Rolling Bearing Stress Based Life—Part I: Calculation Model

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
L. Houpert ◽  
F. Chevalier
Keyword(s):  
Shear Stress ◽  
Endurance Limit ◽  
Rolling Bearing ◽  
Calculation Model ◽  
Rolling Contact ◽  
Surface Stresses ◽  
Bearing Life ◽  
Bearing Load ◽  
Bearing Stress ◽  
Hoop Stresses

Rolling contact bearing life is calculated using stresses calculated at the surface and in the volume. Surface stresses account for profile and misalignment as well as asperity deformations. Sub-surface stresses are calculated beneath the asperities (for defining the life of the surface) and deeper in the volume for calculating the life of the volume. The stress-life criterion adopted is the Dang Van one in which the local stabilized shear stress is compared to the material endurance limit defined as a function of the hydrostatic pressure (itself a function of the contact pressure) but also residual stresses and hoop stresses (due to fit). A stress-life exponent c, of the order of 4 (instead of 34/3 in the standard Lundberg and Palmgren model) is used for respecting a local load-life exponent of 10/3 at typical load levels. Life of any circumferential slices of the inner, outer, and roller is defined for obtaining the final bearing life. Trends showing how the bearing life varies as a function of the applied bearing load and Λ ratio (film thickness/RMS roughness height) are given.

Microstructural Alterations of Rolling—Bearing Steel Undergoing Cyclic Stressing

1966 ◽  
Vol 88 (3) ◽  
pp. 555-565 ◽  
Author(s):  
J. A. Martin ◽  
S. F. Borgese ◽  
A. D. Eberhardt
Keyword(s):  
Shear Stress ◽  
Fatigue Cracking ◽  
Rolling Bearing ◽  
Cyclic Stress ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Microstructural Alterations ◽  
Transmission Electron ◽  
Aisi 52100 ◽  
A Cell

After prolonged cyclic stressing in rolling contact, AISI 52100 bearing steel parts develop extensive regions of microstructural alteration, designated as white etching areas. These are oriented in predictable directions relative to the rolling track. Lenticular carbides are always associated with these areas. Evidence is presented indicating that the boundaries of lenticular carbides constitute planes of weakness which may be preferred planes of fatigue cracking. In the transmission electron microscope the martensitic structure appears gradually transformed into a cell like structure by the action of cyclic stress. The size of crystallites is greatly reduced in this process. The density of microstructural change is found increased with cycling and is distributed in depth along a curve resembling that of the calculated maximum unidirectional shear stress with little or no visible change in the region of maximum orthogonal (alternating) shear stress.

Failure stress modification in fatigue life models for rolling bearings

2019 ◽  
Vol 233 (9) ◽  
pp. 1327-1344 ◽  
Author(s):  
Pradeep K Gupta
Keyword(s):  
Residual Stress ◽  
Shear Stress ◽  
Rolling Contact ◽  
Failure Stress ◽  
Angular Contact Ball Bearing ◽  
Empirical Constant ◽  
Life Data ◽  
Bearing Life ◽  
Model Predictions

The critical subsurface shear stress related to rolling contact fatigue is modified to model the effects of residual stress common in case hardened materials, such as M50-NiL. The role of hoop stress, generated due to race rotation and shrink fits, is also modeled. It is shown that even relatively low levels of compressive residual stress could contribute to notable increase in bearing life. An equivalent life modification factor is dependent on both residual stress and applied load. Model predictions are in agreement with available experimental life data obtained with a 40-mm angular contact ball bearing with M50-NiL races and silicon nitride balls. The stress modification approach is also applied to model the role of any fatigue limiting shear stress, such that the solutions converge to validated Lundberg–Palmgren solutions as limiting stress reduces to zero. However, bearing life predictions at light loads, under any reasonable limiting stress, are unreasonably high. As an alternate approach, the empirical constant in the limiting stress model, with a prescribed limiting stress, is determined by least-squared regression between model predictions and available experimental life data. With such an approach, the least-squared deviation between model predictions and experimental data shows a monotonic increase as a function of the limiting stress with a minimum at no limiting stress. This observation suggests that simple failure stress modification in the current subsurface stress-based models may not be suitable to implement any fatigue limiting stress for rolling contacts.

Load Ratings and Fatigue Life Prediction for Ball and Roller Bearings

1970 ◽  
Vol 92 (1) ◽  
pp. 16-20 ◽  
Author(s):  
J. I. McCool
Keyword(s):  
Environmental Variables ◽  
Life Prediction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Load Rating ◽  
Bearing Load ◽  
Simple Generalization ◽  
Practical Life

A review of current rolling bearing load rating and life prediction practices is given, based on the ASA standard method. Experimental results show the existence of life-factors in addition to those encompassed in the ASA standard. A more general rolling contact fatigue theory is sketched but is not yet at a stage where it can be applied to practical life calculations. Therefore a simple generalization of ASA life formulas is proposed for practical use, which accounts for material and environmental variables by multiplicative factors and permits life prediction for any desired reliability using another, tabulated factor.

Application of a rolling bearing life model with surface and subsurface survival to hybrid bearing cases

2019 ◽  
Vol 233 (15) ◽  
pp. 5491-5498 ◽  
Author(s):  
Guillermo E Morales-Espejel ◽  
Antonio Gabelli
Keyword(s):  
Contact Fatigue ◽  
Load Condition ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Additional Stress ◽  
Subsurface Region ◽  
Light Load ◽  
Bearing Life ◽  
Life Model ◽  
Hybrid Bearing

A previously published rolling bearing life model that separates the surface and subsurface survival is briefly summarised. The model is applied to the case of hybrid bearings and discussed with regard to a selected set of application examples. Ball hybrid bearings under equal load condition show 12% higher Hertzian stress than all-steel bearings. However, field applications, typically under light load, poor lubrication and contamination, show that hybrid bearings have longer fatigue life than all-steel bearings. Traditional all-steel life models fail to predict this type of behaviour. In this paper, it is shown that hybrid bearing unique fatigue performance can be described using the idea of separation of surface and subsurface survival. The model applies the classical rolling contact fatigue in the subsurface region of the rolling contact while a newly developed tribologically dependent surface degradation models is used for the ceramic-steel raceway interface. It is found that the particular fatigue resistance of the ceramic-steel interface of the hybrid bearing raceway can, in most cases, compensate for the additional stress present in the subsurface region of the contact.

Efficiency of application of the phase-chronometric method and neurodiagnostics for monitoring the degradation of rolling bearings during operation

2020 ◽  
pp. 43-50
Author(s):  
A.S. Komshin ◽  
K.G. Potapov ◽  
V.I. Pronyakin ◽  
A.B. Syritskii
Keyword(s):  
Life Cycle ◽  
Wavelet Analysis ◽  
Metrological Support ◽  
Rolling Bearing ◽  
Technical Condition ◽  
Measurement Information ◽  
Rolling Bearings ◽  
Vibration Diagnostics ◽  
Bearing Life ◽  
Alternative Approach

The paper presents an alternative approach to metrological support and assessment of the technical condition of rolling bearings in operation. The analysis of existing approaches, including methods of vibration diagnostics, envelope analysis, wavelet analysis, etc. Considers the possibility of applying a phase-chronometric method for support on the basis of neurodiagnostics bearing life cycle on the basis of the unified format of measurement information. The possibility of diagnosing a rolling bearing when analyzing measurement information from the shaft and separator was evaluated.

scholarly journals Estimation of rolling bearing life with damage curve approach

2011 ◽  
Vol 18 (3) ◽  
pp. 66-70 ◽  
Author(s):  
H. Mehdigholi ◽  
H. Rafsanjani ◽  
Behzad Mehdi
Keyword(s):  
Natural Frequency ◽  
Damage Mechanics ◽  
Calculated Data ◽  
Life Time ◽  
Rolling Bearing ◽  
Vibratory System ◽  
Outer Race ◽  
Bearing Life ◽  
Proposed Model ◽  
Acceleration Amplitude

Estimation of rolling bearing life with damage curve approach The ability to determine the bearing life time is one of the main purposes in maintenance of rotating machineries. Because of reliability, cost and productivity, the bearing life time prognostic is important. In this paper, a stiffness-based prognostic model for bearing systems is discussed. According to presumed model of bearing and fundamental of damage mechanics, damage curve approach is used to relate stiffness of vibratory system and bearing running life. Furthermore, using the relation between acceleration amplitude at natural frequency and stiffness, final relation between acceleration amplitude at natural frequency and running life time according to damage curve approach can be established and the final running time is predicted. Experiments have been performed on self alignment bearing under failures on inner race and outer race to calibrate and to validate the proposed model. The comparison between model-calculated data and experimental results indicates that this model can be used effectively to predict the failure lifetime and the remaining life of a bearing system.

scholarly journals Electrical Discharges in Oil-Lubricated Rolling Contacts and Their Detection Using Electrostatic Sensing Technique

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 392
Author(s):  
Kamran Esmaeili ◽  
Ling Wang ◽  
Terry J. Harvey ◽  
Neil M. White ◽  
Walter Holweger
Keyword(s):  
High Current Density ◽  
Rolling Contact ◽  
Voltage Measurement ◽  
Electrical Discharges ◽  
Steel Rolling ◽  
Bearing Life ◽  
Wide Range ◽  
Robust Techniques ◽  
Rolling Elements ◽  
Current Densities

The reliability of rolling element bearings has been substantially undermined by the presence of parasitic and stray currents. Electrical discharges can occur between the raceway and the rolling elements and it has been previously shown that these discharges at relatively high current density levels can result in fluting and corrugation damages. Recent publications have shown that for a bearing operating at specific mechanical conditions (load, temperature, speed, and slip), electrical discharges at low current densities (<1 mA/mm2) may substantially reduce bearing life due to the formation of white etching cracks (WECs) in bearing components, often in junction with lubricants. To date, limited studies have been conducted to understand the electrical discharges at relatively low current densities (<1 mA/mm2), partially due to the lack of robust techniques for in-situ quantification of discharges. This study, using voltage measurement and electrostatic sensors, investigates discharges in an oil-lubricated steel-steel rolling contact on a TE74 twin-roller machine under a wide range of electrical and mechanical conditions. The results show that the discharges events between the rollers are influenced by temperature, load, and speed due to changes in the lubricant film thickness and contact area, and the sensors are effective in detecting, characterizing and quantifying the discharges. Hence, these sensors can be effectively used to study the influence of discharges on WEC formation.

Research on the Approach for the Assessment of Subsurface Rolling Contact Fatigue Damage

2013 ◽  
Vol 395-396 ◽  
pp. 845-851
Author(s):  
Xiao Feng Qin ◽  
Da Le Sun ◽  
Li Yang Xie
Keyword(s):  
Shear Stress ◽  
Friction Coefficient ◽  
Fatigue Damage ◽  
Stress Ratio ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Critical Stresses ◽  
Orthogonal Shear Stress

In this paper, the distribution of different critical stresses, which were used in previous correlation articles for the assessment of subsurface rolling contact fatigue damage, was analyzed. The rationality of orthogonal shear stress was selected as the key stress controlling the subsurface rolling contact fatigue damage was clarified. Base on the linear fatigue damage accumulative theory and the modification equation for the range of asymmetrical stress, the influence of friction on subsurface rolling contact fatigue damage was studied. The results show that the subsurface orthogonal shear stress is a completely symmetrical stress when the friction coefficient is zero, while it is an asymmetrical stress with considering the friction. The stress ratio of subsurface orthogonal shear stress and subsurface rolling contact fatigue damage is increased with the increasing of friction.

Rolling Element Bearing Non-Linearity Effects

2000 ◽  
Author(s):  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Equations Of Motion ◽  
Rolling Element Bearing ◽  
Radial Clearance ◽  
Rotor Systems ◽  
Bearing Life ◽  
Rolling Element ◽  
Bearing Load ◽  
Rolling Elements ◽  
Element Bearing ◽  
Negative Clearance

Non-linearity effects in rolling element bearings arise from two sources, viz. the Hertzian force deformation relationship and the presence of clearance between the rolling elements and the bearing races. Assuming that centrifugal effects may be neglected and that the presence of axial preload is appropriately reflected in a corresponding change in the radial clearance, this paper analyses a simple test rig to illustrate that non-linear phenomena such as synchronous multistable and nonsynchronous motions are possible in simple rigid and flexible rotor systems subjected to unbalance excitation. The equations of motion of the rotor bearing system were solved by transient analysis using fourth order Runge Kutta. Of particular interest is the effect of clearance, governed in practice by bearing specification and the amount of preload, on the vibration behaviour of rotors supported by ball bearings and on the bearing load. It is shown that in the presence of positive clearance, there exists an unbalance excitation range during which the bearing is momentarily not transmitting force owing to contact loss, resulting in rolling element raceway impact with potentially relatively high bearing forces; and indicating that for long bearing life, operation with positive clearance should be avoided in the presence of such unbalance loading. Once the unbalance excitation is high enough to avoid such contact loss, it is the bearings with zero or negative clearance which produce maximum bearing forces.

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