Rolling-element fatigue testing and data analysis - A tutorial

In order to rank bearing materials, lubricants and other design variables using rolling-element bench-type fatigue testing of bearing components and full-scale rolling-element bearing tests, the investigator needs to be cognizant of the variables that affect rolling-element fatigue life and be able to maintain and control them within an acceptable experimental tolerance. Once these variables are controlled, the number of tests and the test conditions must be specified to assure reasonable statistical certainty of the final results. There is a reasonable correlation between the results from elemental test rigs with those results obtained with full-scale bearings. Using the statistical methods of Weibull and Johnson, theminimum number of tests required can be determined. This article brings together and discusses the technical aspects of rolling-element fatigue testing and data analysis and makes recommendations to assure quality and reliable testing of rolling-element specimens and full-scale rolling-element bearings.