Compressive Residual Stresses Effect on Fatigue Life of Rolling Bearings

2007 ◽  
Author(s):  
Spiridon S. Cretu ◽  
Marcelin I. Benchea ◽  
Ovidiu S. Cretu
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Equivalent Stress ◽  
Rolling Contact ◽  
Deformation Analysis ◽  
Ball Bearings ◽  
Analysis Model ◽  
Loading Cycle ◽  
Von Mises ◽  
Compressive Residual Stresses

The fatigue life tests carried out on two groups of ball bearings confirm the positive influence of the compressive residual stresses induced by a previous loading in the elastic-plastic domain. The values of residual stresses are numerically evaluated by employing a three-dimensional strain deformation analysis model. The model is developed in the frame of the incremental theory of plasticity by using the von Mises yield criterion and Prandtl-Reuss equations. To consider the material behaviour the Ramberg-Osgood stress-strain equation is involved and a nonlinear equation is considered to model the influence of the retained austenite. To attain the final load of each loading cycle the two bodies are brought into contact incrementally, so that for each new load increment the new pressure distribution is obtained as the solution of a constrained system of equation. Conjugate gradients method in conjunction with discrete convolution fast Fourier transform is used to solve the huge system of equations. Both the new contact geometry and residual stresses distributions, are further considered as initial values for the next loading cycle, the incremental technique being reiterated. The cyclic evaluation process of both plastic strains and residual stresses is performed until the material shakedowns. Comparisons of the computed residual stresses and deformed profiles with corresponding measured values reveal a good agreement and validate the analysis model. The von Mises equivalent stress, able to include both elastic and residual stresses, is considered in Ioannides-Harris rolling contact fatigue model to obtain theoretical lives of the ball bearings groups. The theoretical analysis reveals also greater fatigue lives for the ball bearings groups with induced residual stresses than the fatigue lives of the group without induced residual stresses.

Improvement of Rolling Contact Fatigue Life by a Preliminary Loading in Elastic-Plastic Domain

2008 ◽  
Author(s):  
Spiridon Cretu
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Ball Bearings ◽  
Loading Cycle ◽  
Elastic Plastic ◽  
Plastic Domain ◽  
Von Mises

An analysis model has been developed to model the nonlinear strain rate dependent deformation of rolling bearing steel stressed in the elastic-plastic domain. The model is developed in the frame of the incremental theory of plasticity by using the von Mises yield criterion and Prandtl-Reuss equations. By considering the isotropic and non-linear kinematic hardening laws of Lemaitre-Caboche, the model accounts for the cyclic hardening phenomena. To attain the final load of each loading cycle, the two bodies are brought into contact incrementally. For each new load increment new increments for the components of stress and strain tensors, but also increments of residual stresses, are computed for each point of the 3D mesh. Both, the new contact geometry and residual stresses distributions, are further considered as initial values for the next loading cycle, the incremental technique being reiterated. The cyclic evaluation process of both, plastic strains and residual stresses is performed until the material shakedowns. The experimental part of the paper regards to the rolling contact fatigue tests carried out on two groups of line contact test specimens and on two groups of deep groove ball bearings. In both cases, the experimental data reveal more than two times greater fatigue life for the group with induced residual stresses versus the life of the reference group. The von Mises equivalent stress is considered in Ioannides-Harris rolling contact fatigue model to obtain theoretical lives. The theoretical analysis revealed greater fatigue lives for the test specimens and for the ball bearings groups with induced residual stresses than the fatigue lives of the corresponding reference groups.

Analysis of Residual Stresses Impact on Fatigue Life of Rolling Contacts

2007 ◽  
Author(s):  
S. Cretu ◽  
M. Benchea
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Reference Group ◽  
Yield Criterion ◽  
Rolling Contact Fatigue ◽  
Equivalent Stress ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Deformation Analysis ◽  
Von Mises

The values of residual stresses resulting from a heavily stressed contact are numerically evaluated by employing a three-dimensional strain deformation analysis model. The model is developed in the frame of the incremental theory of plasticity including the von Mises yield criterion, Prandtl-Reuss equations, and Ramberg-Osgood stress-strain equation. Two groups of cylindrical specimens were subjected to rolling contact fatigue, one as the reference group and the other with an induced residual stresses state. To obtain theoretical lives of the tested groups the von Mises equivalent stress is used in Ioannides-Harris rolling contact fatigue model. Both, the experimental data and theoretical analysis reveal more than two times greater fatigue life for the group with induced residual stresses versus the life of the reference group.

Enhancement of roller bearing fatigue life by innovative production processes

2019 ◽  
Vol 71 (8) ◽  
pp. 1003-1006
Author(s):  
Florian Pape ◽  
Oliver Maiss ◽  
Berend Denkena ◽  
Gerhard Poll
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Hard Turning ◽  
Roller Bearing ◽  
Rolling Contact ◽  
Deep Rolling ◽  
Process Step ◽  
Content Type ◽  
Machine Elements ◽  
Compressive Residual Stresses

Purpose The efficient and economical use of natural resources is a big issue. Machine elements with a rolling contact are highly relevant because of their wide application in technical systems and a large production quantity. Innovative hard machining can reduce the friction and increase the fatigue strength of rolling element bearings. The purpose of this study is to focus on the surface properties of such parts. Design/methodology/approach A new model to predict bearing fatigue life is presented which takes compressive residual stresses in the bearing subsurface area into consideration. The investigated bearings were machined by the processes of hard turning, hard turning with subsequent deep rolling and a combination of hard turning and deep rolling (turn-rolling) in one process step. Changes in the residual stress state during bearing fatigue tests were investigated and the influence of residual stresses on the bearings fatigue life was researched. Findings Both combinations including the deep rolling process decrease the surface roughness and induce compressive residual stresses. As a result, the L10 fatigue life of roller bearings was increased by the factor of 2.5. Owing to the developed models, this effect can be considered within the design process. Originality/value In the context of the research program “Resource efficient Machine Elements (SPP1551),” machining processes of bearings were investigated regarding the bearing fatigue life. By inducing beneficial residual stresses on the bearings’ subsurface area, the fatigue life could be increased. Thus higher resource efficiency was achieved. To increase the productivity, a combination of hard turning and deep rolling was evaluated.

On Modeling the Rolling Contact Fatigue Performance Based on Residual Stresses Generated by Superfinish Hard Turning

2000 ◽  
Author(s):  
Salah R. Agha ◽  
C. Richard Liu
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Hard Turning ◽  
Rolling Contact Fatigue ◽  
Equivalent Stress ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Contact Fatigue Life ◽  
The Difference

Abstract It was shown earlier [Agha and Liu, 1998, 1999, 2000] that different cutting conditions, within superfinish hard turning, would lead to significantly different rolling contact fatigue lives. In this study, residual stresses were measured. The rolling contact fatigue life was then modeled using a maximum modified equivalent stress that takes residual stresses into account. It is seen that the maximum modified equivalent stress is a better predictor than the maximum Hertzian stress, but, still not accurate, given the consistent repeatability of the tested workpieces [Agha and Liu, 2000]. The difference in the nature of residual stresses produced by grinding and hard turning is used to show why the inclusion of the maximum modified equivalent stress, its location and the volume at risk, improves the power of the model to predict the rolling contact fatigue lives of the hard turned surfaces. This model is the best up to date for predicting the fatigue life of a surface, especially when residual stress is a factor.

The Effect of Several Finishing Processes on the Fatigue Resistance of Hole Surfaces

1989 ◽  
Vol 111 (1) ◽  
pp. 71-73 ◽  
Author(s):  
M. O. Lai ◽  
A. Y. C. Nee
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Resistance ◽  
Radial Direction ◽  
Fatigue Loading ◽  
Steel Plates ◽  
Finishing Processes ◽  
Compressive Residual Stresses

This investigation examines the effects of different finishing processes on the fatigue life of premachined holes in Assab 760 steel plates. The finishing processes studied were reaming, ballizing, and emery polishing. A general decrease in fatigue life with increase in surface roughness is observed for all the processes employed. In comparing the different processes, for a constant surface roughness, polishing is generally found to give the longest fatigue life while ballizing, in spite of the greater compressive residual stresses induced on the surface of the finished hole, the shortest. The surprising phenomenon was found to be attributed to the amount of plastic deformation occurred before fatigue loading. For Assab 760 steel, a prestrain in the radial direction of less than about 2.5 percent appeared to reduce the fatigue resistance of the material.

Investigation of Residual Stresses in a Sleeve Coldworked Lug Specimen by Neutron and X-ray Diffraction

1994 ◽  
Vol 38 ◽  
pp. 455-461
Author(s):  
R. Lin ◽  
B. Jaensson ◽  
T. M. Holden ◽  
R. B. Rogge ◽  
J. H. Root
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Cracks ◽  
Fatigue Properties ◽  
Aircraft Industry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initiation And Propagation ◽  
Structural Parts ◽  
Compressive Residual Stresses

Sleeve coldworking (SCW) is a mechanical process used in the aircraft industry to strengthen fastener holes of structural parts. By cold-expanding the holes, compressive residual stresses and a high dislocation density are introduced around the holes, the effect of which is to counteract the initiation and propagation of fatigue cracks and thus increase the fatigue life of the parts. The knowledge of residual stress due to SCW is therefore crucial for assessing the fatigue properties of a treated part. In this study, residual stresses were investigated, by employing neutron and X-ray diffraction methods, in a lug specimen that was sleeve coldworked and fatigued. The specimen had been used for testing the influence of the SCW process on fatigue life and crack propagation behaviour under constant amplitude or variable amplitude cyclic loading.

scholarly journals Component Hardness Differences and Their Effect on Bearing Fatigue

1967 ◽  
Vol 89 (1) ◽  
pp. 47-54 ◽  
Author(s):  
E. V. Zaretsky ◽  
R. J. Parker ◽  
W. J. Anderson
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Load Capacity ◽  
Full Scale ◽  
Contact Temperature ◽  
Rolling Element Bearings ◽  
Rolling Element ◽  
Rolling Elements ◽  
Compressive Residual Stresses

The five-ball fatigue tester and full-scale rolling-element bearings were used to determine the effect of component hardness differences of SAE 52100 steel on bearing fatigue and load capacity. Maximum fatigue life and load capacity are achieved when the rolling elements of a bearing are one to two points (Rockwell C) harder than the races. There appears to be an interrelation among compressive residual stresses induced in the races during operation, differences in component hardness, and fatigue life. Differences in contact temperature and plastically deformed profile radii could not account for differences in fatigue life.

Influence of Internal Stresses on the Stressing of Material in Components Subjected to Rolling-Contact Loads

1984 ◽  
Vol 106 (4) ◽  
pp. 499-504 ◽  
Author(s):  
E. Broszeit ◽  
J. Adelmann ◽  
O. Zwirlein
Keyword(s):  
Half Space ◽  
Stress Level ◽  
Maximum Stress ◽  
Equivalent Stress ◽  
Local Stress ◽  
Rolling Contact ◽  
Internal Stresses ◽  
Contact Loads ◽  
Distortion Energy ◽  
Von Mises

The stressing of a material in concentrated contacts can be calculated using f.e. the equivalent stress hypothesis by Huber, von Mises, Hencky (distortion energy hypothesis). The stress level can be directly related to the local yield properties of the material. For the calculation of the equivalent stress the influence of friction and internal stresses in the material have to be taken into account. The local stress level in the half space strongly depends on friction and internal stresses. It will be demonstrated, that it is necessary to have a look at a greater part of the full half space to find the maximum stress level.

Effects of Ultrasonic Deep Rolling on Fatigue Performance of Pre-Corroded 7A52 Aluminum Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 897-900 ◽  
Author(s):  
Xiong Lin Ye ◽  
You Li Zhu ◽  
Dong Hu Zhang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Residual Stresses ◽  
Fatigue Behavior ◽  
Fatigue Performance ◽  
Deep Rolling ◽  
Fatigue Crack Nucleation ◽  
7A52 Aluminum Alloy ◽  
Compressive Residual Stresses

The effects of ultrasonic deep rolling (UDR) on the fatigue behavior of pre-corroded 7A52 aluminum alloys were investigated. By means of X-Ray diffraction stress measurements and scanning electron microscopy (SEM), residual stress and fractograph of 7A52 aluminum alloys with and without UDR treatment were analyzed. The results indicated that the UDR produced compressive residual stresses with depth approaching 1mm. UDR treatment can extend the fatigue life of the pre-corroded 7A52 specimens to a large extent, depending on the level of corrosion and UDR parameter. For the slightly corrode specimens, the UDR treatment changed the fatigue crack nucleation site from surface to the transition zone between the compressive residual stresses and tensile stresses, resulted in a much longer fatigue life. For the severely corrode specimens, the crack still nucleated by intergranular cracking, however, due to the compressive residual stresses introduced and the closure of the corrosion pits and corrosion micro-crocks, UDR treatment still improved fatigue performance of the pre-corroded 7A52 aluminum alloy substantially.

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