摘要
复杂结构的疲劳断裂破坏往往是多点的,并且各点之间具有一定的相关性,因此,已有的单点寿命可靠度的计算方法不适用于多点疲劳断裂寿命可靠性评估问题。文中针对多点失效疲劳寿命和裂纹扩展寿命为正态或对数正态分布的情况,并且计及不同失效点疲劳寿命间和裂纹扩展寿命间相关的特征,推导出一种新的可进行数值计算的积分表达式。在进行具体的数值积分时,用重要抽样(importance sampling)的概念提高积分效率。该方法能解决结构多点失效寿命可靠度的计算问题。理论与算例表明方法是有效的。该方法的原理也可推广于其他非正态与非对数正态分布的情况。
The estimation methods of fatigue life based on the single point failure mode can not be used in reliability estimation of multi-point failure mode in complicated structure because correlation between multi-point failure mode must not be neglected.A new integratable formula,which considering feature of correlation between multi-point failure mode and crack growth life,has been promoted for normal distribution or log-normal distribution of multi-point failure mode fatigue life and crack growth life.The importance sampling is used to improve compute effective in numerical integration.This method can be used to solve the problems about reliability estimation due to multi-point failure mode in very large engineering structure.The numerical results of a model are verified by the test data.The principle of this method can also be prompted to non-normal distribution and non-log-normal distribution.
出处
《机械强度》
CAS
CSCD
北大核心
2011年第3期363-367,共5页
Journal of Mechanical Strength
关键词
结构
多点失效
可靠度
重要抽样法
Structure
Multi-point failure mode
Reliability
Importance sampling
