基于更新支持向量的大跨度斜拉桥体系可靠度分析

发布时间：2018-03-30 04:25

本文选题：桥梁工程　切入点：体系可靠度　出处：《计算力学学报》2015年02期

【摘要】：针对斜拉桥静力体系可靠度分析中隐式功能函数重构和繁杂失效路径的特点,提出了一种基于更新支持向量的体系可靠度分析方法,将传统的用于构件可靠度分析的支持向量机(SVM)改进并应用于斜拉桥体系可靠度分析。该方法主要有4个步骤:首先通过构件的敏感分析识别斜拉桥的主要失效路径;其次采用最小二乘支持向量机(LS-SVM)对斜拉桥的隐式功能函数进行重构,并通过Monte-Carlo抽样得出构件的可靠指标;然后根据已经更新的有限元模型对支持向量进行更新,得出相关构件失效后的剩余构件的条件可靠指标;最后由结构体系的失效树和串并联关系得出斜拉桥的体系可靠度。主跨为420m的混凝土斜拉桥算例分析表明了上述算法的有效性和实用性,同时也获得了该斜拉桥的主要失效路径并识别了影响其体系可靠度的主要构件。
[Abstract]:According to the characteristics of implicit function reconstruction and complicated failure path in the reliability analysis of static system of cable-stayed bridge, a new reliability analysis method based on update support vector is proposed. The traditional support vector machine (SVM) for component reliability analysis is improved and applied to the reliability analysis of cable-stayed bridges. There are four steps in this method: firstly, the main failure paths of cable-stayed bridges are identified by the sensitivity analysis of components; Secondly, the implicit function function of cable-stayed bridge is reconstructed by using least square support vector machine (LS-SVM), and the reliability index of components is obtained by Monte-Carlo sampling, and then the support vector is updated according to the updated finite element model. The conditional reliability index of the remaining components after failure is obtained. Finally, the reliability of the cable-stayed bridge is obtained from the failure tree and series-parallel relationship of the structural system. An example of a concrete cable-stayed bridge with a main span of 420 m shows the effectiveness and practicability of the above algorithm. At the same time, the main failure paths of the cable-stayed bridge are obtained, and the main components which affect the reliability of the cable-stayed bridge are identified.
【作者单位】：长沙理工大学桥梁结构安全控制湖南省工程实验室;
【基金】：国家自然科学基金(51378081) 桥梁结构安全控制湖南省工程实验室开放基金(14KD08)资助项目
【分类号】：U448.27

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