非概率可靠指标和可靠度定义的比较研究

首先对几种主要的非概率可靠指标、可靠度进行了整理介绍;然后针对区间和椭球两个基本模型,对非概率可靠指标和可靠度的定义、几何意义以及计算公式进行了系统的比较分析。结果表明:线性情况下,区间可靠指标对结构功能函数具有不唯一性,椭球可靠指标与结构功能函数一一对应。因此,基于均值和离差之比定义的非概率可靠指标不适用于区间模型用来衡量结构的可靠程度。本文还将区间可靠指标与可靠度、椭球可靠指标与可靠度进行了比较,并将非概率可靠度与服从均匀分布、正态分布的概率可靠度以及服从三角形分布的非精确概率可靠度进行了比较,结果表明:区间模型相对于其他模型较为保守,椭球可靠度与概率可靠度和三角形分布下的非精确概率可靠度相接近。

Comparative study on the definitions of non-probabilistic reliability index and reliability

In view of the uncertainty problem in practical engineering,the non-probabilistic reliability emerges when the probabilistic reliability theory developed to a bottleneck.The non-probabilistic reliability model can still measure the reliability of the structure in the case of less information,so it has an important role in practical engineering.Based on the existed research,several major non-probabilistic reliability indicator and reliability definitions are studied,and it is also pointed out that there are non-uniqueness problem in the definition of interval reliability indicators and a preliminary analysis is made.Then the reliability index and reliability of interval and ellipsoid are compared,analyzed and summarized.Finally,the non-probabilistic reliability is compared with the probability reliability obeying the uniform distribution,normal distribution,and the inaccurate probability reliability obeying the triangle distribution,which lays a foundation for the further study of non-probabilistic reliability.