高效识别桁架结构主要失效模式的一种新方法

A NEW METHOD OF IDENTIFYING MAIN FAILURE MODE ABOUT TRUSS STRUCTURE

在对现有两大类主要失效模式识别方法进行深入分析基础上,针对保留的候选失效元并非都是组成失效模式必备单元的问题展开研究.利用结构力学基本理论,分析了单元失效对残余结构内力影响规律,并推导了其关系式;通过该关系式,证明了具有相同基本失效单元的失效模式间线性相关;结合概率论相关理论,得出主要失效模式一定只包含基本失效单元的结论,由此证实了组成主要失效模式的必备单元就是基本单元;基于结构几何构造分析理论,分析了结构体系的失效形式,讨论了形成结构体系失效的基本单元范围;进而采用对结构进行逐步搭建的思想,建立了基本单元最小存在范围的划分方法;与分支限界法结合提出一种新的桁架结构主要失效模式识别方法;通过算例分析,证实该方法合理有效,且具有较高识别效率,同时能保证不遗漏主要失效模式.

On analyzing two kinds of the existing identification methods of main failure mode, the problem that the reserved candidate failure elements are not all the necessary elements of failure modes has been studied. According to the basic theory of structural mechanics, the effects of failure elements on residual structure internal force has been analyzed, and the relationships have been deduced; According to the relationships, the linear correlation between failure modes which have the same basic failure elements has been proved; and based on the probability theory, it can be concluded that the main failure modes contain only basic failure elements, thus that the necessary elements of main failure modes are exactly the basic elements has been proved. Based on structure geometry analysis theory, failure modes of structural system have been analyzed, and the basic elements range of structural system failure has been discussed. And then using the idea of gradually building structure, the divided method of minimum existence range of the basic elements has been set up. A new method of identifying main failure mode about trusswork has been put forward combined with the branch bounding method. According to examples analysis, it can prove that this method is rational and has high-efficiency, and simultaneously it can ensure no omission of any main failure modes.