Abstract: Owing to the uncertainty of random and cognition existed in complex engineering system,to realize the balance between efficiency and accuracy of multidisciplinary reliability analysis,a unified multidisciplinary reliability analysis method with quadratic polynomial approximation and chi-squared distribution was proposed based on analyzing the reason of low computational accuracy caused by first-order reliability method in computational process.The method consisted of four modules: multidisciplinary system analysis,system sensitivity analysis,unified model of reliability analysis and calculating multidisciplinary reliability.The proposed strategy with its main section could provide a high accuracy solution for RBMDO,and its implementation process was described in detail.Two examples were used to verify the effectiveness of the proposed method.

Key words: mixed uncertainties, multidisciplinary reliability analysis, first order reliability method, chi-squared distributions

摘要： 复杂工程系统往往包含随机不确定性和认知不确定性,为实现多学科可靠性分析效率和精度的平衡,在深入研究一阶可靠性分析方法计算过程中计算精度低的根本原因的基础上,采用序列化思想提出一种能够处理多源不确定性共存情况下的统一多学科可靠性分析方法,该方法由多学科系统分析、系统灵敏度分析、统一可靠性分析模型建立和可靠度求解组成。详细描述了所提方法的执行过程,并通过两个算例验证了其有效性。

关键词: 混合不确定性, 多学科可靠性分析, 一阶可靠性分析方法, 卡方分布