疲劳安全与寿命可靠性评估二次三阶矩方法

A SECOND ORDER THIRD MOMENT METHOD FOR ASSESSING THE PROBABILITY OF FATIGUE SAFETY AND LIFE

提出了疲劳安全与寿命可靠性评估的二次三阶矩方法，并且给出了常用随机变量的三阶矩计算方法，由于采用三参数威布尔分布拟合，可以较好描述各种分布形态的随机变量，与传统的一次二阶矩方法比较，该文提出的方法计算精度高，适应性强．

Because the initial crack size, the stresses, the material properties and other factors that may affect the fatigue crack growth are statistically distributed. The first order second moment method is often adopted to calculate the failure probability of industrial structures. In this paper, a new second oder third moment method is presented and a three parameter Weibull distribution is adopted to reflect the influences of the skewness of probabilistic distribution. The proposed method is obviously more accurate than the traditional first order second moment method with a case study.