Finite Element Analysis of the Rolling-Sliding Contact of Vibrationally Loaded Bearings Based on a Micro Friction Model

Abstract:

Mixed friction acting in a rolling contact increases the v. Mises equivalent stress and shifts the maximum towards the surface. Tangential stresses are superimposed to the stress distribution. The resulting position of the maximum v. Mises stress depends on the magnitude of the friction coefficient and is located directly on the surface from values of about 0.25 upwards. The impact of three-dimensional machine vibrations on rolling bearings in operation can cause severe mixed friction running conditions. Residual stress distributions measured on indentation-free raceways indicate high friction coefficients of up to greater than 0.25. The surfaces reveal smoothing of the finishing structure but no adhesive wear. The simulation of the vibrationally loaded rolling-sliding contact is based on the tribological model of localized friction coefficient. This approach avoids seizing by allowing for increased friction only in intermittently changing subareas of the contact at low sliding speed. The macroscopic friction coefficient, meeting a mixing rule, does not exceed 0.1. The finite element method (FEM) is used for the stress analysis. In the first step, a simplified FEM model involves a circumferentially oriented band of high friction coefficient from 0.2 to 0.5 within a cylindrical roller contact. The resulting depth distributions of the v. Mises equivalent stress during overrolling and the corresponding residual stresses are evaluated below the inner ring raceway of the bearing. The features of the FEM model are discussed in detail. The increased sliding friction in the band shifts the maximum of the v. Mises equivalent stress to the surface. Compressive residual stresses are induced in the edge zone. Depending on the applied Hertzian pressure, an additional subsurface peak occurs. First results of the finite element analysis are presented.

• Periodical: Materials Science Forum (Volumes 768-769)
• Pages: 714-722
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.768-769.714
• Online since: September 2013
• Authors: Andreas Konrad, Wolfgang Nierlich, Jürgen Gegner
• Keywords: Finite Element Method (FEM), Machine Vibrations, Mixed Friction, Residual Stress, Rolling Contact, Tribological Model

References

[1] J. Gegner, Tribological Aspects of Rolling Bearing Failures, in: C. -H. Kuo (Ed. ), Tribology – Lubricants and Lubrication, Chap. 2, InTech, Rijeka, Croatia, 2011, pp.33-94.

DOI: 10.5772/20790

[2] J. Gegner, W. Nierlich, Operational Residual Stress Formation in Vibration-Loaded Rolling Contact, Adv. X-ray Anal. 52 (2008) 722-731.

DOI: 10.1154/1.2951858

[3] W. Nierlich, J. Gegner, Material Response Bearing Testing under Vibration Loading, in: J.M. Beswick (Ed. ), Advances in Rolling Contact Fatigue Strength Testing and Related Substitute Technologies, STP 1548, ASTM International, West Conshohocken, Pennsylvania, USA, 2012, paper ID: STP104653T.

DOI: 10.1520/stp104653t

[4] J. Gegner, W. Nierlich, Service Loading of Wind Turbine Gearbox Rolling Bearings based on X-ray Diffraction Residual Stress Measurements, Mater. Sci. Forum, accepted for publication.

DOI: 10.4028/www.scientific.net/msf.768-769.723

[5] E. Broszeit, J.F. Heß, K.H. Kloos, Werkstoffanstrengung bei oszillierender Gleitbewegung, Z. Werkstofftech. 8 (1977) 425-432.

DOI: 10.1002/mawe.19770081208

[6] W. Nierlich, J. Gegner, Material Response Models for Sub-Surface and Surface Rolling Contact Fatigue, in: Proc. 4th Int. Conf. on Mathematical Modeling and Computer Simulation of Materials Technologies MMT-2006, College of Judea and Samaria, Ariel, Israel, 2006, Vol. 1, Chap. 1, pp.182-192.

[7] Y.B. Guo, C.R. Liu, Mechanical Properties of Hardened AISI 52100 Steel in Hard Machining Processes, ASME J. Manuf. Sci. Eng. 124 (2002) 1-9.

DOI: 10.1115/1.1413775