疲劳分散系数的分类及其取值

 本文提出疲劳分散系数可以分为疲劳试验用的分散系数和理论计算用的分散系数。其中每一种又可分为裂纹形成寿命的分散系数和裂纹扩展寿命的分散系数。 本文还对各类分散系数的取值进行了研究,并给出了它们的具体数值。本文同时还对各国所用分散系数的计算公式和取值差别进行了评述。

THE CATEGORIES AND VALUES OF FATIGUE SCATTER FACTORS

This paper considers that fatigue scatter factors should be classified into 2 categories for fatigue testing and for theoretical calculation. There is some difference in the values of scatter factors of these two categories.Such difference is primarily due to the difference in both the parameters（standard deviations）and the numbers of testing specimen which are used to calculate the scatter factor.In addition, each of above two scatter factors should be further divided into 2 subcategories: for crack initiation and for crack growth.The difference in the values of these two subcategories is chiefly due to that the standard devia- tions and the objective requirements for the calculation and testing of crack initiation life and crack growth life are different.The values of scatter factors of the above mentioned categories are given based on a number of fatigue test data, and some equations for calculating the scatter factor used in some countries are reviewed in this paper.