Application of a contact fatigue life model to assess the relative risk of surface versus subsurface initiated fatigue in gears
File(s)
Published version
Author(s)
Morales-Espejel, GE
Wainwright, B
Kadiric, A
Type
Journal Article
Abstract
This paper presents a method to assess the relative risk of surface-initiated contact fatigue versus subsurface-initiated fatigue failures under conditions pertinent to gear teeth contacts. The relative risk of surface fatigue is expressed through a parameter SR which is defined as a ratio of near-surface stress integral to total stress integral and calculated using an existing gear fatigue life model. The surface risk parameter is plotted on a failure chart as a function of specific film thickness, Λ and a newly derived surface fatigue criterion, χ which includes effects of surface roughness, Hertz pressure and sliding magnitude on surface fatigue. Parameter χ is expressed as a reciprocal of the well-known plasticity index scaled with applied pressure and slide/rolling ratio. Experimental data is used to validate the predicted chart and identify regions of operating conditions where either micropitting or surface-initiated macropitting or subsurface-initiated spalling are the most likely failure mode. The experimental results are seen to fit well with the trends predicted by the model. The use of new parameter χ together with specific film thickness Λ provides the means for a more comprehensive assessment of the relative risk of micropitting, macropitting and subsurface-initiated spalling in gear teeth contacts than is achievable with simpler parameters. Provided failure charts give an approximate but a simple way to help in assessing the relative risk of surface versus subsurface fatigue failure for a given set of operating conditions.
Date Issued
2025-09-15
Date Acceptance
2025-06-18
Citation
Wear, 2025, 578–579
ISSN
0043-1648
Publisher
Elsevier
Journal / Book Title
Wear
Volume
578–579
Copyright Statement
© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Subjects
DAMAGE
Engineering
Engineering, Mechanical
Gear fatigue
Macropitting
Materials Science
Materials Science, Multidisciplinary
Micropitting
Rolling contact fatigue
Science & Technology
Spalling
Surface life
Technology
Publication Status
Published
Article Number
206216
Date Publish Online
2025-06-20