Rolling–sliding contact fatigue of surfaces with sinusoidal roughness

Abstract

Surfaces of mechanical components under combined rolling and sliding motions may be subjected to accelerated contact fatigue failure due to increased number of microscopic stress cycles and pressure peak heights caused by rough-surface asperity contacts. Available rolling contact fatigue (RCF) theories were developed mainly for rolling element bearings, for which the effect of sliding is usually insignificant. In various types of gears, however, considerable sliding exist in the critical tooth contact area below the pitch line, where excessive wear and severe pitting failures originate. Ignorance of sliding is most likely the reason why the conventional RCF models often overestimate gear fatigue life. This paper studies the effect of sliding motion on the contact fatigue life of surfaces with sinusoidal roughness that mimicks the topography from certain manufacturing processes. A set of simple equations for stress cycle counting is derived. Mixed elastohydrodynamic lubrication simulations are executed with the considerations of normal loading and frictional shear. Relative fatigue life evaluations based on a subsurface stress analysis is conducted, taking into account the two sliding-induced mechanisms, which are the greatly increased number of stress cycles and the pressure peak heights due to surface interactions. Obtained results indicate that sliding leads to a significant reduction of contact fatigue life, and rough surface asperity contacts result in accelerated pitting failure that needs to be considered in life predictions for various mechanical components.

Effect of pressure changes in sliding contact

“…The higher temperature could lead to wear acceleration, resulting in damage of the delivery end of the brush. So, this phenomenon elucidates the accelerated brush surface damage in electrical machines [18,36,46,74]. Now we can evaluate a relative error of the pressure change in the contact area being the function of time: It is interesting to note that the largest error occurs in the area formed under the leading edge of the brush and the commutator that is where a highest sliding velocity at the contact area, whereas the smallest error occurs in the area formed under the trailing edge of the brush where the sliding velocity decreases.…”

“…In the present analysis, we investigate the characteristics of the sliding layer formed by wear particles and gas, using mathematical modeling to improve our understanding of the change in the pressure in the contact area between commutator and brush. The motion of wear particle and air flow in the sliding contact [36][37][38][39][40][41][42][43][44] is the process of major importance in modern technologies, however it has not been studied well enough. Such fact could be explained by the difficulty of observation, as demonstrated in contact mechanics measures when the probe slides across the wear track, or in commutator and brush assembly [42][43][44][45][46] when the brush slides on a slip ring (collector) of electrical machines.…”

Microstress cycle and contact fatigue of spiral bevel gears by rolling-sliding of asperity contact

“…With the presence of the relative sliding between two mating surfaces, the stress cycles may be considerably high because one of the surfaces is inevitably experiencing the many asperities of another surface over the contact zone. Most recently, the significant influence of sliding on fatigue life has been revealed by Ramalho et al [3], Lee et al [4], Seo et al [5], and Oksanen et al [6] experimentally, and Pu et al [7] theoretically. Therefore, conventional RCF theories tend to overestimate the fatigue life of spiral bevel gears as the sliding between the conjugated gear flanks is not considered [8].…”

“…Scholars have made great efforts to develop the mixed elasto-hydrodynamic lubrication (EHL) model with the consideration of roughness. Representative achievements were made by Xu and Sadeghi [18], Zhu and Ai [19], Jiang et al [20], Sicuteri and Salant [21], Hu and Zhu [22], Holmes et al [23], Bayada et al [24], Zhu et al [25,26], et al The developed mixed EHL model has been implemented in the subsurface stress-based fatigue-life model proposed by Zaretsky [12] as an effective approach for pitting fatigue analysis, as reported by Ai [15], Epstein et al [16], Zhu et al [17], Greco et al [27], and Pu et al [7]. Similar combinations of fatigue model and mixed EHL were also applied by Li and Kahraman [28], Li and Anisetti [29], et al Modifications to the mixed EHL model have been attempted in Refs.…”

A Reliable Prognosis Approach for Degradation Evaluation of Rolling Bearing Using MCLSTM

“…El-Tawil et al [10] developed a prognostic methodology based on nonlinear damage to predict the RUL of the system. Pu et al [11] studied the effect of sliding motion on the contact fatigue life of bearings. Wang et al [12] investigated a hybrid prognosis approach for machine condition prognosis of bearings in a wind turbine.…”