结构系统疲劳寿命可靠性分析理论与算法

以满足自相容条件的概率型线性累积损伤理论为依据,在阶段临界强度分枝-约界法的基础上,提出了给定外载和使用寿命条件下计算结构系统疲劳寿命可靠度的全局疲劳寿命分枝-约界法。采用此方法可严格确保在一级和多级搜索纵深的条件下不遗漏结构系统的主要失效模式。

THEORY AND ALGORITHM ON FATIGUE LIFE RELIABILITY ANALYSIS OF A STRUCTURAL SYSTEM

By means of randomizing Miner's linear cumulative damage rule and generalizing the Stage Fatigue Life Branch-and-Bound Method, the Global Fatigue Life Branch-and-Bound Method is suggested for enumerating the significant fatigue failure modes and computing fatigue failure probability of a large scale structural system under given loads and service life. Using flexible control bounds, the problem of losing significant failure modes is completely solved in the case of one-order and multi-order searching depth and a good efficiency in convergence is obtained, about which a rigorous theoretic proof is provided. The feasibility and validity of this method for enumerating significant fatigue failure modes and evaluating total reliability of a structural sysem are also verified by practical compulation and analyzing of some type of classical structures.