2014 年 59 巻 10 号 p. 667-673
In this report, a procedure for significance test of rolling contact fatigue (RCF) life estimated by Weibull plots is introduced. This procedure generates results using random numbers followed by Weibull distribution (i.e. Weibull random number). The results can provide a relationship between the given number of test specimens and resultant significant differences at L10, L50 and L63.2 in RCF life test. This relationship is required to perform a significance test based on statistical logic. In addition, the relationship can apply to an estimation of the appropriate number of test specimen. In order to obtain the relationship without calculations by using Weibull random numbers, approximation equations are derived from a regression analysis for the significant differences calculated by using Weibull random numbers. The significance test using the approximation equations provides techniques that are easier to understand as compared with the general mathematical model, and they show enough flexibility to apply to several conditions for an arbitrary confidence level and different Weibull slopes. This new system will therefore eliminate the need for qualified experiences related to the statistical design and result interpretation for RCF life test.
