为了提高杜瓦结构的可靠性水平，本文提出了基于NESSUS（Numerical Evaluation of StochasticStructures Under Stress）软件的杜瓦结构可靠性分析方法。此方法将杜瓦组件的载荷、材料性能、几何尺寸等参数均作为具有某种分布特性的随机变量，通过概率分析，可获得定量的杜瓦结构可靠度值以及各个设计参数的概率灵敏度值，并由此确定关键影响因素，为提高杜瓦结构的可靠性提供设计依据。本文以杜瓦冷台支撑结构为例进行了结构可靠性分析，分析结果表明此方法可以显著提高杜瓦结构的可靠性水平。

To improve the reliability level of a dewar structure, in this paper, a NESSUS(numerical evaluation of stochastic structures under stress)based reliability analysis method for a dewar structure has been proposed. In this method, the design parameters, such as the loads, material characters, and geometry parameters, are treated as random variables with specified distributions. Through probabilistic analysis, this method can obtain the quantitative reliability index of the dewar structure and the sensitivity factors of every design parameter can be calculated. According to the analysis results, the key parameters of dewar structure reliability can be recognized which can be used to improve the dewar design. As an example, the reliability of a cold platform was analyzed in this paper. The results indicate that this method would dramatically improve the reliability of a dewar structure.