加强框结构静强度可靠性分析方法

本文阐述了加强框结构静强度可靠性分析的一般方法。对优化准则法进行了改进，并应用它选取各级增量载荷作用以后的破坏元件，形成结构体系的破坏树；利用Fred Moses的增量载荷法列举结构主要失效模式所对应的安全余量方程；使用仿射空间中的数值积分法求主要失效模式的二、三阶交叉破坏概率，然后用Feng的高精度法计算结构体系的破坏概率。两个算例的结果表明，本文采用的方法计算效率高、结果正确。

Reliability Analysis Method for Reinforced Frame Structures

Three contributions of this paper will be made clear in the next threeparagraphs. Moses incremental load approach for formation of structural fault tree[3]is generally used to enumerate significant failure modes. Feng improves Moses'method[1]. But Feng's optimality criterion method has a shortcoming: it mayfail to enumerate some significant modes. In this paper, an advanced methodis presented to improve Feng's method, so the probability of failing to enumeratethe significant failure modes in structural fault tree is considerably decreased. O'Ditlevsen's narrow bounds method[5] is usually used to compute thesystem failure probability. When any one of the correlative coefficients amongfailure modes is greater than 0.6, it gives much computational error. In thiscase, Feng's method with high accuracy can be used[4]. However, bothO'Ditlevsen's and Feng's method need to calculate two- and three- order jointprobabilities by approximate formulas; these calculated probabilities are some-times in great error and make Feng's method with high accuracy fail to givehigh accuracy. In this paper, the numerical integration method in affine space[6] is used to achieve real high accuracy. In references [1, 2, 3] and [5], the reliability analysis models of somesmall and medium structures are established. In this paper, the reliabilityanalysis model of a kind of large scale structure--reinforced frame structure-- is established by means of the finite element model corresponding to thestructure. Illustrative examples are given and they confirm the efficiency of theauthors method and the authors reliability analysis model. In general, thecomputer running times for computing reliability are less than five minutes(with Super personal computer).