Microstructure Stress State Evaluation of Contact Fatigue in Gears

Farnoosh Farhad, Adrian Oila

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Surfaces subjected to rolling and sliding may suffer from contact fatigue such as micropitting which is a common failure mechanism in gears. In order to protect materials from surface contact fatigue and enhance their lifetime, fracture mechanics investigations have a vital role. However, when fracture mechanics is used the microstructural details are usually simplified in order to carry out computer simulations. In this study the influence of microstructure of fatigued gears on the stress distribution is investigated using the image-based Object Oriented Finite Element code (OOF2). OOF2 has the ability to simulate the realistic microstructure by using micrographs obtained by scanning electron microscopy (SEM) or maps from electron backscatter diffraction (EBSD). Fatigue tests were carried out on gears and samples taken in the cross section of the gear tooth as well samples from untested gears were prepared for microscopy and SEM images and EBSD maps were acquired. The acquired maps are used in numerical simulations to study the effect of microstructure on stress distribution. The results show that the decay of martensite strongly affects the stress state in micropitted gears.
Original languageEnglish
Title of host publicationEngineering structural integrity assessment 2015
Subtitle of host publication(ESIA13)
EditorsP. E. J. Flewitt, J. K. Sharples, B. Tomkins
PublisherForum for Engineering Structural Integrity (FESI)
Number of pages10
ISBN (Print)9780993548505
Publication statusPublished - 2015
Externally publishedYes
EventEngineering Structural Integrity’s Thirteenth International Conference - Manchester, United Kingdom
Duration: 19 May 201520 May 2015


ConferenceEngineering Structural Integrity’s Thirteenth International Conference
Country/TerritoryUnited Kingdom


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