基于随机有限元法大跨度斜拉桥体系可靠度分析

大跨度斜拉桥由于存在众多不同的失效模式,导致其体系可靠度分析比较困难。但在众多失效模式中,仅有主要的失效模式对整个结构系统的失效概率起决定性作用。β约界法是体系可靠度分析中一种简单而精确的用于搜索主要失效模拟的方法。在β约界法搜索失效模式的过程中,需计算各个单元的可靠度指标。基于有限元的可靠度分析方法是一种高效和精确的可靠度计算方法,用该法研究了一座大跨度斜拉桥的体系可靠度问题。分析结果表明索的失效在整个斜拉桥的失效中起关键作用。

Stochastic finite element-based system reliability analysis of long-span cable-stayed birdges

The system reliability analysis of longspan cablestayed bridges is difficult because the failure of the structural systems may be happened in many different failure modes. But only the main failure modes contribute most to the failure probability of the structural system. The β-unzipping method is simple and reasonably accurate method to find the main failure modes. On the other hand, the reliability indices of the components need to be computed in this method. The finite element reliability method can be used for this purpose which is an efficient and accurate method for the reliability analysis. The method is applied to the system reliability assessment of a longspan cablestayed bridge. The result showed that the failure of the cables plays a key role in the failure of the total bridge.