Reliability Study about the Approximation Methods of Censored Data in Fatigue

For obtaining fatigue limit and dealing with censored data, the" pair- life -weighted” is proposed in this paper. According to the fatigue testing of TA15 electron beam welded specimens, conventional methods and two methods in this article are used separately to calculate the fatigue limit and lognormal distribution parameters of the lives at different stress levels, and C-P-S-N curves are obtained and their corresponding mathematical expressions of 12 groups under 2 Confidence and 6 reliability are expressed as a three-parameter model. The results show that the" pair- life -weighted method " is in good agreement with the traditional method, when the lives have a difference of 3 times at the same stress, the fatigue limit only have a difference of 0.5%, it is the further evidence of the practicability in engineering about the traditional method.