Detrimental Effects of Debris Dents on Rolling Contact Fatigue

1999 ◽  
Vol 122 (1) ◽  
pp. 55-64 ◽  
Author(s):  
D. Ne´lias ◽  
F. Ville
Keyword(s):  
Numerical Simulations ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Damage ◽  
Rolling Bearing ◽  
Initiation Site ◽  
Solid Particles ◽  
Rolling Contact ◽  
Bearing Failures ◽  
Ehl Contact

Debris dents produced by solid particles in suspension in oil or grease when they travel through an EHL contact may be at the origin of rolling bearing failures. A summary of an experimental investigation carried out to identify (i) the particle entry ratio, (ii) the mechanisms of particle fragmentation or deformation, (iii) the resulting indentation features, and (iv) the initiation site of subsequent surface damage is presented first. Afterwards, numerical simulations of a dent moving through an EHL contact are performed. A critical slide-to-roll ratio is found. Results of our numerical simulations are analyzed and discussed in relation to the concept of infinite life for rolling bearing applications. [S0742-4787(00)00901-2]

Rolling bearing seizure and sliding effects on fatigue life

2018 ◽  
Vol 233 (2) ◽  
pp. 339-354 ◽  
Author(s):  
Guillermo E Morales-Espejel ◽  
Antonio Gabelli
Keyword(s):  
Fatigue Life ◽  
Numerical Models ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Damage Mechanism ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Frictional Stress ◽  
Lubricated Contacts ◽  
Contact Fatigue Life

The effects of kinematic sliding on rolling contact fatigue life have been discussed in many occasions, often with some disregard of the fundamental principles of tribology. In this paper, the authors’ intention is to discuss this issue with a perspective as objective as possible and performing a study on factual and known scientific knowledge, applying tribology modelling and methods. The effects of kinematic sliding of Hertzian contacts are studied from three different standpoints: (1) by analysing the combination of sliding speed and contact pressure giving rise to seizure, that is high instantaneous contact temperatures leading to film collapse, (2) by assessing the possible effects of sliding to surface traction and fatigue, (3) by discussing other possible effects of sliding in heavily loaded lubricated contacts as the concurrent damage mechanism caused by wear and rolling contact fatigue. Throughout the paper, different numerical models are presented and discussed alongside with some experimental data. This approach provides a comprehensive assessment of the various phenomena related to the kinematic sliding of rolling bearings. The different mechanisms involved and the interaction of sliding with the elastohydrodynamic lubricant film, frictional stress, wear and fatigue are discussed, and their significance to the performance of the bearing is qualified.

Diagnosis of Rolling Bearing by Measuring Time Interval of AE Generation

1999 ◽  
Vol 121 (3) ◽  
pp. 468-472 ◽  
Author(s):  
Takeo Yoshioka ◽  
Atsushi Korenaga ◽  
Hiroki Mano ◽  
Takashi Yamamoto
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Time Interval ◽  
Measuring Time ◽  
Time Intervals ◽  
Measured Time ◽  
Ae Signal ◽  
Kinetics Of

We have developed a new method for measuring time intervals of Acoustic Emission (AE) generation for diagnosis of a radial rolling bearing. The method makes the AE signal itself a trigger of the oscillation of the clock pulse and measures the time interval of AE generation by integration of the clock pulses. The measurement device consists of the threshold, clock, time interval measurement and memory circuit, and was applied to rolling contact fatigue experiments. It was confirmed by the experiments that the measured time intervals of AE generation on the inner raceway or the ball agreed with the value calculated based on the kinetics of the rolling bearing. Moreover, we could identify the elements in which a fatigue crack was propagating by the method before the spalling appeared. The identified elements agreed with the failed elements.

Location of an acoustic emission source in a radially loaded deep groove ball-bearing

1998 ◽  
Vol 212 (1) ◽  
pp. 33-45 ◽  
Author(s):  
D Nélias ◽  
T Yoshioka
Keyword(s):  
Acoustic Emission ◽  
Ball Bearing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Fatigue Initiation ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Subsurface Defect

This paper describes a deep groove ball-bearing analysis which has been developed to simulate acoustic emission occurring during ball-bearing operation. The computer simulation is useful to clarify experimental research on rolling contact fatigue initiation using the acoustic emission technique. Results show the ability of the method to detect and to locate a subsurface defect, due to rolling contact fatigue, before the rolling bearing failure occurs. The subsurface defect can be accurately located within the inner ring of a deep groove ball-bearing operating under radial load.

A Subscale Experimental Investigation on the Influence of Sanding on Adhesion and Rolling Contact Fatigue of Wheel/Rail Under Water Condition

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Wanliang Huang ◽  
Xi Cao ◽  
Zefeng Wen ◽  
Wenjian Wang ◽  
Qiyue Liu ◽  
...  
Keyword(s):  
Feed Rate ◽  
Bulk Material ◽  
Fatigue Cracks ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Particle Diameter ◽  
Surface Damage ◽  
Rolling Contact ◽  
Adhesion Coefficient ◽  
Water Condition

With a subscale rolling-sliding apparatus, the objective of this study is to explore the adhesion and rolling contact fatigue characteristics of wheel/rail rollers with sanding under water condition. Sanding improves adhesion coefficient but aggravates the surface damage of wheel and rail materials. With the particle diameter and feed rate increasing, the adhesion coefficient is further improved. However, the surface damage (spalling and pits) becomes severer as well as the surface roughness. Note that pitting is a special damage type when sanding is used to improve the adhesion. Big pits and fatigue cracks appear on subsurface under larger particle diameter and feed rate conditions. Severe cracks initiate from big pits and develop into material to a depth, which results in bulk material breaking.

scholarly journals Abrasive Wear, Scuffing and Rolling Contact Fatigue of DLC-Coated 18CrNiMo7-6 Steel Lubricated by a Pure and Contaminated Gear Oil

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7086
Author(s):  
Waldemar Tuszyński ◽  
Remigiusz Michalczewski ◽  
Edyta Osuch-Słomka ◽  
Andrzej Snarski-Adamski ◽  
Marek Kalbarczyk ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Solid Particles ◽  
Rolling Contact ◽  
Lubricating Oil ◽  
Gear Teeth ◽  
Ball Rolling ◽  
Gear Oil ◽  
Gear Oils

Due to extreme working conditions of mining conveyors, which contaminate gear oil with solid particles, their transmissions are exposed to intensive abrasion, scuffing, and even rolling contact fatigue (pitting). These effects shorten gear life. To prevent their occurrence, a wear-resistant coating can be deposited on gear teeth. The resistance to abrasive wear, scuffing, and pitting was investigated and reported in the article. Simple, model specimens were used. Abrasive wear and scuffing were tested using a pin-and-vee-block tribosystem in sliding contact. A cone–three-ball rolling tribosystem was employed to test pitting. The material of the test specimens (pins, vee blocks, cones) was 18CrNiMo7-6 case-hardened steel. Two types of DLC (Diamond-like Coatings) coatings were tested, W-DLC and W-DLC/CrN. The vee blocks and cones were coated. Two industrial gear oils were selected to lubricate the specimens: one with a mineral and one with a synthetic PAO (polyalphaolephine) base, as pure oil or contaminated with solid particles from a coal mine. The results show that, to minimize the tendency to abrasion, scuffing, and pitting of specimens made of 18CrNiMo7-6 steel, the W-DLC/CrN coating should be deposited. This coating also gives very good protection when the lubricating oil is contaminated.

Experimental and Fracture Mechanics Study of the Pit Formation Mechanism Under Repeated Lubricated Rolling-Sliding Contact: Effects of Reversal of Rotation and Change of the Driving Roller

1997 ◽  
Vol 119 (4) ◽  
pp. 788-796 ◽  
Author(s):  
Y. Murakami ◽  
C. Sakae ◽  
K. Ichimaru ◽  
T. Morita
Keyword(s):  
Fatigue Crack ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Damage ◽  
Fatigue Tests ◽  
Rolling Contact ◽  
Sliding Contact ◽  
Hydraulic Pressure ◽  
Pit Formation ◽  
Original Crack

Five rolling contact fatigue tests, Tests {1}–{5} have been conducted. In Tests {1}–{3}, when a fatigue crack was initiated on the surface of a follower, the test was halted. Then, in Test {1} the rotating direction was reversed. In Test {2} the follower and driver were interchanged, and in Test {3} the test was continued unchanged. In Test {3} the original crack grew to a pit. In Tests {1} and {2} the original crack immediately stopped propagating. In Tests {4} and {5}, mating with a harder roller, a softer roller was used as the follower in Test {4} and as the driver in Test {5}. A typical pit occurred in Test {4}. In Test {5}, surface damage substantially different from a typical pit was generated. Based on these experimental results, a 3-D crack analysis including the effect of frictional force on the contact surface and oil hydraulic pressure on crack surfaces, was conducted to elucidate the mechanisms of pit formation and surface damage in contact fatigue.

scholarly journals Rail Integrity Experience on the Washington Metro System

2016 ◽  
Author(s):  
Benjamin Frison ◽  
David Y. Jeong
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Damage ◽  
Rolling Contact ◽  
Recent Experience ◽  
Rail Head ◽  
Passenger Rail ◽  
Maintenance Factors ◽  
Rail System ◽  
Rail Service

The Washington Metropolitan Area Transit Authority (WMATA) provides passenger rail service to the nation’s capital. Although the rail system carries only passenger trains, the rail integrity issues that WMATA must manage are similar to those that freight railroads also face. These issues include occurrences of broken rail from internal rail head defects, detection of such defects, and repair of the rail to restore service. Another example is the development of damage on the running surface of the rail, called rolling contact fatigue (RCF). Such surface damage is known to adversely affect the detection of internal rail head defects beneath RCF conditions. While WMATA’s rail integrity issues may be similar to those that freight railroads also encounter, the management of such issues are different, which are also discussed in this paper. This paper describes the recent experience of broken rails on the WMATA rail system. In addition, results from engineering fracture mechanics analyses are presented to help understand how operational, environmental, design, and maintenance factors influence rail failure.

Experimental and Theoretical Investigation on Rolling Contact Fatigue of 52100 and M50 Steels Under EHL or Micro-EHL Conditions

1998 ◽  
Vol 120 (2) ◽  
pp. 184-190 ◽  
Author(s):  
D. Ne´lias ◽  
M.-L. Dumont ◽  
F. Couhier ◽  
G. Dudragne ◽  
L. Flamand
Keyword(s):  
Rolling Contact Fatigue ◽  
Large Population ◽  
Contact Fatigue ◽  
Surface Damage ◽  
Rolling Contact ◽  
Surface Finishing ◽  
Micro Cracks ◽  
Pure Rolling ◽  
Surface Distress

The purpose of this investigation is to clarify the role of roughness on rolling contact fatigue. Tests have been carried out on a two-disk machine, for two rolling bearing steels (52100 and M50), two surface roughnesses corresponding to EHL and micro-EHL conditions (two different surface finishing), three normal loadings (1.5, 2.5 and 3.5 GPa), and under pure rolling or rolling plus sliding conditions. No surface damage has been observed up to 50 106 cycles for tests with smooth specimens. Tests with rough specimens have produced a typical surface damage, called here surface distress, made of a large population of asperity-scale micro-cracks and micro-spalls. The paper describes the surface distress observed, such as micro-cracks and micro-spalls. Surface damages obtained are different for tests under pure rolling conditions and tests under rolling plus sliding conditions. Therefore, the role of the friction direction is underlined. A link is made between our experimental observations and calculations that have been carried out using a transient EHL model. The influence of an indent in a line contact, simulating a micro-spall, is studied. Surface pressure and associated sub-surface stress field are analyzed versus the sliding direction.

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