scholarly journals Role of multiaxial stress state in the hydrogen-assisted rolling-contact fatigue in bearings for wind turbines

2015 ◽  
Vol 9 (33) ◽  
pp. 434-443
Author(s):  
J. Toribio ◽  
M. Lorenzo ◽  
D. Vergara
Keyword(s):  
Stress State ◽  
Wind Turbines ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Multiaxial Stress ◽  
Multiaxial Stress State

A New Methodology to Evaluate the Rolling Contact Fatigue Performances of Bearing Steels With Surface Dents: Application to 32CrMoV13 (Nitrided) and M50 Steels

2003 ◽  
Author(s):  
D. Ne´lias ◽  
C. Jacq ◽  
G. Lormand ◽  
G. Dudragne ◽  
A. Vincent
Keyword(s):  
Test Specimen ◽  
Normal Load ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Experimental Procedure ◽  
Bearing Steels ◽  
Indentation Process ◽  
Hoop Stresses

A new methodology is proposed to evaluate the rolling contact fatigue (RCF) performances of bearing steels in presence of surface dents. The experimental procedure consists in denting the raceway of the test specimen with a hardness machine using spherical diamond tips of different radius, i.e. 200, 400 and 600 μm, and normal loads ranging from 5 to 50 daN. Analysis of various dent geometries yields to an analytical law with five parameters useful to fit experimental profiles for contact simulation. Besides local residual stresses and plastic strains around the dent have been obtained by finite element simulations of the indentation process. RCF tests performed on a two-disk machine have shown better performances of nitrided 32CrMoV13 steel compared to M50 reference steel. The dominating role of sliding has been highlighted and two areas where damage initiates were identified, while the effects of the normal load and hoop stresses are less marked.

The role of deformed rail microstructure on rolling contact fatigue initiation

Wear ◽  
2008 ◽  
Vol 265 (9-10) ◽  
pp. 1363-1372 ◽  
Author(s):  
John E. Garnham ◽  
Claire L. Davis
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Fatigue Initiation

scholarly journals The Role of Elastohydrodynamic Lubrication in Rolling-Contact Fatigue

1963 ◽  
Vol 85 (3) ◽  
pp. 439-447 ◽  
Author(s):  
E. V. Zaretsky ◽  
L. B. Sibley ◽  
W. J. Anderson
Keyword(s):  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Elastohydrodynamic Lubrication ◽  
Rolling Contact ◽  
Contact Fatigue Life ◽  
Steel Balls ◽  
Thickness Measurements ◽  
Ball Test

The five-ball fatigue tester was used to determine the rolling-contact fatigue life of 1/2-inch-diameter M-1 steel balls with four lubricants at 300 deg F. Film thickness measurements were made with the rolling-contact disk machine under simulated five-ball test conditions. Under certain conditions, elastohydrodynamic lubrication was found to exist at initial maximum Hertz stress levels up to 800,000 psi. There appears to be a correlation among the following variables: Plastically deformed profile radius of the ball specimen at ambient temperature; lubricant type; and rolling-contact fatigue. No correlation was found between contact temperature obtained with different lubricants and fatigue life.

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.

Hydrogen-Assisted Rolling-Contact Fatigue of Wind Turbines Bearings

2014 ◽  
Vol 627 ◽  
pp. 157-160
Author(s):  
Jesús Toribio ◽  
Miguel Lorenzo ◽  
Diego Vergara ◽  
Viktor Kharin
Keyword(s):  
Finite Element Method ◽  
Wind Turbines ◽  
Strain State ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
The Finite Element Method ◽  
Simple Estimation ◽  
Service Conditions ◽  
Potential Damage

This work analyses the effects of hydrogen-assisted rolling-contact fatigue on bearings of wind turbines. To this end, the well-known ball-on-rod test to evaluate the resistance to rolling-contact fatigue was simulated by the finite element method for obtaining the stress-strain state undergone by the bearings considering their in-service conditions. Results of this paper allow a simple estimation of the hydrogen amount in potential damage zones of the specimen.

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