A note on the crack analogue fretting fatigue model with varying normal load

Fretting-wear and fretting-fatigue loadings can both result in wear (material loss) and in crack nucleation and propagation (fatigue process). This paper deals with cracking induced by small amplitude displacements in the case of aeronautic aluminium alloys. The two sets of fretting maps are introduced: running condition fretting map is composed of partial slip (sticking), mixed fretting and gross sliding regime; material response fretting map is associated with two macro-degradation modes. Crack nucleation and propagation are analysed for every fretting regime. The mixed fretting regime appeared most detrimental with regards to fatigue cracking. Slip amplitude and normal load main effects discussed for fretting wear can be used to justify the fatigue limit decrease often obtained for fretting fatigue experiments.

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Fretting Fatigue Design of Subsea Connectors: A Generalised Approach to Testing

Volume 2A: Structures, Safety, and Reliability ◽

10.1115/omae2020-18608 ◽

2020 ◽

Author(s):

H. Andresen ◽

D. A. Hills ◽

Anders Wormsen ◽

K. A. Macdonald

Keyword(s):

Crack Nucleation ◽

Normal Load ◽

Asymptotic Methods ◽

Fretting Fatigue ◽

Test Design ◽

Frictional Contacts ◽

Fatigue Design ◽

Geometrical Features ◽

Fatigue Data ◽

Constant Normal Load

Abstract In this paper fretting fatigue is addressed as a potential design consideration for wellhead connectors. The study of near-edge relative motion for frictional contacts under constant normal load is described using analytical, numerical and asymptotic methods. Based on published fretting fatigue experimental data an argument is drawn for a generalised fretting fatigue test design. We do this by reducing the parameters responsible for crack nucleation to the smallest number possible and thereby revealing the fretting fatigue strength as a material property independent of geometrical features. Easy to apply recipes are described and thoughts on a potential apparatus are shared with the reader. Commercial potential lies in the wide-ranging applicability of experimental results across many prototypes and loadings once an appropriate amount of fretting fatigue data has been generated for the material in question.

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Analyses of Contact Pressure and Stress Amplitude Effects on Fretting Fatigue Life

Journal of Engineering Materials and Technology ◽

10.1115/1.1288211 ◽

2000 ◽

Vol 123 (1) ◽

pp. 85-93 ◽

Cited By ~ 44

Author(s):

K. Iyer ◽

S. Mall

Keyword(s):

Finite Element ◽

Fatigue Life ◽

Contact Pressure ◽

Stress Amplitude ◽

Normal Load ◽

Contact Region ◽

Local Stress ◽

Fretting Fatigue ◽

Element Analysis ◽

Stress Ratios

Elastic-plastic finite element analyses of a cylinder-on-plate configuration, studied experimentally, were performed to provide an explanation for the decrease in fretting fatigue life with increasing contact pressure. Three values of normal load, namely 1338 N, 2230 N, and 3567 N, and three stress ratios (0.1, 0.5, and 0.7) were considered. Based on a previously determined dependency between contact pressure and friction coefficient, the effect of coefficient of friction was also evaluated. The deformation remained elastic under all conditions examined. Cyclic, interfacial stresses, and slips were analyzed in detail. The amplification of remotely applied cyclic stress in the contact region is shown to provide a rationale for the effect of contact pressure and stress amplitude on life. Comparisons with previous experiments indicate that the local stress range computed from finite element analysis may be sufficient for predicting fretting fatigue life. Further, the results suggest that the slip amplitude and shear traction may be neglected for this purpose.

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Normal load effects in fretting fatigue of titanium and aluminum alloys

Wear ◽

10.1016/0043-1648(74)90029-5 ◽

1974 ◽

Vol 27 (2) ◽

pp. 153-159 ◽

Cited By ~ 13

Author(s):

G.L. Goss ◽

D.W. Hoeppner

Keyword(s):

Aluminum Alloys ◽

Normal Load ◽

Fretting Fatigue ◽

Load Effects

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Fretting-Fatigue Analysis of Shot-Peened Al 7075-T651 Test Specimens

Metals ◽

10.3390/met9050586 ◽

2019 ◽

Vol 9 (5) ◽

pp. 586 ◽

Cited By ~ 2

Author(s):

Vicente Martín ◽

Jesús Vázquez ◽

Carlos Navarro ◽

Jaime Domínguez

Keyword(s):

Fatigue Life ◽

Residual Stresses ◽

Shot Peening ◽

Normal Load ◽

Fretting Fatigue ◽

Fatigue Tests ◽

Material Surface ◽

Tangential Load ◽

Bulk Stress ◽

Al 7075

Shot peening is a mechanical treatment that induces several changes in the material: surface roughness, increased hardness close to the surface, and, the most important, compressive residual stresses. This paper analyzes the effect of this treatment on alloy Al 7075-T651 in the case of fretting fatigue with cylindrical contact through the results of 114 fretting fatigue tests. There are three independent loads applied in this type of test: a constant normal load N, pressing the contact pad against the specimen; a cyclic bulk stress σ in the specimen; and a cyclic tangential load Q through the contact. Four specimens at each of 23 different combinations of these three parameters were tested—two specimens without any treatment and two treated with shot peening. The fatigue lives, contact surface, fracture surface, and residual stresses and hardness were studied. Improvement in fatigue life ranged from 3 to 22, depending on fatigue life. The relaxation of residual-stress distribution related to the number of applied cycles was also measured. Finally, another group of specimens treated with shot peening was polished and tested, obtaining similar lives as in the tests with specimens that were shot-peened but not polished.

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An Investigation into the Effect of Normal Load Frequency on Fretting Fatigue Behavior of Al7075-T6

Tribology Transactions ◽

10.1080/10402004.2017.1371366 ◽

2017 ◽

Vol 61 (3) ◽

pp. 547-559 ◽

Cited By ~ 6

Author(s):

G. H. Majzoobi ◽

F. Abbasi

Keyword(s):

Normal Load ◽

Fatigue Behavior ◽

Fretting Fatigue ◽

Load Frequency

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Some aspects of fretting fatigue under cyclic normal loading

Journal of Mechanical Engineering Research ◽

10.30564/jmer.v1i1.186 ◽

2019 ◽

Vol 1 (1) ◽

Author(s):

Farshad Abbasi ◽

G. H. Majzoobi

Keyword(s):

Fatigue Life ◽

Fatigue Testing ◽

Normal Load ◽

Testing Machine ◽

Low Frequency ◽

Load Condition ◽

Fretting Fatigue ◽

Normal Loading ◽

Drastic Effect ◽

Fretting Damage

Fretting fatigue has been studied mainly under constant normal loading, as it requires simple equipment which can be assembled on a universal fatigue testing machine. Recently, we [1] have introduced an innovative fretting fatigue apparatus in which the contact pressure can independently be varied during the test. In a recent publication [2] we have investigated the effect of normal load frequency on fretting fatigue life of Al7075-T6 under cyclic normal load condition. It was found that the low frequency of normal load has drastic effect on fretting fatigue life. The effect, however, gradually diminishes with the frequency increase and vanishes at the frequency of around 80Hz. In another publication [3] we have compared the results of constant normal loading with those of in phase, 90° and 180° degrees out-of-phase loadings. It was found that the constant normal loading has the least fretting damage, while the maximum fretting damage occurs by in-phase loading. The results also showed that the out-of-phase loading had improving effect on fretting fatigue life with respect to the in-phase condition. Recently, Ciaverella [4] has published a discussion on our publications [2, 3]. He believes that some of our experimental results needs further discussion. Therefore, the objective of this article is to answer three main points he has raised in his article [4]. We hope that this discussion could lead to some progress.

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Prediction of Fretting Fatigue Life of Aluminum Alloy LY12CZ

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.252 ◽

2010 ◽

Vol 146-147 ◽

pp. 252-256

Author(s):

Moo Sheng Yang ◽

Yue Liang Chen ◽

Yu Quan Bi ◽

Wen Hao Jiang

Keyword(s):

Aluminum Alloy ◽

Fatigue Life ◽

Influence Factor ◽

Stress Amplitude ◽

Normal Load ◽

Fretting Fatigue ◽

Damage Parameter ◽

Finite Element Software ◽

Increase With Increase ◽

Bulk Stress

Stress in the interface of contacts was calculated applying finite element software/ABAQUS, with which the Ruiz fretting damage parameter was obtained and the location for crack formation was found. A new model for predicting fretting fatigue life has been presented based on friction work. The rationality and effectiveness of the model were validated according to the contrast of experiment life and predicting life. At last influence factor on fretting fatigue life of aerial aluminum alloy LY12CZ was investigated with the model. The results revealed that fretting fatigue life decreased monotonously with the increasing of normal load and then became constant at higher pressures. At low normal load, fretting fatigue life was found to increase with increase in the pad radius. At high normal load, however, the fretting fatigue life remained almost unchanged with changes in the fretting pad radius. The bulk stress amplitude had the dominant effect on fretting fatigue life. The fretting fatigue life diminished as the bulk stress amplitude increased.

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Evolution of Relevant Parameters on Fretting Fatigue Tests

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.385-387.565 ◽

2008 ◽

Vol 385-387 ◽

pp. 565-568

Author(s):

M. Buciumeanu ◽

A.S. Miranda ◽

F.S. Silva

Keyword(s):

Fatigue Life ◽

Normal Load ◽

High Strength ◽

Degradation Process ◽

Fatigue Behaviour ◽

Fretting Fatigue ◽

Relative Displacement ◽

Fatigue Tests ◽

Tangential Load ◽

Chemical Attack

The degradation process in fretting fatigue is due to mechanical and chemical attack between two contacting surfaces, being directly related to wear, corrosion and fatigue. There are many parameters that influence the fretting fatigue phenomenon out of which relative displacement, δ , normal load, n F , and tangential load t F , are the most important and consequently the most studied ones. This paper describes the fretting fatigue phenomenon occurring on a high strength aluminium alloy, Al7175. The aim of this study is to achieve a better understanding of the fretting fatigue behaviour by observing the evolution of the fatigue life of the specimen with the normal load, the tangential load and the relative displacement amplitude.

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