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

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