桨叶可靠性分析方法

本文给出二维疲劳裂纹扩展门槛值分布函数,建立二维应力—门槛值干涉模型。该模型可用于含初始缺陷或意外损伤的螺旋桨叶无限寿命可靠性分析和设计,得到桨叶可靠度与初始裂纹尺寸之间的函数关系式。考虑到随使用时间增长,桨叶遭受意外损伤的可能性将不断增大,损伤的程度也不断加重,文中还给出桨叶在无限寿命条件下的检修周期。该方法也可用于其它含裂纹构件以及复合材料桨叶的无限寿命可靠性分析和检修周期确定。 

A METHOD OF RELIABILITY ANALYSIS FOR PROPELLER BLADES

A distribution function of two dimensional threshold is given for fatigue crack propagation.A two dimensional stress threshold interference model is set up.The model is applicable to the reliability analysis and design of infinite life for propeller blades or other structural members with initial defects and accident damage.The functional correlation between the reliability of no crack growth and the initial crack sizes is obtained from the model and the maximum permissible crack sizes can be determined according to a given reliability level.In consideration of the fact,that the longer the service time,the greater the probability of accident damage,the overhaul periods of propeller blades with high reliability are also given.