中长寿命轮盘应力寿命及可靠性分析方法

针对轮盘榫槽结构理论应力集中系数难确定、采用传统应力寿命法估寿误差大问题, 提出一种改进应力寿命预估法.改进方法包括:提出应力修正系数概念和一种适用于轮盘榫槽结构的理论应力集中系数确定方法, 以及应力比修正方法.一旦确定了试棒的应力修正系数, 改进应力寿命法可采用光滑棒试验数据预估复杂结构寿命, 并考虑应力集中影响.进而建立了基于改进应力寿命法的应力寿命可靠性分析方法, 并对某风扇盘进行了疲劳寿命可靠性分析, 计算概率寿命与试验寿命吻合良好. 

Methods for stress based life and its reliability analyses of discs with medium-long and long life

Considering the difficulty in calculating the stress concentration factor of mortise of a disk and the error of life is big by using the traditional stress-life method,an improved stress-life method is proposed to compute the life of disks.It includes the concept of stress correction coefficient,a new method to determine the stress concentration factor of mortise of a disk and a new method for correcting the stress ratio.When once the stress correction coefficient of the bars was computed,the improved Stress-Life method can be used to calculate disk's life with the experimental data of bars without notch,at the same time,the influence of the stress concentration is also considered.Then a new stress-life probabilistic model is built for the purpose of life reliability analysis.Finally,the fatigue life reliability of a fan disk is analyzed by the method given,and the computational results fit well with experimental ones.