In Auburngrads/SMRD: Statistical Methods For Reliability Data

Example 1.1 - Ball Bearing Fatigue Test (Liebling & Zelen, 1956)

• Motivation for the study

  • Fatigue affects the service life of deep-groove ball bearings

  • Applying higher levels of stress further reduces the fatigue life of the ball bearings

  • There was disagreement within the industry on the appropriate parameter values to use to model the affect of applied stress on fatigue life

• Study objectives

  • Test several ball bearings at a key stress level to augment the existing failure data

  • The additional observations should result in better estimates of the parameter values used to model fatigue life as a function of the applied stress in deep-groove ball bearings

• Data Set (Table 1.1) lzbearing

  • The data are the observed number of accumulated fatigue cycles when each fatigue failure occurred

  • The data are reported in millions of cycles for $n = 23$ bearings

  • We aren't told what stress was applied to each bearing in this test

  • We must assume that the stress applied to all 23 bearings was equivalent

Auburngrads/SMRD documentation built on Sept. 14, 2020, 2:21 a.m.