Abstract: In this paper,the fuzzy information in structural failure criterion is taken into consideration when calculating reliability degree of the structure. Also,the jumping issue of maximumstress point during Monte Carlo-sirnulation is dealt with.Based on the finite element methodand the concepts of fuzzy maximum stress set and minimum failure set,a global comprehensive formulation for calculating the system reliability degree is presented.Finally,the methoddeveloped in this paper is applied to the reliahility analysis of casinghead structure.The computational results can be taken a reference for production practice and structure design.

摘要： 本文考虑了结构失效准则中客观存在的模糊性以及采用Monte Carlo法对结构进行分析时,最大应力单元具有跳动性的特点,提出了模糊最大应力集和模糊最小失效集的概念,并在此基础上,建立了基于有限元法的结构模糊可靠性分析方法。应用此方法,对油田广泛采用的套管头结构进行了模糊可靠性分析。其分析结果,对生产实践及套管头结构设计,具有参考价值。

关键词: 套管头, 模糊集合论, 可靠性, 随机性