损伤容限结构的可靠性分析

 根据结构危险部位的损伤容限特性定义了剩余强度的各种状态。通过对各状态的发生及转移这~随机过程的分析,提出了用状态离散时间连续的时齐马尔可夫过程对此进行模拟。文中以结构损伤容限评定的主要内容和有关的统计资料为依据,指出了影响各状态发生及转移的主要因素,并提出了对各主要因素所引起的状态转移率矩阵和综合的状态转移率矩阵进行分析评定的方法。在此基础上发展了损伤容限结构的可靠性分析途径。由算例给出的结果还说明了本分析方法可以为损伤容限设计中的主要环节和主要参数实行有效控制提供良好的评估依据。

THE RELIABILITY ANALYSIS OF DAMAGE TOLERANCE STRUCTURE

This paper defines the residual strength status of various kinds of structural significant items according to the characteristics of the damage occurrence and growth of these items. The random process of the occurrence of the status of various kinds and the transfer among them in the period of the structure life is analysed, and it is simulated by using the time monogeneous Markov process of discrete status and successive time. In accordance with the main contents of structure damage tolerance assessment and the statistics results of relevant data, the paper points out that the major factors to influence the occurrance of the status of various kinds and the transfer among them are fatigue, fracture, accident damage and environment corrosion, and the method of estimating the status transfer ratio matrix caused by each impact factor is proposed. From which, the formula to integrate total status transfer ratio matrix is set up. Further, the instantaneous reliability of the damage tolerance structure in its life is defined, and the approach to compute the instantaneous reliability is presented. In the last section of the paper, one calculating example is given, It can be found from the example that the structure reliability of considering maintenance program is higher than that of doing not consider maintenance program. This conclusion shows that the reliability analysis approach advanced in this paper can not only be favourable for the application and development of the damage tolerance design method, but also provide the appropriate analysis basis for the effective control of the design links and the design parameters.