压力容器筒体的非概率可靠性分析

Non-probabilistic reliability analysis on shell of pressure vessels

传统的可靠性分析采用的是概率方法,它需要不确定参量的详细统计信息以确定其概率分布。而压力容器多处于较为严苛的工作环境中,难以准确获得不确定参量的准确概率分布。为此,基于区间模型的非概率可靠性理论,用区间方法来描述压力容器筒体参数,提出压力容器筒体强度的非概率可靠性指标的计算方法。该方法仅需要知道不确定参量的边界,克服了概率方法的局限,且很大程度的降低了计算工作量。通过实例分析,表明该方法是有效可行的。

The probabilistic reliability approach is traditionally used in reliability analysis,which needs detailed statistics of uncertain parameters for determining their probability distribution.Most of the pressure vessels are operated in severe environment,and the exact probability distribution of uncertain parameters couldn＇t be obtained accurately.Thus,based on the non-probabilistic reliability theory of interval model,nterval method is used to describe the parameters,and the approach for computing the non-probabilistic reliability index of shell of pressure vessels was presented.This method just needs the boundary of the uncertain parameters,which overcame the limit of probabilistic reliability and decreased the amount of work.A numerical example in the final part of the paper illustrates the feasibility and availability of the proposed approach.