Fretting Research Papers - Academia.edu (original) (raw)

Top Papers
Most Cited Papers
Most Downloaded Papers
Newest Papers
People
- by
- •
- Mechanical Engineering, Materials Science, Fretting, Fatigue

The final configuration of a cylindrical Hertzian contact, subject to oscillatory shear and undergoing wear, is studied. It is assumed that wear has proceeded for a long time, so that the final, modified contact is wholly adhered. It is shown that the extent of the final contact corresponds to that of the initial adhered region and the pressure distribution, and state of stress at the new contact edge are all derived, so that the environment in which cracks nucleate is well described.

- by Robert Paynter
- •
- Contact Mechanics, Wear, Fretting

"Des composites à matrice alumine contenant des nanoparticules métalliques (FeCr ou Fe) avec ou sans nanotubes de carbone (NTC) et densifiés par frittage flash (Spark Plasma Sintering, SPS) ont été étudiés dans des conditions de frottement oscillant de faible amplitude (fretting-usure) et de glissement alternatif.
Un dispositif de fretting à débattement non imposé a été utilisé pour permettre aux matériaux en contact de s'adapter librement afin de simuler et d'identifier le phénomène de grippage dans différentes conditions de chargement (constant, progressif, avec ou sans ouverture de contact). Une modélisation paramétrique a permis de définir précisément les coefficients de frottement, les seuils de grippage et les énergies dissipées dans le contact. Les résultats obtenus présentent de grandes similitudes à faibles charges, mais on constate systématiquement une transition de charge brutale conduisant à une forte dégradation des composites avec NTC juste avant un grippage prématuré. Un dispositif d'acquisition d'émission acoustique a été utilisé sur certains essais pour identifier et suivre in situ les différentes phases de dégradation observées au cours du frottement.
Des essais complémentaires en glissement alternatif, avec débattements imposés, ont également été réalisés afin de préciser le comportement en usure des composites étudiés. L'ensemble des résultats de fretting et de glissement ont permis de hiérarchiser les performances tribologiques des différents composites et conduit à l'identifier l'évolution des mécanismes d'usure en relation avec la présence d'un tribofilm à l'interface de contact."

- by Aydemir Güralp Ural
- •
- Fretting, Usure, Grippage, Glissement Alternatif

A procedure for quantifying the fretting fatigue damage arising at the edges of complete contacts subject to oscillatory loading is described. This relies on the Williams wedge analysis and permits: (a) the response of any prototype of complex geometry to be predicted, including the amount of fretting damage likely to be experienced and (b) the fretting fatigue strength measured in a simple laboratory experiment to be used to predict, reliably, the behaviour of any engineering component.

- by Robert Paynter
- •
- Contact Mechanics, Fretting, Fatigue (Fracture)
- by Joze Vizintin
- •
- Mechanical Engineering, Lubrication, Fretting, Tribology

• A method to assess thermal bridging heat loss using the outdoor ITT is developed. • The ITT approach is compared with hot box measurements and numerical predictions. • The wind velocity impact on thermal bridging is quantified. • Adjusting procedure for the Ψ-value measured at different wind velocities is developed. • This procedure allows measured and standard Ψ-value comparison. A B S T R A C T Improving the thermal performance of the existing building stock is essential to significantly reduce the overall energy consumption in the building sector. A key objective is the retrofitting of the existing building envelope. A necessary first step in the building envelope optimization process is the assessment of its actual thermal performance. This assessment should be repeated after retrofitting to clearly define the improvements that were made and the heat loss reduction that was achieved. In this study, an efficient, non-destructive, in-situ measurement method, based on an outdoor infrared thermographic survey, is developed to determine the thermal bridging performance. As wind velocity significantly influences the heat losses through the building envelope, this study includes quantification of the wind velocity impact on the Ψ-value. This was assessed by undertaking ITT of the same thermal bridge at various wind velocities, in a controlled environment, in a hot box device. The results showed that the Ψ-value is highly dependent on wind velocity so that measurement of the Ψ-value taken at different wind conditions cannot be directly compared. An adjustment procedure is proposed that can be used to convert the Ψ-value measured at any wind velocity to a standard value corresponding to a velocity of 4 m/s. From a practical point of view, this adjustment procedure makes the methodology widely applicable.

- by annette harte
- •
- Fretting, Offshore Structures, Fretting Wear, Fretting Fatigue

L’objectif de cette etude est de caracteriser, dans des conditions de frottement oscillant de faible amplitude (sollicitation de fretting), des composites a matrice alumine contenant des nanoparticules metalliques (FeCr ou Fe) avec ou sans nanotubes de carbone (NTC) et densifies par frittage flash (Spark Plasma Sintering, SPS). Les essais tribologiques ont ete menes sur un dispositif de fretting fonctionnant a debattements libres : le phenomene de grippage (ou regime de collage) est ainsi directement mis en evidence par une forte reduction de l’amplitude du deplacement et par la fermeture des cycles de fretting. La capacite d’un materiau a differer ce phenomene est evaluee par sa distance totale de glissement.

- by Jean-Yves PARIS
- •
- Nanomaterials Characterization, Nano Composites, Contact Mechanics, Fretting
- by Melih Eriten
- •
- Engineering, Modeling, Finite element method, Fretting
- by Chung Hyun Goh
- •
- Fretting, Crystal Plasticity, Cyclic Plasticity
- by Mitjan Kalin
- •
- Materials Engineering, Mechanical Engineering, Wear, Fretting
- by annette harte
- •
- Engineering, Economics, Design, Performance

L’objectif de cette étude est de caractériser, dans des conditions de frottement oscillant de faible amplitude (sollicitation de fretting), des composites à matrice alumine contenant des nanoparticules métalliques (FeCr ou Fe) avec ou sans nanotubes de carbone (NTC) et densifiés par frittage flash (Spark Plasma Sintering, SPS). Les essais tribologiques ont été menés sur un dispositif de fretting fonctionnant à débattements libres : le phénomène de grippage (ou régime de collage) est ainsi directement mis en évidence par une forte réduction de l’amplitude du déplacement et par la fermeture des cycles de fretting. La capacité d’un matériau à différer ce phénomène est évaluée par sa distance totale de glissement.

- by Aydemir Güralp Ural
- •
- Nanomaterials Characterization, Nano Composites, Contact Mechanics, Fretting

Simulation of fretting wear on the basis of deformation model of Winkler and the given elementary wear law is presented. Comparison between obtained theoretical results and known experimental data is carried out.

- by Ivan Soldatenkov and +1
- •
- Contact Mechanics, Fretting, Tribology

In this study, stress raisers (notches, fretting fatigue and a combination of notch and fretting) were taken into consideration as to its performance in reducing fatigue life. Reduction factor measurements using fatigue sensitivity, q as an effect of the respective stress raiser on fatigue lives were done. Finite element analyses on the consequence of clamping pressure on a notched geometry revealed a further increase in stress concentration at the notch tip for this specific geometry. However, fatigue tests revealed no significant difference in the fatigue lives between the notched and the combined notch and fretting fatigue. Fatigue notch sensitivity, qn was found to be between 0.42 and 0.65 while a fretting notch-like sensitivity, qf calculated from fretting fatigue results using a method by Wharton et al were 3.52 and 3.28 at torque levels 20 Nm and 50 Nm respectively. It was found that the stress concentration factor, kt for the fretting condition was conservative in its value and did not correlate well with the actual fretting reduction factor, kf. Finally, fractorgraphic analysis revealed significant wear for both fretting fatigue specimens and the combined notch and fretting fatigue. However, cracks were only found to originate from the notch tip for the combined notch and fretting fatigue at all alternating stress levels.

- by Mohamed Afiq Rahmat
- •
- Open Access, Fretting, Fatigue, Notch effect

Surface enhancement technologies such as shot peening (SP), laser shock peening (LSP), and low plasticity burnishing (LPB) can provide substantial fatigue life improvement. However, to be effective, the compressive residual stresses that increase fatigue strength must be retained in service. LPB provides thermally stable compression and can be performed in conventional machine shop environments on CNC machine tools. LPB enables the extension of component service lives fatigue limited by various damage mechanisms including foreign object damage (FOD), corrosion fatigue, pitting, and fretting. The thermal and mechanical stability of the compressive layer are briefly reviewed. The LPB process, tooling, and control system are briefly described. Four representative applications are presented: thermal stability in IN718, improved damage tolerance in Ti-6-4 fan blades, mitigation of fretting fatigue damage in Ti-6-4, and improved corrosion fatigue in 17-4PH stainless steel.

- by Paul Prevey
- •
- Materials Science, Fretting, Corrosion, Damage Mechanics

The performance of electroless (EL) Ni – B coated brass contacts under fretting conditions was evaluated. The contact resistance of EL Ni – B coated brass contact was measured as a function of fretting cycles. The surface profile and wear depth of the fretted zone were measured using laser scanning microscope. The study reveals that EL Ni – B coated contacts exhibit better performance under fretting conditions. However, at conditions which are prone for severe oxidation such as, low frequency (3 Hz) or high temperature (155°C), EL Ni – B coated contacts fail to exhibit a better stability. The quick removal of the oxide film by fretting motion, rapid oxidation of the fresh metallic particles and trapping of the oxidation products in the remaining coating, cause the contact resistance to increase to unacceptable levels at such conditions. The study concludes that EL Ni – B coating is not a suitable choice for connector contacts that could experience fretting under highly oxidizing con...

- by Sankara Narayanan TSN
- •
- Quantum Physics, Fretting, Tribology, Low Frequency
- by Robert John
- •
- Mechanical Engineering, Civil Engineering, Titanium, Stress field

Electricity utilities are obliged to developing renewable energy strategies, and electrification of energy sectors to reduce fossil fuels footprint. To accommodate this trend, utilities try to avoid the expensive solution of building new overhead lines and reinforce existing networks through re-conductoring with bigger size conductors or making use of novel designs such as High- Temperature Low-Sag technologies. The effect of conductor structure and material properties on its vibrations and fatigue responses have not yet been captured thoroughly in literature. In this respect, a Finite Element Model has been established in COMSOL Multiphysics to examine the fatigue performance of the composite structure of OHL conductors. To validate the model, simulation results are compared against the standard Poffenberger- Swart theory. The presented work have shown that the vibration and fatigue of bi-metallic conductors is not a linear problem and the assumption of a homogeneous structure does not apply to all conductor sizes. The internal structure of the conductors must be considered rather than a simplified homogeneous assumption especially for multi-layered conductors. The results also showed that trapezoidal conductors experience less fatigue compared to round designs. The FEM analysis are limited to the efficiency and power of used computing resources.

- by Dr Mohammed A . Al Aqil
- •
- Electrical Engineering, Power System, Fretting, Fatigue
- by Frank Talke and +1
- •
- Materials Engineering, Mechanical Engineering, Wear, Fretting
- by Izhak Etsion
- •
- Materials Engineering, Mechanical Engineering, Contact Mechanics, Wear

Abstract A methodology is developed for the prediction of fretting fatigue phenomenon that results in crack initiation in strands of overhead power line conductors. A numerical approach based on finite element analysis is used to obtain the local stress and strain fields for application of crack initiation criteria in the high cycle fatigue regime. Solutions for the stress field in the stabilised state, where further loading cycles no longer introduce changes to the plastic deformation, are obtained using the stationary incremental method. Cases where convergence does not occur due to significant ratcheting are disregarded as low cycle fatigue. Post-treatment analysis that includes localised averaging is used to implement a fatigue criteria that estimates the crack initiation risk. Validation of this approach is made by comparing with results obtained from experimental measurements made on a simplified clamp wire configuration. Analyses of a simplified three-dimensional configuration with fretting is presented for a range of loading parameters and qualitative trends are established, which will prove invaluable for lifespan assessment of overhead power lines.

- by Fikri Hafid
- •
- Mechanical Engineering, Civil Engineering, Materials Science, Structural Engineering
- by A. Ramalho
- •
- Mechanical Engineering, Fretting, Tribology, Temperature
- by Annette Harte
- •
- Engineering, Economics, Fretting, Offshore Structures

In the present article, we study the development of a wear profile in an axially symmetric contact under conditions of gross slip and assumption of the Reye-Archard wear criterion. Simulations are carried out using the method of dimensionality reduction and a full finite element method (FEM) formulation. The calculation time of the proposed model is several orders lower than that of FEM-based models and allows for much higher spatial resolution.

- by A. Papangelo
- •
- Mechanical Engineering, Wear, Fretting, Computation

Composite materials, mainly fibre type ones, are used to respond to crucial demands in engineering applications. Various limitations mean that it is usually impossible to produce structures without mechanical joints. Fretting is an important failure mode for such joints, especially for dynamic loads. This paper sets out to assess the influence of this failure mode—fretting—in association with the effect of displacement, surface treatment with aluminium (anodisation) and the effect of environment, temperature and relative humidity. A series of experiments was carried out, changing each of the variables. To analyse the influence of each parameter, tangential force and displacement were used to establish the fretting cycles for every condition tested. Variations in the shape of the cycles revealed three regimes typical of fretting: stick, slip and partial slip, but the most effective way to characterize the transition between regimes was based on energy dissipation by friction. Surface treatment by anodisation leads to lower wear values, for small amplitude displacements, while for higher displacement amplitudes the wear volume was larger, for the case of room temperature and humidity. Increased temperature resulted in a rise in wear volumes, especially for non-anodised aluminium. Variation in humidity did not greatly influence the behaviour of the specimens studied.

- by Pedro V . Antunes
- •
- Fretting, Temperature, Polypropylene, Relative Humidity

The industrial demand for higher reliability of various components is one of the main flywheels of the research and development in the field of modelling of complex phenomena. There is a need to characterize the wear behaviour of the interface under fretting wear conditions in ball bearing application. Pre-treated experimental data was used to determine the wear of contacting surfaces

- by carlo poloni
- •
- Computer Science, Materials Science, Genetic Programming, Wear
- by Choon Fong Lee
- •
- Engineering, Mechanical Engineering, Materials Science, Finite element method

Modular hip prostheses are flexible to match anatomical variations and to optimize mechanical and tribological properties of each part by using different materials. However, micromotions associated with the modular components can lead to fretting corrosion and, consequently, to release of debris which can cause adverse local tissue reactions in human body. In the present study, the surface damage and residues released during in vitro fretting corrosion tests were characterized by stereomicroscope, SEM and EDS. Two models of modular hip prosthesis were studied: Model SS/Ti Cementless whose stem was made of ASTM F136 Ti-6Al-4V alloy and whose metallic head was made of ASTM F138 austenitic stainless steel, and Model SS/SS Cemented with both components made of ASTM F138 stainless steel. The fretting corrosion tests were evaluated according to the criteria of ASTM F1875 standard. Micromotions during the test caused mechanical wear and material loss in the head-taper interface, resulting ...

ABSTRACT The deep groove ball bearings of an electric motor, driving an oil-injected compressor, were periodically monitored for vibrations. The ball bearings were replaced when before the expected lifetime of the bearing the measured vibration exceeded the tolerated level. The bearing on the axle side of the motor was the locating bearing while the ball bearing of the fan side (where the fan of the electric motor was placed) was mounted as a (spring-loaded) floating bearing.The outer rings of the fan side bearing showed signs of fretting wear. The outer ring of both bearings was ground through to disassemble the bearings. Visual inspection, optical microscopy and scanning electron microscopy of the raceways indicated that the bearings were subjected to an axial load in the range of the permissible axial load, but for each bearing in a different direction. The placement of the wear marks on the raceways of both bearings indicated an axial loading from the inside towards the outside of the electric motor.Also the wear marks on the raceways of both ball bearings showed the typical washboard pattern of the passage of electric current >0.5 A, although the rotor was already equipped with a grounding brush on the non-drive side.While replacing the deep groove ball bearing by a cylindrical roller bearing can easily prevent the fretting wear on the fan side bearing, the origin of the bearing currents merits further investigation.

- by Patrick Baets
- •
- Engineering, Materials Engineering, Mechanical Engineering, Civil Engineering
- by Paul Prevey
- •
- Materials Science, Fretting, Structural Integrity, Corrosion
- by Mitjan Kalin
- •
- Mechanical Engineering, Lubrication, Fretting, Tribology
- by Joze Vizintin
- •
- Mechanical Engineering, Fretting, Tribology, Mathematical Model
- by julien leroux
- •
- Engineering, Contact Mechanics, Fretting, Composite Material
- by Amílcar Ramalho
- •
- Mechanical Engineering, Fretting, Tribology, Temperature
- by Hyo-Chol Sin and +2
- •
- Electron Microscopy, Wear, Fretting, Splines
- by Frank Talke
- •
- Materials Engineering, Mechanical Engineering, Contact Mechanics, Wear
- by michele ciavarella
- •
- Fretting, Fatigue
- by Luminita Irimescu
- •
- Materials Science, Fretting, Fretting Wear
- by Patrick Baets
- •
- Mechanical Engineering, Materials Science, Wear, Fretting
- by Tasic Milan
- •
- Physics, Fretting, Resonance, Oscillations
- by Sankara Narayanan TSN
- •
- Mechanical Engineering, Materials Science, Lubrication, Fretting

This study investigated the mechanical properties of aluminum matrix functionally graded material (FGM) reinforced by integration of aluminum 2014 alloy (AlCu4SiMg) and 15 vol% SiC. The specimens were obtained by centrifugal casting technique, followed by aging treatment. The variations that occurred in microstructure, hardness, Young’s modulus, tensile strength, yield strength, elongation, fatigue, and fretting fatigue behaviors were analyzed. In both cast and aged conditions, it was observed that hardness values and mechanical properties changed between SiC-rich and aluminum-rich regions. Fatigue and fretting fatigue data were similar. It was determined that greater wear was occurring on the pad surfaces compared to that occurring on the sample surfaces.

- by Muzaffer Topcu
- •
- Mechanical Engineering, Materials Science, Fretting, Fatigue

- by muzaffer topcu
- •
- Mechanical Engineering, Materials Science, Fretting, Fatigue

Modularity in total hip replacement offers advantages with regard to biomechanical adjustments and leg lengths. Recently, modular femoral necks were introduced as an added advantage to head modularity permitting further adjustments in femoral version as well as offset and ease of revision. Currently, most necks are made of Ti6Al4V for which cases of in vivo fractures and inseparable neck-stem junctions have been reported. Therefore, we investigated CoCrMo head-Ti6Al4V stem hip replacements with necks made of CoCrMo as an alternative to Ti6Al4V. We compared the two materials with respect to (1) compressive load bearing capacity; (2) fatigue durability; and (3) component distraction. We performed in vitro fatigue-pull-off, microscopy, fatigue durability and compression investigations. The CoCrMo neck showed a load bearing capacity of 18 kN, 38% higher than 13 kN for the Ti6Al4V neck. A fatigue load of 11.2 kN for 1 million cycle failure was achieved with CoCrMo translating into nearly 1000 times longer fatigue life compared to Ti6Al4V necks. The neck-stem distraction force showed large statistical variation and was similar for both neck materials. Overall, the results suggest a superiority of CoCrMo over Ti6Al4V as neck material with regard to mechanical behavior. However, the corrosion behavior was not appropriately assessed and necessitates additional investigations.

- by M. Nganbe
- •
- Orthopedic Surgery, Biomedical Engineering, Treatment, Titanium
- by Jacek Pietraszek
- •
- Stress, Contact Mechanics, Fretting