可靠度对随机变量及失效模式相关系数的敏感度分析及其工程应用

客观存在的诸多不确定性因素使得工程不可避免地存在着风险。随着重大工程的不断涌现,人们越来越关心如何提高工程系统的安全度,降低工程结构的风险。遗憾的是如何降低工程系统的风险直至目前还没有固定的科学方法,大多是基于工程师的经验。以可靠度理论为基础,从可靠度对工程结构的某些参数的敏感性及可靠度对失效模式的相关系数入手,探讨如何从加强或削弱结构参数及失效模式间的相关性的角度出发,来进行降低结构风险的研究。给出了两个算例来说明方法在工程中的应用。

SENSITIVITY ANALYSIS OF STRUCTURAL RELIABILITY TO RANDOM VARIABLES AND FAILURE-MODE CORRELATION FACTORS AND ITS APPLICATION IN ENGINEERING

Many uncertainties cause unavoidable risk in engineering planning and decision. With more and more important projects such as Three-gorge project, South-North Water Transfer Project etc. being carried out now in China, more concerns are given to engineering safety and the decrease of risk in engineering structures. But unfortunately there is no scientific method to reduce engineering risk. Most methods are based on engineers’ experience. In this paper, reliability theory is used, starting from sensitivity analysis and including that of structural reliability to random variables and that of structural reliability to failure-mode correlation factors. Some methods are proposed to reduce the engineering risk through increasing or decreasing the values of stochastic variables or failure-mode correlation factors. Two examples are analyzed with the proposed method to show its application in engineering.