Small sample estimation method for ε-N and P-ε-N curves utilizing mean data

Though a large amount of strain fatigue data for engineering materials are accumulated over years, they usually exist in the form of mean value in most literatures. In order to analyze such data, a small sample estimation method for ε-N curves and P-ε-N curves, based on heteroscedasticity regression analysis method, was put forward. Through analyzing accumulated mean life data under different strain-level as a whole, this method can estimate the P-ε-N curves with high confidence and reliability, which provides a basis for reliability design and life assessment.