基于弹性模量缩减法研究结构体系可靠度  

The elastic modulus reduction method based structural system reliability

作　　者：杨绿峰[1,2] 余波[1,2] 莫远昌[1,2] 

机构地区：[1]广西大学土木建筑工程学院 [2]工程防灾与结构安全重点实验室,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2008年第4期349-353,357,共6页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金项目(50768001);教育部新世纪优秀人才支持计划专项项目(NCET-04-0834)

摘　　要：针对现有体系可靠度理论的两大难点,基于塑性极限分析理论研究建立了体系可靠度分析的弹性模量缩减法:首先以单元的可靠指标为控制参数,定义结构的可靠指标均匀度和基准可靠指标,并建立新型的弹性模量调整策略;进而通过系统地缩减各单元的弹性模量,以模拟结构的可靠指标重分布和失效状态转移,通过一系列弹性有限元迭代分析确定结构体系的失效概率.该方法从根本上回避了现有体系可靠度理论的两大难点,避免了繁琐的失效模式分析和多模式联合失效概率的相关性分析.算例分析表明,该方法不仅适用于静定结构,而且适用于超静定结构,计算格式简单,计算精度较高.A new method for structural system reliability is proposed based on the plastic limit analysis theories in this paper, so that two problems can be tackled effectively. The reliability index is adopted as the governing parameter to define the degree of uniformity of the reliability index. Then the reference reliability index is presented. The new procedure for adjustment of elastic modulus is proposed by means of the equivalence of strain energy so as to simulate the redistribution of reliability index of element and the transition of failure mode. The failure probability and the reliability index can be achieved based on the iterative analysis of linear elastic finite element. Examples show that the proposed method is simple and effective for system reliability analysis of engineering structures,and yield results with high accuracy compared with conventional method.

关 键 词：体系可靠度 失效模式 均匀度 弹性模量缩减法 

分 类 号：TU311[建筑科学—结构工程]