一种不依赖失效路径的结构体系可靠度分析方法  

A failure-path independent method for analysis of structural system reliability

作　　者：杨绿峰[1] 吴文龙[1,2] 余波[1] 

机构地区：[1]广西大学土木建筑工程学院工程防灾与结构安全教育部重点实验室,南宁530004 [2]福建省建筑科学研究院,福州350025

出　　处：《中国科学：物理学、力学、天文学》2014年第11期1220-1231,共12页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:51168003;51368006);广西自然科学基金(编号:2012GXNSFEA053002)资助项目

摘　　要：传统的结构体系可靠度分析方法依赖于结构失效路径的分枝和约界技术,导致主要失效模式难以识别、体系失效概率计算工作量巨大.鉴于此,本文结合弹性模量缩减法和随机有限元法,提出了一种不依赖失效路径的结构体系可靠度分析方法.首先利用随机有限元法计算结构的随机响应量,据此定义单元承载比和基准承载比,以判别结构在不同受力状态下的高承载单元.然后利用变形能守恒原理建立结构内力重分布和损伤演化模拟的随机弹性模量缩减法,进而根据塑性极限状态下高承载单元的弹性模量缩减幅度确定结构主要失效模式,并利用多失效模式的联合失效概率计算结构体系可靠度.研究表明,该方法消除了传统方法中潜在失效路径对主要失效模式识别和失效概率计算的干扰,能够取得更高的计算效率和精度.In order to overcome the disadvantages of traditional system reliability methods in the identification of significant failure modes and calculation of joint failure probability, a failure-path independent method is presented for structural system reliability analysis by combining the elastic modulus reduction method and the stochastic finite element method（SFEM）. The stochastic responses by the SFEM were employed to define the element bearing ratio and the reference EBR, based on which an efficient dynamic criterion was developed for identification of highly stressed elements. The stochastic elastic modulus reduction method was proposed for simulation of internal force redistribution and damage evolution based on the principle of deformation energy conservation. The significant failure modes of structural system were identified according to the elastic modulus of the highly stressed elements in the limit state, while structural system reliability was calculated based on the joint failure probability of multi-failure modes. Investigation demonstrated the advantages of the proposed method over the traditional system reliability methods and its high accuracy and efficiency.

关 键 词：体系可靠度 主要失效模式 内力重分布 弹性模量缩减法 随机有限元法 

分 类 号：TB114.3[理学—概率论与数理统计]