non proportionnelles. En ce qui concerne les coûts de calcul élevés impliqués dans l’évaluation des applications industrielles, l’un des objectifs de ce travail est d’améliorer les performances des simulations de frettage utilisant une approche d’enrichissement. L'idée est de tirer parti du fait que les champs mécaniques autour des bords de contact dans des configurations de contact cylindriques dans des conditions de frottement sont similaires à ceux trouvés près du fond de fissure dans les problèmes de mécanique de rupture élastique linéaire. Cette similitude rend attrayante l’idée d’enrichir les simulations de frettage par éléments finis via le framework X-FEM, ce qui nous permet de travailler avec des maillages plus grossiers tout en conservant une bonne précision. Comme nous le montrerons dans ce travail, il est possible de travailler avec des maillages jusqu'à 10 fois plus grossiers que si une méthode par élements finis classique était utilisée, permettant une forte amélioration des performances de calcul.Ce travail étudiera également l’influence de la prise en compte des effets de l’usure dans la prévision de la durée de vie en fatigue. Par conséquent, des simulations par éléments finis du fretting-fatigue ont été effectuées en tenant compte de la mise à jour de la géométrie due à l'enlèvement de matière et les résultats ont été comparés aux données expérimentales et aux simulations par éléments finis dans lesquels les effets de l'usure ont été négligés (stratégie simplificatrice généralement adoptée pour évaluer les problèmes de fatigue de frottement). Les critères de fatigue multiaxiaux conventionnels associés à la théorie des distances critiques ont été utilisés pour prédire la vie. Les résultats ont montré que, pour les données évaluées ici, lorsque des essais de fretting-fatigue ont été menés sur un alliage Ti-6Al-4V dans des conditions de glissement partiel, considérer les effets de l'usure pourraient augmenter légèrement la précision des prévisions de durée de vie. Cependant, cette amélioration n’est peut-être pas digne d’intérêt si nous prenons en compte les coûts de calcul élevés dans les analyses d’usureThis work has been undertaken in the context of an international research cooperation between the University of Brasilia, the Brazilian Space Agency (AEB), the ENS Paris-Saclay and the SAFRAN group. The main subject of this cooperation is the investigation of fretting fatigue, which is a contact problem in conjunction with fatigue loads responsible for reducing considerably components’ fatigue life due to the high stress concentration, wear and non-proportional loading conditions involved in such problems. Regarding the high computational costs involved when assessing industrial applications, one of the aims of this work is to improve the performance of fretting simulations making use of an enrichment approach. The idea is to take advantage of the fact that the mechanical fields around the contact edges in cylindrical contact configurations under fretting conditions are similar to the ones found close to the crack tip in linear elastic fracture mechanics problems. This similarity makes attractive the idea of enriching finite element fretting simulations through the X-FEM framework, which enables us to work with coarser meshes while keeping a good accuracy. As it will be shown in this work, it is possible to work with meshes up to 10 times coarser than it should be if a conventional FE method was used allowing a strong improvement of the computational performances.This work will also investigate the influence of considering wear effects in the prediction of fretting fatigue lives. Therefore, fretting fatigue FE simulations have been carried considering the geometry update due to the material removal and results were compared to both experimental data and FE simulations where wear effects were neglected (simplifying strategy usually adopted when evaluating fretting fatigue problems). Conventional multiaxial fatigue criteria in association with the Theory of Critical Distances have been used in order to predict life. Results have shown that, for the data here assessed, where fretting fatigue tests were conducted on a Ti-6Al-4V alloy under partial slip conditions, considering wear effects might slightly increase the accuracy of life predictions. However, this slight improvement may not be worthwhile regarding the increase in the computational cost when compared to standard approaches where wear is neglected
18
Wallace, Jon Michael. "Fretting fatigue crack nucleation in Ti-6A1-4V." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17266.
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Araujo, Jose Alexander. "On the initiation and arrest fretting fatigue cracks." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342243.
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Smallwood, Russell. "Fretting fatigue of steel roping wire in seawater." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328387.
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Birch, Paul R. (Paul Robert) 1974. "A study of fretting fatigue in aircraft components." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9577.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1998.Includes bibliographical references (p. 145-152).
This thesis presents theoretical, computational, and experimental approaches to the problem of fretting fatigue in materials systems relevant to aircraft components. The basic contact mechanics for fretting fatigue in a sphere-plane contact geometry are reviewed. Various elastic criteria for predicting fretting failure are discussed; selected fretting maps created from one of these - the modified Crossland criterion -- are presented. Fail/no-fail predictions based on these maps have verified trends observed in experimental work performed on Al 7075-T6 specimens. A three-dimensional finite element model of sphere-plane fretting contact is reviewed. This model has been used to model elastic and elastoplastic fretting contact. The evolution of tangential loads coincident with plastic flow has been simulated, as well as the accumulation of equivalent plastic strains for these fretting conditions. This information may be used to predict the life of components subject to fretting contact high cycle fatigue (HCF) via a Coffin-Manson type relation. Design and construction of an apparatus for performing quantitative fretting experiments are described, and results of early tests performed on 7075-T6 aluminum alloys are presented. These experiments validate the proper operation of the experimental apparatus. Finally, basic principles of fracture mechanics and the limitations of applying traditional linear elastic fracture mechanics (LEFM) to fretting fatigue are discussed. The new crack analogue concept of Giannakopoulos et al. is reviewed as a means of uniting LEFM and fretting contact mechanics to achieve a life prediction scheme for components subject to HCF that is superior to the modified Goodman diagram approach currently employed by the US Air Force.
by Paul R. Birch.
S.M.
22
Pannemaecker, Alix de. "Etude du phénomène d'arrêt de propagation des fissures au travers d'un couplage multi-échelles fretting, fretting fatigue et essai fatigue C(T)." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0010/document.
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De nombreuses structures aéronautiques telles que les contacts aube/disque, rivet/tôle, assemblages frettés ou boulonnés subissent des endommagements de fretting fatigue dus à des sollicitations vibratoires. Ces sollicitations, qui combinent des chargements de contact de fretting (micro déplacements alternés) et de fatigue, peuvent induire des phénomènes de fissuration. L’objectif de cette thèse est d’identifier les mécanismes de propagation et d’arrêt de fissuration pour différentes configurations, impliquant des chargements de fretting et de fatigue. Différents aspects seront étudiés : - Les essais de fretting simple, fretting fatigue et fatigue seront corrélés de manière à mesurer certaines propriétés mécaniques de matériaux. Dans cette démarche, une méthode inverse permettant l’identification du seuil d’arrêt de propagation des fissures longues et courtes en fatigue à partir d’essais de fretting simple et fretting fatigue est introduite. - L’effet du rapport de charge est pris en compte afin de quantifier la fermeture de fissure pour les essais de fretting et fretting fatigue. Un nouveau modèle de fermeture sera proposé. - L’effet d’échelle est étudié grâce au développement d’une nouvelle machine de fretting fatigue permettant le suivi in situ des propagations de fissures sur des éprouvettes millimétriques. Le comportement des fissures courtes en fretting pendant un essai de fretting fatigue a été observé pour la première fois. L’idée principale de ce travail est de considérer que lors d’un essai en fretting simple, une condition d’arrêt de propagation est systématiquement atteinte. Les facteurs d’intensités de contraintes seuils en fatigue peuvent ainsi être extraits par une méthode inverse à partir des essais de fretting. La méthodologie adoptée consiste à mesurer la longueur de fissure maximale obtenue lors d’un essai de fretting correspondant à une condition d’arrêt de propagation. En jouant sur les chargements de fretting, les domaine des fissures courtes et longues sont étudiés. Pour chaque condition d’arrêt, le facteur d’intensité de contraintes seuil correspondant est calculé. Enfin, en traçant l’évolution de ce dernier en fonction de la longueur de fissure, une description complète des seuils d’arrêt de fissuration en fatigue peut être obtenue. Cette méthodologie est appliquée sur plusieurs configurations de fretting simple et est étendue aux essais de fretting fatigue. Ainsi une large gamme de rapports de charge peut être étudiée. Des essais conventionnels de fatigue propagation sur éprouvettes C(T) ont été réalisés de manière à valider complètement la démarche d’identification inverse des conditions d’arrêt de fissuration. Le manuscrit est divisé en six chapitres adoptant une évolution linéaire. Le chapitre 1 traite d’une revue bibliographique concernant la propagation des fissures courtes et longues en fatigue dans les matériaux métalliques, introduisant les phénomènes de fermeture. L’analyse est étendue à la propagation des fissures en fretting et fretting fatigue. Le chapitre 2 présente l’ensemble des techniques et méthodes expérimentales utilisées au cours de ce travail. Une analyse numérique et la méthode inverse d’identification des conditions d’arrêt de propagation sont introduites dans le chapitre 3. Les chapitres suivants traitent les différents résultats obtenus. Le chapitre 4 présente les essais de fretting simples menés sur différents matériaux métalliques. Une corrélation entre les conditions d’arrêt de fretting simple avec celles de fissures longues en fatigue est obtenue pour rapports de charge négatifs. Cette analyse est étendue aux rapports de charge positifs au chapitre 5 en couplant les essais de fretting simple, fretting précontraints et essais de fatigue C(T). Enfin, les effets d’échelle et la cinétique de propagation des fissures de fretting fatigue sont étudiés au chapitre 6Aircraft structures such as blade/disk, rivet/sheet and fretted or bolted assembly contacts are subjected to fatigue fretting damage caused by vibratory loads. These loads combining fretting (alternating micro displacements) and fatigue contact loading can induce cracks. The objective of this thesis is to identify the propagation and crack arrest mechanisms for different configurations involving fretting and fatigue loads. Various aspects will be studied : - Simple fretting, fatigue fretting and fatigue tests will be correlated in a way to measure some material mechanical properties. A reverse approach allowing to identify the long and short fatigue crack propagation thresholds from simple fretting and fretting fatigue will be introduced. - A new closure model taking into account the effect of loading ratio on crack closure in fretting and fretting fatigue tests will be proposed. - The scaling effect will be studied thanks to the development of a new fretting fatigue machine allowing for in-situ monitoring of the propagation of small scale cracks. The behavior of fretting short cracks has been observed for the first time in a fretting fatigue test. The main idea behind the current work is the consideration that for a simple fretting test, the crack will always lead to a crack propagation arrest condition. Threshold stress intensity factors can thus be extracted from fretting tests using a reverse method. The methodology used consists in measuring the longest fretting crack corresponding to a crack propagation arrest condition. Short and long crack regimes are studied by varying fretting loads and geometries. The corresponding threshold stress intensity factor is calculated for each arrest condition. A complete description of fatigue crack arrest thresholds can be obtained from a plot depicting the evolution of the stress intensity factor range as a function of crack length. This methodology has been applied on multiple simple fretting configurations and was extended to fretting fatigue tests allowing to study a large range of loading ratios. Conventional fatigue crack propagation tests were carried out on C(T) specimens in order to validate the reverse method used for crack arrest conditions. The present thesis is divided into six main chapters. Chapter 1 provides a complete literature review on short and long crack propagation in metallic materials introducing crack closure. It provides a treatment for both fretting and fretting fatigue including a comparative analysis. Chapter 2 provides an overview of the different techniques and methodologies used as part of this research project. The reverse method used for the identification of crack propagation arrest conditions as well as a numerical analysis are presented in Chapter 3. The following Chapters provide a treatment of the various results obtained. Chapter 4 focuses on simple fretting tests carried out on different metallic materials. A correlation between simple fretting and long fatigue crack arrest conditions was obtained for negative loading ratios. This analysis is extended to positive loading ratios in Chapter 5 combining simple fretting, prestressed fretting and C(T) fatigue tests. Finally, scaling effects and fretting fatigue crack propagation kinetics are studied in Chapter 6
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Fair, G. H. "The effect of shot peening on fatigue and fretting-fatigue of aluminium alloys." Thesis, University of Nottingham, 1988. http://eprints.nottingham.ac.uk/12723/.
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Plain-fatigue and fretting-fatigue tests have been carried out on the two peak-aged, high-strength aluminium alloys, 7010 and 8090, in the unpeened and shot peened conditions. Shot peening produced a highly deformed surface containing many deep dimples and folds from which fatigue cracks rapidly initiated. Although initiation was early, propagation through the peened surface layers was retarded by the residual compressive stresses introduced by the peening treatment; this retardation being greatest at a depth corresponding to that of the peak residual compressive stress. Shot peening improved the plain-fatigue properties of the 7010 alloy at high applied stresses and this improvement decreased as the applied stress was reduced. A reversed trend was observed in the 8090 alloy with shot peening being beneficial to the fatigue properties at low applied stresses and detrimental at high applied stresses. The poor resistance of the 7010 alloy to fretting-fatigue was eliminated by shot peening and this was again attributed to the residual compressive stress induced by the peening treatment. Since the 8090 alloy in the unpeened condition is relatively insensitive to the effects of fretting, shot peening resulted in only a minor improvement in the fretting-fatigue behaviour of this alloy.
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Grossmann, Christoph. "Fretting fatigue of shape optimised polygon-shaft-hub connections." [S.l.] : [s.n.], 2006. http://opus.kobv.de/tuberlin/volltexte/2007/1519.
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Houghton, Dean. "Representative fretting fatigue testing and prediction for splined couplings." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/11013/.
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Spline couplings are a compact and efficient means for transferring torque between shafts in gas turbine aeroengines. With competition in the aerospace market and the need to reduce fuel burn from the flight carriers, there is an ever-present requirement for enhanced performance. Spline couplings are complex components that can fail from a variety of mechanisms, and are susceptible to fretting wear and fretting fatigue (FF). Due to the expensive nature of full-scale testing, this thesis investigates the use of the representative specimen (RS) concept for predicting fretting-induced damage between spline teeth. A combined experimental and computational RS methodology is developed, using a uniaxial representative specimen (URS) and a multiaxial representative specimen (MRS). The URS test rig simulates spline torque and axial loads from the overall flight cycle and associated damage. The MRS simulates the combination of the same major loads, with the addition of high-cycle bending loads from in-flight fluctuations. The URS was successfully employed for experimental characterisation of a range of spline material combinations, including inference of the coefficient-of-friction. The MRS successfully characterised the multiaxial FF behaviour of the current material of choice for triple-spool gas turbine couplings. A finite element-based total fatigue life (crack nucleation and propagation) capability was successfully validated for the MRS and URS. A global sub-modelling technique was employed, whereby a critical-plane Smith-Watson-Topper (SWT) fatigue parameter predicted crack nucleation, an El Haddad approach predicted short crack growth and a weighted function approach predicted long crack growth. A novel FF damage parameter, Dfret, was also implemented to incorporate the combined effects of relative slip and surface shear traction, in conjunction with the SWT parameter, for life prediction. The required material constants were obtained and captured the measured effect of relative slip on a titanium alloy and the measured effect of contact size on an aluminium alloy.
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Thaitirarot, Anothai. "Studies in partial slip contacts applied to fretting fatigue." Thesis, University of Oxford, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597103.
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Detailed analysis of aU the fretting fatigue test results available in the literature is carried out by employing refined asymptotic solutions. Several different criteria are used and it is shown that two give an improvement over stress-based criteria. These procedures provide a practical method for both designing against fretting fatigue failure and quantifying the nucleation time when fretting is unavoidable. The reduced stiffness method is developed together with the evolutionary algorithm which is the direct implementation of the Signorini and Coulomb friction contact inequalities. This method is capable of solving two dimensional frictional contact problems in significantly less time and is more accurately than a traditional FE approach. In addition, algorithms for determining shakedown limit of coupled contacts have also been developed. A problem of a plane receding contact was considered where a strip is pressed against an elastically similar half-plane by normal pressure extending along the strip surface but stopping short of the end. These phenomena are analysed, together with the behaviour of the system when the pressure is removed. Interfacial characteristics of a lap joint formed using friction grip bolts is also considered as these produce a receding contact. The joints consist of two elastically similar laps pressed in contact by a constant normal force and subject to oscillatory bulk load at the free end of the laps. Bulk load applied at the free ends causes a smooth change in the size of contact and the development of the slip zones. The trend of energy dissipation with the extent of contact and magnitude of remote tension, at various friction coefficients, has been found. Lastly, axisymmetric receding contact between a circular elastic disc pressed against a half-space has been studied. The disc is first subjected to normal pressure followed by torsion. Normal pressure alone causes a contact interface to separate, if the loaded area is sufficiently small. Torsion is subsequently appl ied which causes a change in the size of contact and has a significant effect on the direction of the resultant slip displacement and the stick/slip boundaries. I
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Banerjee, Nina. "The characterisation of fretting fatigue in gas turbine engines." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526934.
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Takeuchi, M. "Fretting and fatigue of a roping steel in seawater." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384690.
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KOENEN, ALAIN. "Etude du fretting-fatigue du ta6v en ambiance cryotechnique." Paris, ENSAM, 1995. http://www.theses.fr/1995ENAM0044.
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Le fretting apparait dans les surfaces en contact qui sont soumises a de faibles mouvements relatifs. En environnement cryotechnique, la fragilite des materiaux et l'adhesion des surfaces tendent a augmenter. Un modele, base sur les theories de hetz (contact statique), de mindlin (glissement preliminaire), de goodman et hamilton (glissement total) et prenant en compte l'etat des contraintes internes du materiau, a ete elabore pour decrire le champ de contraintes induit dans les couches superficielles. Les modifications du materiau sous contraintes sont prises en compte par l'utilisation de la loi de comportement elastoplastique de prager. L'endurance est caracterisee par le critere de fatique multiaxial de dang-van. Ce modele a ete valide pour le ta6v par des tests en ambiance cryotechnique effectues sur un appareil original qui permet d'appliquer independamment les contraintes volumiques des contraintes surfaciques. Ce dispositif permet en outre d'effectuer des essais de fretting-fatigue dans un domaine de l'espace des contraintes inaccessible auparavant. Les resultats experimentaux montrent une bonne correlation avec le modele. Les fissures apparaissent dans les regions definies par le modele theorique et avec l'orientation prevue. Le modele permet de predire la duree de vie en fretting-fatigue d'un contact soumis a des vibrations. En ce qui concerne les empreintes, celles obtenues par la simulation correspondent tant quantitativement que qualitativement a celles obtenues pendant les tests de validation. Elles ont globalement trois regions distinctes: (i) un cercle central plus ou moins deforme selon l'importance des contraintes appliquees, (ii) un anneau de glissement du aux microglissements de mindlin dans lequel apparaissent les degradations tribologiques, et (iii) de contact des deformations plastiques sur le contour de l'aire materialisees par un bourrelet de plastification
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Edwards, Rachel Elizabeth Edwards. "A study of shot peening effects on fretting fatigue." Thesis, University of Sheffield, 2008. http://etheses.whiterose.ac.uk/6118/.
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The high clamping forces in lap-joints in the body and wings of an aircraft result in fretting fatigue damage at the contacting surfaces. Shot peening may provide an efficient technique to delay or eliminate fretting fatigue failures. In this study, the fretting fatigue behaviour of unpeened and peened aluminium alloy 2024 T351 in flat-on-flat contact with rectangular bridge pads of aluminium alloy 2024 T351 was investigated and compared with results from previous research where steel pads were used. Contact normal pressure was maintained at a constant value during the tests while the axial load was cyclic with a stress ratio of -1 and a sinusoidal waveform of 20 Hz. The friction force acting over the contact area was measured by strain gauges mounted on the bridges. There was a considerable reduction in fatigue strength due to fretting, although improved performance for the peened condition. In all cases, fretting fatigue life was found to decrease with an increase in the normal pressure, up to a critical value of normal pressure. Above this critical value, a further increase in normal pressure tended to increase fretting fatigue life. This behaviour was observed at three different axial stresses and indicates a changed sensitivity to pressure for the fatigue damage mechanism. In order to distinguish and quantify the parameters that control such a phenomenon, both an experimental and an analytical methodology have been utilised. Fretting fatigue life was investigated in terms of the contact region and the specific roles of friction, crack growth and surface modification. The test data was used to develop and assess a fracture mechanics model based on the mechanics of the fretting fatigue process, constructed to predict fretting fatigue life. Components of friction stress estimated from surface roughness profiles, axial stress and normal stress were combined to account for the biaxiality of the loading and the benefits of shot peening were modelled by incorporating the effect of a residual stress.
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Arnaud, Pierre. "Etude expérimentale et numérique de l'usure et de son influence sur les mécanismes de fissuration en fretting et fretting fatigue." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC040/document.
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Ce travail de recherche se concentre sur la compréhension de l’usure du Ti-6Al-4V et la compétition entre l’usure et les mécanismes de fissuration sous sollicitations de fretting et fretting fatigue. Il existe de nombreuses applications où le fretting et le fretting fatigue sont les causes de rupture de système, on pourra citer les turboréacteurs d’avions ou encore les axes de train. Les sollicitations cycliques dues au fonctionnement des systèmes produisent des micro-déplacements entre les pièces, typiques du fretting. Ces travaux se concentrent sur l’usure, la prise en compte des débris d’usure dans l’interface et leurs influences sur l’amorçage et la propagation des fissures. Pour répondre à ce problème, des études expérimentales et numériques ont été menées en parallèle.Dans un premier temps, une étude numérique et expérimentale sur la compétition entre usure et amorçage a été réalisée sur le Ti-6Al-4V. Deux configurations de contact ont été étudiées, cylindre/plan et poinçon/plan. L’étude du poinçon/plan a mis en évidence la nécessité de prendre en compte la rotation du contact dans la prévision des phénomènes d’amorçage. Une méthodologie basée sur le suivi de marqueurs a permis de mesurer expérimentalement la micro-rotation entre les échantillons en contact. L’incorporation de cette rotation dans les simulations numériques a permis de mettre en évidence son influence sur les phénomènes de fissuration. Ainsi une bonne simulation des phénomènes compétitifs entre l’usure et l’amorçage de fissure a pu être réalisée et des cartes de fretting ont été déterminées. Ces cartes présentent les domaines d’endommagement en fonction des conditions de sollicitation d’un contact.Cette première partie a mis en évidence que l’usure n’était pas simulée avec exactitude. L’usure est dépendante des conditions d’essais, en d’autres termes, sa cinétique n’est pas constante quelles que soit les sollicitations. Pour mieux comprendre les mécanismes mis en jeu dans le contact homogène du Ti-6Al-4V, une étude paramétrique a été menée et met en évidence 2 mécanismes principaux d’usure, l’abrasion et l’adhésion. Ces deux mécanismes ont été associés, à l’aide d’analyses MEB, respectivement aux phénomènes d’oxydation des surfaces et aux transferts métalliques interfaciales. Une vitesse d’usure distincte est associée à chacun des mécanismes et une loi globale prenant en compte tous les paramètres d’essais étudiés est proposée. Cependant, l’observation des traces d’usure expérimentales a montré la nécessité de prendre en compte les débris dans l’interface pour pouvoir simuler les profils d’usure. Ces derniers ont un effet de concentrateur de contrainte au centre du contact, ceci tend à augmenter la profondeur d’usure et à réduire l’extension latérale du contact. Un algorithme est proposé afin de pouvoir ajouter les débris dans les simulations d’usure et permet d’obtenir des profils d’usure avec une erreur de moins de 10%.Finalement, à l’aide du modèle complet d’usure avec les débris et de fissuration, la prévision des durées de vie en fretting fatigue a pu être réalisé. Nous montrons que la méthode développée permet d’estimer de manière adéquate la réponse en fretting fatigue d’un panel varié de conditions de chargements constants. Ainsi, la carte de fretting fatigue est établie, Cette carte donne, pour un contact donné, les domaines d’amorçage, de rupture et d’activation de l’usure en fonction des chargements macroscopiques de fretting et de fatigue, est établieThis research work focuses on the comprehension of the Ti-6Al-4V wear and the competition between wear and crack processes under fretting and fretting-fatigue solicitations. There are many applications where fretting and fretting fatigue cause system failure, such as aircraft engines or train shafts. The cyclic solicitations, due to the system functioning, produce micro-displacements between parts, which are typical of fretting. Here, we are focusing on wear, taking into account debris layers in the contact interface and their effects on crack nucleation and propagation. To answer this problem, experimental and numerical studies have been carried out.First, an experimental and numerical approach on the competition between wear and crack nucleation was performed on Ti-6Al-4V. Two contact configurations were studied, cylinder/plane and punch/pane. The punch/plane study showed the necessity of taking into account the contact rotation in the crack nucleation prediction. A methodology, based on the markers tracking, allows us to measure experimentally the micro-rotation between the two bodies in contact. The incorporated rotation in the numerical simulations confirms its influence on the crack nucleation. Hence, good simulations of competitive phenomena could be performed, and fretting maps were drawn. Fretting maps introduce damage domains as a function of solicitation conditions of the contact.This previous part has shown that wear was not well simulated. Wear depends on test conditions, in other words, its rate is not constant whatever the solicitations. To better understand the mechanisms involved in the homogeneous contact of Ti-6Al-4V, a parametric test campaign was led. This work, confirmed by SEM analysis, showed 2 principal wear mechanisms, respectively oxidation and metallic transfer between surfaces. A distinct wear rate can be related to each mechanism, thus a global law taking into account all test parameters is proposed. Nevertheless, the observed experimental wear scar demonstrates the necessity to take into account the debris layer in the contact interface in order to simulate wear profiles. These layers have a concentrator effect on stresses in the inner part of the contact, resulting in an increase of wear depth and a reduction of lateral contact extension. A new algorithm is proposed to add debris layer in the wear simulation and enables us to predict simulated wear profiles with an error below 10 %.Finally, helped by the global model with wear, debris layer and crack process, the lifetime can be predicted in fretting fatigue. We show that the developed methods allow adequate estimation of the fretting fatigue cracking response for a various panel of constant loadings. Hence, the fretting fatigue map is established. The map describes, for a given contact, the cracking nucleation domain, failure domain and activation of wear domain as a function of macroscopic fretting and fatigue loadings
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Fouvry, Siegfried. "Etude quantitative des dégradations en fretting." Ecully, Ecole centrale de Lyon, 1997. http://www.theses.fr/1997ECDL0004.
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Les degradations observees dans les contrats soumis a des sollicitations de fretting apparaissent sous differentes formes en fonction des conditions de sollicitation. Fondee sur l'analyse elastique du contact sphere-plan, cette etude a pour objectif de quantifier les trois aspects que sont : la condition de glissement, l'amorcage de fissures en glissement partiel et l'usure par formation de debris pour les grandes amplitudes de glissement. On montre que la condition de glissement peut etre decrite a partir de trois variables a, b, c qui permettent de definir la transition entre glissement partiel et glissement total. La condition d'amorcage a grand nombre de cycles, etudiee en glissement partiel, depend du comportement du materiau. Pour un acier presentant un ecrouissage du type isotrope (30ncd16), le critere de dang van permet de quantifier le risque d'amorcage dans le contact si l'on tient compte du coefficient de frottement local dans l'anneau de glissement et de l'effet d'echelle. Pour les aciers fortement allies, fragiles (sc6-5-2), il importe de tenir compte des micro-carbures presents dans l'acier et d'associer la condition de fissuration a un seuil de propagation. L'usure par formation de debris en grands debattements est etudiee en associant la quantite de matiere usee a l'energie interfaciale dissipee. L'analyse globale est affinee par une description locale de l'energie dissipee dans le contact. On introduit des coefficients energetiques d'usure qui montrent une cinetique de degradation de l'acier sc6-5-2 de 9 a 10 fois superieure a celle du depot tin.
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Lévesque, Frédéric. "Analyse de la fatigue par petits débattements (fretting fatigue) de fils d'un conducteur électrique." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26314/26314.pdf.
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Le phénomène de fatigue par petits débattements est tributaire des conditions de contact où il se produit. Dépendamment de ces conditions, des contraintes ainsi que des microglissements prennent forme. Dans le cas du contact entre le berceau d'une pince de suspension et un fil de conducteur électrique, la fatigue par petits débattements est observable près du dernier point de contact (DPC) entre les deux corps. Une étude en deux parties des conditions de contact en cette zone a eu lieu.
En premier lieu, des mesures de déformations ont été prises sur les fils les plus susceptibles de rupturer lors d'essais de fatigue. Deux conducteurs ont été étudiés: un ACSR Drake et un ACSR Bersfort. Ces mesures ont permis de connaître la nature des efforts agissant sur ces fils. Lors du chargement statique, des déformations plastiques sont observables à une tension équivalente à 30\% de la résistance maximale en tension. Le mode de déformation le plus important près du DPC est par flexion binormale, quoique les déformations en traction soient aussi importantes. Lors d'un essai de fatigue, le chargement alterné découlant de la vibration du conducteur est principalement ressenti par un fil comme étant une traction alternée.
Suite à cette constatation, un modèle par éléments finis n'impliquant qu'un chargement en traction (outre l'application d'une force de contact reproduisant le serrage du chapeau de la pince de suspension) a été développé. La technique de l'analyse globale locale a été utilisée afin de rendre plus efficace la modélisation 3D du problème. Des simulations en domaine élastique et élastoplastique ont permis de déduire les conditions de contact existant entre un fil de conducteur et le berceau d'une pince de suspension, avec un intérêt particulier pour les microglissements.
Les microglissements jouent un rôle important dans le processus de fatigue par petits débattements. Il est donc important d'obtenir un ordre de grandeur de leur amplitude. Il a été observé que les microglissements maximaux pour le cas d'un contact entre un fil et le berceau d'une pince de suspension seraient inférieurs ou du même ordre de grandeur que ceux obtenus dans le cas du contact entre deux spheres. Ce dernier modèle peut donner une évaluation raisonnable des microglissements permettant de développer un indicateur de fatigue tenant compte de la mécanique du contact.
Les microglissements et les contraintes de contact obtenus numériquement peuvent servir à calculer divers indicateurs de fatigue. Le critère de Ruiz et Chen est utilisé afin d'illustrer le fait.
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PIRES, FERNANDO SALLES DA SILVA. "NUMERICAL STUDY ON THE PREDICTION OF FRETTING FATIGUE CRACK NUCLEATION VIA MULTIAXIAL FATIGUE MODELS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34764@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Esta dissertação revisita quatro modelos multiaxiais de dano por fadiga (SWTD, SWT, Findley e Crossland) e discute a sua aplicação na previsão do risco de nucleação de trinca sob solicitações de fadiga por fretting segundo as abordagens local e não-local. As previsões do risco de nucleação de trinca obtidas através dos modelos estudados foram confrontadas com dados experimentais disponíveis na literatura para o contato cilindro/plano em aços AISI 52100 e AISI 1034 respectivamente. As melhores previsões foram obtidas através da versão desviadora SWTD. Segundo a abordagem local, o modelo SWTD fez previsões menos conservativas que os demais, sendo estas com erros conservativos inferiores a 15 porcento. Segundo a abordagem não-local, os quatro modelos geram previsões com erros inferiores a 15 porcento se os mesmos forem calibrados de forma independente. É importante mencionar que as melhores previsões obtidas através da abordagem não-local (que requer a calibração de um parâmetro adicional) são similares àquelas obtidas por SWTD local. Especificamente para os testes de fadiga por fretting com carga remota, o modelo SWTD não-local gerou previsões com 100 porcento de acertos (13 testes). Segundo a abordagem não-local, foi verificado que, para o conjunto de testes estudado, a precisão nas previsões é mais influenciada pela dimensão característica (que deve ser calibrada) que pelo modelo de fadiga multiaxial ou método de integração considerado. Por fim, verificou-se que previsões não conservativas podem ser obtidas ao se considerar uma dimensão característica assumida como parâmetro material (sem calibração) tal qual a distância crítica proposta por Taylor, definida em termos do método do ponto.
This work presents and discusses four multiaxial fatigue damage models (SWTD, SWT, Findley and Crossland) applied to crack nucleation prediction under fretting fatigue loadings according to the local and the non-local approaches. The predictions have been compared with experimental data available in the literature for the cylinder on flat configuration made of 52100 and 1034 AISI steel s respectively. In particular, for the data set analyzed, SWTD parameter (deviatoric version of SWT model) predictions were less conservative than the ones made by the other three models and have better correlated the experimental results. Considering the local approach, the error observed on the SWTD predictions was lower than 15 percent. On the other hand, for the non-local approach, it has been demonstrated that the four multiaxial fatigue models can provide crack nucleation predictions with similar level of accuracy (error lower than 15 percent) if the characteristic dimension is calibrated model-by-model. Note that this same level of accuracy was obtained with SWTD parameter defined in terms of the local approach, which requires one less parameter to be calibrated (characteristic dimension). In particular, considering only the fretting fatigue tests with bulk stresses, SWTD non-local (area method) prediction accuracy was 100 percent (13 tests). For the material studied, it has also been concluded that the non-local predictions accuracy depends more on the calibrated characteristic dimension than on the multiaxial model or integration method considered. Moreover, it has been verified that non-conservative predictions can be made if the characteristic dimension is assumed as a material property as proposed by Taylor on the critical distances theory (point method).
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SUN, ZHENDE. "Etude du seuil de fissuration a haute frequence en fatigue et en fretting-fatigue." Paris, CNAM, 2000. http://www.theses.fr/2000CNAM0343.
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Ce travail a ete concentre a l'etude du comportement et a la comprehension du mecanisme de fissuration a haute frequence en fatigue et en fretting-fatigue. Les principaux travaux dans cette etude sont : developpement de nouveaux systemes d'essai pour la fissuration et le fretting fatigue a haute frequence ; calcul numeral du facteur d'intensite de contrainte par les elements finis (programme ansys) ; etudes experimentaux du seuil de fissuration a haute frequence en fatigue sur de nombreux materiaux (fonte, aciers inoxydables, tole mince et aciers a ressort) et en fretting-fatigue sur les aciers a hautes resistances ; analyses microstructurelles des mecanismes de fatigue a partir du microscope electronique a balayage. La fatigue vibratoire a haute frequence est un moyen pratique et fiable pour l'etude de comportement de fissuration en fatigue. La frequence n'a pas d'effet significatif sur le seuil de propagation. L'augmentation de temperature due a l'absorption d'energie ultrasonique n'est pas tres importante pour les essais de fissuration a faible vitesse. Comme en fatigue conventionnelle, l'effet du rapport de chargement r et de la fermeture de fissure existe en fatigue vibratoire. Les mecanismes de fissuration sont les memes en fatigue vibratoire qu'en fatigue conventionnelle lorsque la comparaison est possible. Un coefficient de reduction de la limite de fatigue est trouve de 3,5 fois du au fretting. En fretting-fatigue a haute frequence, le mecanisme d'amorcage et propagation des fissures a ete analyse, et le site d'amorcage et la directions de propagation ont ete definis. La duree de vie du fretting-fatigue et determinee par la propagation de la fissure principale. La mecanique de la rupture a ete utilisee pour predire la duree de vie et le seuil de propagation de la fissure principale est correspondant a la limite d'endurance.
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Kubiak, Krzysztof. "Quantification de la fissuration d'un contact soumis à des sollicitations complexes en fretting wear et fretting fatigue." Ecully, Ecole centrale de Lyon, 2006. http://bibli.ec-lyon.fr/exl-doc/TH_T2062_kkubiak.pdf.
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Le but de cette étude est la détermination de la durée de vie en l’amorçage et en propagation d’un acier XC38 (EA1N) utilisé comme matériau pour les essieux-axes de TGV soumis à des sollicitations complexes de fretting fatigue. Cette étude est plus précisément orientée sur la prédiction de l’amorçage des fissures en fonction de charges appliquées et la prédiction de la condition d’arrêt de propagation des fissures. Conformément à cette analyse, l’étude expérimentale se divisera en deux grandes parties : l’une aborde la problématique de la condition d’amorçage alors que l’autre traite des phénomènes de propagation. Dans la première partie, des essais spécifiques de fretting simple et fretting fatigue ont été réalises afin de caractériser les conditions seuil d’amorçage des fissures dans l’acier étudié. Ceci nous conduira à déterminer un seuil d’amorçage en fonction des conditions de chargement. On s’attachera en particulier à la mise en place de méthodes capables de prédire le risque d’amorçage et ainsi pouvoir définir un domaine de sûreté absolue vis à vis de la sollicitation de fretting fatigue. La deuxième partie de ce travail a concerné le problème de la propagation des fissures. Des essais de fretting simple et fretting fatigue ont été réalisés pour déterminer les lois de propagation des fissures avec notamment la mise en évidence des conditions d’arrêt de propagation. La méthodologie développée, qui intègre la propagation des fissures courtes puis des fissures longues, nous a permis de modéliser les courbes de Wöhler en fretting fatigue et surtout de prédire la condition d’arrêt de propagation des fissures en fretting fatigueThe objective of this research focuses on the quantification of the fretting fatigue endurance of XC38 (EA1N) steel alloy used in the TGV axles components. This study mainly concerns the prediction of the crack nucleation and crack arrest conditions under complex fretting and fretting fatigue loadings. Combining experiments and modeling aspect it includes the following two parts. In the first part, fretting wear and fretting fatigue tests have been undertaken and modelized. It was demonstrated a threshold loading condition associated to the crack nucleation process. A specific formulation has been proposed to capture the size effect and provide pertinent and reliable crack nucleation predictions. From this analysis a fretting fatigue crack nucleation boundary has been defined and formalized. The second contribution of this work concerns the formalization of the crack propagation behavior under fretting and fretting fatigue conditions. Specific experiments have been developed to quantify the crack arrest boundaries. By combining crack nucleation, short crack propagation and long crack formulations, the endurance under complex fretting fatigue global situation has been derived. Hence, the fretting fatigue endurance curves have been quantified taking into accounts the respective contribution of fretting and fatigue loadings. Finally a global fretting fatigue chart has been introduced to rationalize the different cracking damages activated under complex fretting fatigue situations
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Moobola, Roy. "Aspects of initiation and self arrest of fretting fatigue cracks." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266559.
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Wavish, Paul M. "Representative specimen for multiaxial fretting fatigue in a splined coupling." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438306.
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Duan, Ruichun Mesmacque Gérard. "Étude de l'endommagement en fretting-fatigue application aux structures boulonnées /." Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/1024.
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Chambon, Laurent 1975. "A unified fracture mechanics approach to fretting fatigue crack growth." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/17506.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2001.Includes bibliographical references (p. 142-154).
The purpose of this work is to demonstrate the adequacy of a modeling approach of fretting fatigue for a sphere-on-flat geometry entirely based on fracture mechanics. All stages of damage evolution, from initiation to failure, are encompassed within the framework of fracture mechanics, in contrast with the general use of stress based criteria to predict crack initiation. A comparison with the classical approaches show how this methodology allows to circumvent the problem of the length scale for initiation by using the crack analogue methodology of contact of Giannakopoulos, Venkatesh, Lindley and Suresh. On the other hand, another length scale, identified as the region of dominance of the singular adhesive stresses, is introduced by the model, and experimental methods to validate it are suggested. The comparison of simulations with three sets of experiments performed on a titanium alloy, with a good control of the normal, tangential and axial loads, shows that the qualitative trends are captured. Good quantitative agreement is also obtained for some of them, depending on the details of the crack growth law. Experimentally, results on the same material after shot peening are reported and used to evaluate the ability of the approach to cope with residual stresses. A good qualitative explanation of the fretting fatigue resistance of the shot peened material is demonstrated. These experiments also serve to illustrate possible testing methods and observations which could yield more useful information than the "classical" fretting fatigue test to failure, and to emphasize the need for a careful stress analysis to avoid plastification under certain material and experimental conditions.
by Laurent Chambon.
S.M.
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Green, Richard. "A study of fretting fatigue incorporating sharp corner contact geometry." Thesis, Sheffield Hallam University, 2003. http://shura.shu.ac.uk/19720/.
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Fretting fatigue occurs when components are in contact and subjected to cyclic loads or vibrations. The following research programme investigates the fretting fatigue phenomenon using a specific flat contact geometry encompassing sharp comers. The pressure distribution at the contact interface is fundamentally important in the understanding of fretting fatigue problems. In the case of sharp comer contacts, the analysis of the pressure distribution results in an infinite gradient occurring at the edges of the contact. The infinite gradients generate deformation singularities and closed form solutions are not available for this contact geometry. The specific contact pressure generates friction forces, which affect the nucleation and growth of dominant fretting cracks by influencing the stress distributions in the region of the contact. The current research programme presents a method of analysing flat contacts containing sharp comers. The method includes the development of a finite element solution capable of accurately predicting the friction force behaviour observed in fretting fatigue. The subsequent numerically determined stress distributions in the contact region are then used to generate a multiaxial stress concentration factor, which provide the basis for a fretting fatigue life prediction method. Furthermore, the research programme investigates the phenomenological effects observed during fretting fatigue. The study investigates friction behaviour and its effects on the initiation of fretting cracks and fretting fatigue lives.
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Duan, Ruichun. "Étude de l'endommagement en fretting-fatigue : application aux structures boulonnées." Lille 1, 2006. http://www.theses.fr/2006LIL10065.
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Ce travail est consacré à l'étude de l'endommagement en fretting fatigue d'un alliage d'aluminium 5086H24 dans un assemblage boulonné. Des essais de fatigue et des essais de fretting - fatigue sont réalisés sur des éprouvettes avec un trou central suivi ou non d'une expansion et sur des assemblages boulonnés en « Alu - Acier ». Une analyse micrographique sur les surfaces de contact et sur les facies de rupture a été réalisée afin d'identifier l'endommagement de contact et les sites d'amorçage. Un calcul aux éléments finis, prenant en compte le contact, a été développé en vue de déterminer les champs de contraintes, de déformations et de déplacements. En l'absence du contact, l'amorçage et la propagation d'une fissure de fatigue sont bien connus, par contre lors du fretting fatigue, nous sommes en présence d'une compétition du fretting et de la fatigue et/ou de la combinaison des deux. Pour notre configuration, avec les investigations expérimentale, micrographique, et de calcul, nous avons identifié les différents sites d'amorçage et leur localisation qui sont directement liés à l'effort normal (pression de contact). Ces sites d'amorçage passent du bord du trou à la frontière de contact avec une orientation qui dépend fortement de l'effort normal. Dans cette étude, nous avons montré que l'expansion du trou n'a pas une influence significative sur la durée de vie et que l'amélioration de celle-ci dépend de la pression de contact. Une Carte de Réponse du Matériau CRM (par analogie au phénomène d'usure et/ou fretting) a été établit pour représenter les conditions de l'amorçage de fissures.
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Pape, John Andrew. "Fretting fatigue damage accumulation and crack nucleation in high strength steels." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/18382.
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Dini, Daniele. "Studies in fretting fatigue with particular application to almost complete contacts." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403712.
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Sum, Wei Siang. "FE-based multiaxial fatigue life prediction of spline couplings undergoing fretting." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420357.
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Barthélemy, François. "Etude de l'amorçage de fissure par fretting fatigue dans des chapes." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37611615h.
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Maslan, Mohamad Haidir. "Development of predictive finite element models for complete contact fretting fatigue." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/development-of-predictive-finite-element-models-for-complete-contact-fretting-fatigue(a4652a74-7429-4f2c-b022-578111608651).html.
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Nucleation and propagation of cracks under fretting conditions has been a subject of study for many years. An extensive experimental investigation to study these cracks was undertaken by Royal Aerospace Establishment (RAE Farnborough). Of particular interest to RAE was an Aluminium alloy (L65) developed for aerospace applications. Many researchers have studied fretting damage and fatigue cracks. Some have examined damage development due to wear, whilst others have analysed cracks under linear elastic fracture mechanics (LEFM) domain. To date, no attempt has been made to develop an integrated numerical model which incorporates all aspects of fretting fatigue i.e. nucleation, initial (or early) crack growth, and long crack propagation. The development of such a model is the principal aim of this work. It is expected that the integrated approach will provide the basis for a standard fretting fatigue analysis of other materials, components, and structures using the finite element method (FEM).This study uses the earlier experimental results with RAE as the reference for comparison. The approach followed is to implement the various stages of fretting in a commercial finite element code, ABAQUS. Unlike previously used simple FE models, both specimen (Aluminium alloy) and the fretting pad (steel) are modelled to simulate the real contact conditions including slip. Various predictive models for crack nucleation (based on damage) and propagation (based on fracture mechanics) are developed, tested, and implemented in ABAQUS. Results clearly show that these models together provide a good estimation tool for predicting total life in complete contact fretting fatigue. It is envisaged that the integrated model will be easily utilised for other materials, components, and structures subjected to fretting fatigue conditions with minimum experimental testing required.
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Hirsch, Michael Robert. "Temperature dependent fretting damage modeling of AISI 301 stainless steel." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52975.
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Prediction of fatigue damage due to fretting is complex due to the number of influential factors and the competitive interaction between wear and fatigue. The majority of current fretting damage modeling approaches are limited to narrow ranges of conditions where little competition between damage mechanisms occurs. Recent models which account for damage interaction are largely phenomenological in nature and are still limited to a narrow range of applicability. A method to characterize and model the level of fatigue damage due to fretting was developed in this work to address the shortcomings of the current methods available by extending the range of conditions captured and enhancing the physical basis of the damage model.
Baseline material properties for thin sheets of AISI 301 stainless steel in the full hard condition were determined as a function of temperature through tensile tests, fatigue tests, and metallography. Fretting experiments were performed for contact between 301 stainless steel and each ANSI A356 aluminum and AISI 52100 steel. Fretting experiments were performed over a range of material combinations, normal forces, displacement amplitudes, atmospheres, and temperatures. Subsequent characterization of the damage due to fretting was performed to determine the level of wear and fatigue damage incurred for each condition tested.
A finite element model of the experiment was created to determine the cyclic stress-strain behavior and local frictional energy dissipation for each condition. Fatigue damage metrics were evaluated to determine the effects of the contact conditions on the driver for fatigue damage. A new model for fatigue damage due to fretting was developed which incorporates the wear behavior to describe the effect of wear on the level of fatigue damage caused by fretting. The level of fatigue damage is influenced using a function of frictional energy dissipation and wear rate to account for differences in wear mechanisms and changes in the severity of wear caused by changes in oxidation behavior and mechanical properties which result from changes in temperature or contacting materials.
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Swalla, Dana Ray. "Microstructural characterization of titanium alloys with fretting damage." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180428/unrestricted/swalla%5fdana%5fr%5f200312%5fphd.pdf.
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Pape, John Andrew. "Design and implementation of an apparatus to investigate the fretting fatigue of PH 13-8 Mo stainless steel." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/18394.
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