随机变量间相关系数的可靠性灵敏度

基于可靠性摄动分析法包含对基本随机变量间相关系数运算这一特点,通过最大可靠性误差计算分析基本随机变量间相关系数在可靠性分析中的重要性,通过可靠性灵敏度计算分析基本随机变量间相关系数的改变对结构可靠性的影响。实例计算以及编写的相应分析程序获得基本随机变量间相关系数引起的最大可靠性分析误差、对结构可靠性的影响程度等信息,说明了本文的方法在工程实际中的应用。本文研究结果为将基本随机变量作为独立变量处理从而简化可靠性分析运算,或确定相关系数对结构可靠性的影响以及重要程度提供理论根据。

Reliability sensitivity to the correlation coefficients among random variables

Based on the characteristic of the reliability perturbation analysis including the calculation of the correlation coefficients among the basic random variables, the importance of the correlation coefficients in the reliability analysis was analyzed through calculations of the maximum error of the reliability analysis, and the effect of the correlation coefficients on the structural reliability through calculation of the reliability sensitivity. The methodology proposed in the paper was illustrated by an example, from which the information of the maximum error of the reliability analysis caused by the correlation coefficients and the effect of the correlation coefficient on the reliability analysis was obtained. The theory foundation was proposed to simplify calculation of the reliability analysis by regarding the basic random variables as uncorrelated variables and to determinate the effect of the correlation coefficients on the structural reliability and their importance level.