摘要
研究现有的几种模糊随机化方法,提出用模糊等效随机变换法解决混合变量的结构系统可靠度计算问题。证明尺度变换式与模糊等效随机变换式是统一的;给出常用的线性隶属函数和正态型隶属函数经这几种方法变换所得的等效概率密度函数及其数字特征;用模糊随机化方法研究随机应力—模糊强度的模糊可靠度的计算公式和模糊应力—随机强度的模糊可靠度计算公式,从理论证明模糊可靠性与概率可靠性具有相容性,概率度量模糊变量和随机变量并存的混合不确定性结构系统可靠性是合理的;并将其应用于这种结构系统的可靠度计算。算例比较分析表明这种方法是有效的,同时也说明这些模糊随机化方法本质上虽然存在着差异,但都能很好度量结构系统可靠性,数值上具有一致性。
Hybrid uncertainty reliability analysis is an important part in structural reliability analysis. The comparisons of several various transformations of the fuzzy variables to equivalent random variables are drawn. The formula of the transformation of fuzzy variables to random variables is proposed and applied to the computation of structural reliability with hybrid uncertainty. Specific formulas of the equivalent PDFs（probability distribution functions） and their numerical characteristics are obtained, such as the linear membership function and the normal membership function. The compatibility of fuzzy reliability and random reliability is proved by means of the transformations. And probabilistic measurement of hybrid uncertain structural system is reasonable. The reliabihty computation with hybrid uncertainty is illustrated with an example for comparative study on the consistency of the transformations. The results show that methods are all effective and consistent.
出处
《机械强度》
EI
CAS
CSCD
北大核心
2008年第1期72-77,共6页
Journal of Mechanical Strength
基金
国家重点基础研究发展规划项目(973计划)(2007CB815500)资助~~
关键词
模糊变量
随机变量
结构可靠性
混合不确定性
Fuzzy variables
Random variables
Structure reliability
Hybrid uncertainty
